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THE :
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BOTANICAL GAZETTE
EDITOR
JOHN MERLE COULTER
VOLUME LIV
JULY-DECEMBER, 1012
WITH THIRTY-SIX PLATES, ONE HUNDRED AND ELEVEN FIGURES,
AND TWO PORTRAITS
THE UNIVERSITY OF CHICAGO PRESS
CHICAGO, ILLINOIS
» ot. Garden
1913. -
TABLE OF CONTENTS
The development of the vascular structure of
Dianthera americana (with plates I-IV) - W. Ralph Jones
The toxic action of organic compounds as modified
by fertilizer salts (with five figures)
Oswald Schreiner and J. J. Skinner
The effect of external conditions upon the after-
ripening of the seeds of Crataegus mollis. Con-
Sam from the Hull Botanical Laboratory
Wilmer E. Davis and R. Catlin Rose
The nice at the stomata ‘of certain Cretaceous
conifers (with plates Vand VI) - - W. P. Thompson
Spermatogenesis in Equisetum. ConcHhitions
from the Hull Botanical — 158
(with plates VII and VIII) - Lester W. Sharp
The primary color-factors of pia eid che
inhibitors of Papaver Rhoeas - - George Harrison Shull
are from the Rocky Mountain Her-
rium XI (with two figures) - Aven Nelson
Beneficial effect of creatinine and creatine on
growth (with one figure) - J. J. Skinner
The life history of Aneura pinguis. Constbutions
from the Hull Botanical sey I 39 —
plates IX-XIT)_ - Grace L. Clapp
Plant geography of North Senteal ie et
Contributions from the Hull Botanical Labora-
tory 160 (with seven figures) - J. R. Watson
The perfect oe of Actinonema rosae (with oe
XIII - Frederick A. Wolf
Undescribed hate fsb Gustenala a other
Central American Republics. XXXV - John Donnell Smith
Influence of os on the toxic action of
cumarin - J.J. Skinner
Comparative anatomy of dune pans Cont:
butions from the Hull Botanical eT
161 (with thirty-five figures) - Anna M. Starr
Parnassia and some allied Sena vith plates
-XVII) - - Lula Pace
Development of the microsporangia and micro-
spores of Abutilon T, ree Sa aati twelve
figures) > - - V. Lantis
v
PAGE
33°
ieee ni of barium chloride 6 ———
vi CONTENTS [VOLUME LIV
PAGE
The development of Blastocladia es eas n. sp. ;
(with plates XVIII-XX) J.T. Barrett 353 4
The orchid embryo sac (with siaéde XXIL-XXIID Lester W. Sharp 372 :
Growth studies in forest trees. 1. Pinus = P
Mill. (with plates XXIV and XXV) Harry P. Brown 386
Contributions from the Rocky Aonstain: Her- 3
arium. I - Aven Nelson 404
Two species of eeiais: Conttivetions fon the 4
Hull Botanical oe 162 (with four a
figures)- —_ - - Charles J. Chamberlain 419 ©
Life history of Cutleria. Conttibations from the E
Hull Botanical Laboratory 163 (with fifteen
figures and plates XXVI-XXXY/V) - - Shigéo Yamanouchi 441 4
The nature of the Jaagiides and tolerance of plants 4
in bogs - Alfred Dachnowski 503
ge oe uieuts of ‘belie delersivin ‘(with ‘ 2
V1 and six figures) eo C. Stuart Gager 515
The hit spike of Botrychium. Contributions
from the Hill Botanical Lsboratory. x64 -
(with twenty-one figures) _—- - O. O. Stoland 525
Plants which require sodium (with two ‘tenes - W.J.V.Osterhout 532 =
BRIEFER ARTICLES— iE |
Eduard Strasburger (with two portraits) aaa J Chamberlain 68 —
A note on the generations of Polysip a
(with one figure) - George B. Rigg ‘ead Annie D. Dalgity 164
Lambert C. Dwight Marsh :
Artificial eS of ae grains (with |
one figure)- — - - - = W. P. Thompson
A new species of Anirchose - - <A. S. Hitchcock
Evaporation and the stratification of vegeta
tion (with one figure)- —-
The perfect ae of the Ascocyta 0 on the hairy
George D. Fuller
vetch - -
Gautieria in the eens: United States - .
CURRENT LITERATURE -
For titles of book reviews see bade under
author’s name and reviews
Papers noticed in “Notes for Students” are
indexed under author’s name and subjects
George F. Atkinson
George F. Atkinson
DATES OF PUBLICATION
No. 1,. July 15; No. 2, August 16; No. 3, lee 21; No. 4, October
3s; No. ‘Ss wesraiqress £3; No. 6, December 16
- 73; 166, 253, 339, 427, 549
bs. |
dW
re eee
:.
r.
CV See ee
ERRATA
. I, to title add index', and append footnote Contribution from the Botanical
Laboratory of the Johns Hopkins University, No. 24.
51, line 3 from bottom, for than read then.
57, line 14 from top, for carpel read carpels.
79, footnote 2, for VOLGER read VOGLER.
88, footnote 34, for Compes, RAout read ComBEs, RAovL.
. 127, change lines 14-20 to read as follows: be 1 white-flowered to 1 purple-
flowered, or in this particular family 13 white-flowered to 13 purple-
flowered, to which expectation the observed result is not in sufficiently
close agreement even considering the small number of individuals. If
the rubrum parent were heterozygous in respect to both the primary
factors for color, C and R, it being assumed that the album parent
‘lacked both these factors, a 3:1 ratio would result.
127, line 28, omit also.
148, line 19, for CASTILLEJA VISCIA pad CASTILLEJA VISCIDA.
164, line 19, omit on before Griffithsia and Delesseria.
164, line 21, insert regularly before borne.
165, legend of fig. 1, for a Polysiphonia (?) read the plant referred to in
this note.
191, last line, for Eracheinungen read Erscheinungen.
208, line 8, for practically read partially.
235, line 8 from bottom, omit hyphen between subtus and fusco.
252, line 11, for 37.095 read 37.95.
269, line 13, for into read in to.
274, line 11, for slight read slightly bccalen®:
277, line 1 of Celtis table, for (87-72) read (27-72).
281, line 1 of Ostrya table, for (66-95) read (66-93).
297, line 11 from bottom, after reported insert (3).
393, line 2, for began read begins.
405 for Calochortus umbellatus read Calochortus euumbellatus; line ro
from bottom, for C. wmbellatus read C. euumbellatus.
419, line 5, for in the Tropic read on the Tropic.
428, footnote 2, for 1912 read ror11.
‘Tol. LIV N
THE
BOTANICAL GAZETTI
Pr July ror2
: 3 Editor: JOHN M. COULTER
CONTENTS
, The Development of the Vascular Structure of Dianthera
a Americana _ W. Ralph Jones
The Toxic Action of Organic Compounds as Modified by —
Fertilizer Salts Oswald Schreiner and J. J. Skinner
The Effect of External Conditions upon the After-Ripening
of the Seeds of Crataegus ony
ilmer E. Davis and R. Catlin Rose
The Gira of the Stomata of Certain Cretaceous Conifers
W. P. Thompson —
Briefer Articles ee .
* Eduard Strasburger Charles J. Chamberlain
Current Literature
The University of Chicago Press
CHICAGO, ILLINOIS
Agents e
“THE CAMBRIDGE UNIVERSITY PRESS, a and Eatinbecreh a
WILLIAM WESLEY & SON, Lon. :
- | ‘TH, STAUFFER, Leipzig Eat ;
; THE | MARUZEN-KABUSHIKE KAISHA, 7 Tokyo, Ovake, Kyoto
= wee
Che Botanical Gazette
A Monthly Foucnal Embracing all Departments of Botanical Science
Edited by JoHN M. CouLTER, with the assistance of, other members of the botanical staff of. the
niversity of Chicago,
Issued July 15, 1912
Vol. LIV CONTENTS FOR JULY 1912 No. 1
THE DEVELOPMENT OF THE VASCULAR STRUCTURE OF DIANTHERA AMERI-
CANA (wire PLATES LIv). W. Ralph Jones © - = = . I
THE Say ACTION OF ORGANIC COMPOUNDS AS MODIFIED BY FERTILIZER
Sé S (wits FIVE FiGURES), Oswald Schreiner and J. J. Skinner - 31
THE EFFECT OF EXTERNAL CONDITIONS UPON THE AFTER-RIPENING OF THE
SEEDS OF CRATAEGUS MOLLIS. Ae sp aia FROM THE Hv1iL BOotTANICAL
ae _LaBorATorY 157. Wilmer E. Davis and R. Catlin Ros 49
THE: STRUCTURE OF -THE reads OF CERTAIN .“CRET, ACEOUS CONIFERS
. (wit: PLATES V AND v1). W.P. Thompson - - Me SA
BRIEFER ARTICLES : : = ;
; _ Epu ARD STRASBURGER (wir TWO PORTRAITS). Charles.J. Chamberlain - - - . ---68
CURRENT LITERATURE :
2 WOOR REVIEW EWS . ~ . = . zm 2 ie : eae ey
‘CHICAGO TEXTBOOK. AN ELEMENTARY TEXT
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VOLUME LIV NUMBER I
a ILE
BOTANICAL GAZETTE
Jibs 1042
THE DEVELOPMENT OF THE VASCULAR STRUCTURE
OF DIANTHERA AMERICANA
W. Rate JONES
(WITH PLATES I-IV)
In 1907, THEO. Hot (5), in describing the anatomical structure
of Dianthera americana, called attention to the ‘“polystelic”’ con-
dition of the stem. This paper seems to be the only one ever
published on this intensely interesting plant. So at the suggestion
of Professor DuNcAN S. JoHNson, I have made a study of the
ontogenetic development of the stelar structure in order to find out
how the ‘‘polystelic” condition of the mature plant is derived.
The material studied consisted of seedlings grown in the labora-
tory and greenhouse from seeds collected near the Chain Bridge
(over the Potomac River about four and one-half miles above
Washington, D.C.), of seedlings collected at the Chain Bridge, and
of mature plants from Chain Bridge and from near Betterton, Md.
Most of the material studied was imbedded in paraffin, and
sectioned 5-10 # thick. Various stains were used, but the best
results were obtained with methyl green and acid fuchsin.
Dianthera americana is a perennial herb, with an erect stem
3-9 dm. high, grooved and angled, usually simple, and having
opposite, simple, linear-lanceolate leaves 75-150 mm. long and
6-15 mm. wide. At the Chain Bridge, the plant grows in the tide
pools on the rocky flats on the north side of the river, and also along
the banks of the Chesapeake and Ohio Canal, which at this point
runs parallel to the river just back of the flats. The plant produces
flowers from May on through the summer, ripening its fruits from
I
2 BOTANICAL GAZETTE [JULY —
about the middle of July to the end of summer. The fruit, a
loculicidal two-celled capsule, dehisces violently, often throwing
the four seeds a distance of several decimeters. The seeds germi-
nate very soon after being shed, the seedlings reaching a height of
about 2 dm. by the end of the growing season. Branches formed
in the axils of the basal leaves, and at first growing upward, soon
curve, and grow downward to just below the surface of the water,
then take a nearly horizontal direction. These stolons, becoming
o.5~-1 dm. long, send out adventitious roots at the nodes that pass
downward into the mud.
At the end of the growing season, the vertical shoot dies down
to just below the usual level of the water, usually to the top of the
first node below the surface. The rest of the stem remains green
and apparently in good condition for some time, but gradually
rotting. The stolons, with their scalelike leaves, where exposed to
the light, remain green throughout the winter, as do also the upper
parts of the adventitious roots. In the spring, the terminal bud of
the stolon again starts its activity, turning upward, and sending
up a vertical shoot into the air. This shoot develops elongated
leaves, and rarely branches from near the base. The basal buds,
however, usually produce the rhizomes by means of which the plant
perennates. Buds formed in the axils of the upper leaves develop
into the capitate-spicate inflorescences of violet or nearly white
flowers.
At Betterton, Md., the plant grows under different conditions.
Instead of growing in the water, it grows in the sand just above the
level of high tide; the rhizomes grow about on the level of the top of
the moist sand, the lower one to three internodes of the aerial shoot
being buried in dry sand. The basal branches grow upward a few
centimeters, turn down, and then become horizontal, growing along
the top of the moist sand at a depth of 5-10 cm. below the surface.
othe
ses AS
a A
The basal part of the erect shoots and also the rhizomes, there- a
fore, are without chlorophyll. Although many discharged capsules
were seen, I could find no trace of seedlings, so I cannot say that =
the life-history here is the same as at Chain Bridge, but from the a
time of flowering and of the ripening of the seeds, and from —
the general habit of the plants, I see no reason for believing that — ,
there are any marked differences in the general life-history. :
1912] : JONES—DIANTHERA ce
As Horm (5) has pointed out, both the vertical aerial stem and
the horizontal submerged rhizome show, in a cross-section of an
internode, six peripheral and one central bundle, each of leptome,
hadrome, and pith, and each completely surrounded by a thin-
walled endodermis, each having, therefore, the appearance of a
complete stele (fig. 8). For this reason, Hot says that the plant
is polystelic; from its development, however, it will be seen that
it is really astelic.
At each node there is a fusion of the six peripheral meristeles to
form a complete ring of vascular tissue, which breaks up in a very
regular way to form the six peripheral meristeles of the internode
above (fig. 1). Each of the bundles of the lower internode divides
at the node to form a Y; then each branch fuses with a branch of
the adjacent Y, thus giving rise to the six peripheral bundles of the
next internode. The single leaf traces join the vascular system of
the stem at the crotches of two opposite Y’s. The two bundles
which supply the traces are usually, though not always, larger than
the other four. There is also a connection made, at each node,
between the central bundle and the peripheral ring of vascular
tissue by means of a transverse arm, coming out from the central
bundle at right angles to it and fusing with the vascular ring just
below the insertion of the leaf traces (figs. 3-8 show a series of
transverse sections through the node). The structure of the node
next above or next below the one described is exactly the same,
except that its plane of symmetry is at right angles to that of the
adjacent one, as is shown in fig. 1. A diagram of the path of
the bundles in a mature plant is shown in fig. 2. ©
The seeds
The seeds (figs. 11 and 12) are much flattened, and are nearly
circular in outline. They are about 2-3 mm. in diameter, and
about o.75-1 mm. in thickness. On the lower side the edge of
the seed is slightly hollowed out to form a pocket in which lie the
hilum and the micropyle. The testa is brown in color, and has a
much roughened surface, owing to the distortion of the underlying
cells, of which there are two to four layers (fig. 10). The walls of
the epidermal cells are thickened in bands which fuse at some
places, and at others taper to a point and disappear. The inner
4 BOTANICAL GAZETTE [JULY
cells are thin-walled, and are much distorted in shape. The endo-
sperm is represented by a thin pellicle, usually two cells in thickness,
except at the lower edge of the seed, where it thickens to form a
mass of appreciable thickness, which forms a cap over the free
end of the hypocotyl. The well developed embryo nearly fills the
seed. The two large cotyledons are flat, nearly circular in outline,
accumbent, the curved hypocotyl lying closely against the edges of
the cotyledons, and being free only at the end. The seed, there-
fore, corresponds very closely to that of Dianthera nodosa Benth.
& Hook. as described by ScHAFENIT (8, p. 65).
The epidermis of the hypocotyl is composed of small cells which :
are elongated vertically. The cortex consists of about ten layers
of cells, radially arranged, and of larger diameter than those of the
epidermis. They are flattened vertically, and appear nearly square —
in cross-section. The innermost layer appears in no way different —
from the rest of the cortex. One striking feature of this layer,
however, is the division of its cells, on each side of the central
cylinder between the protoxylem poles, to form two layers (fig. 14).
Schizogenous air cavities, of small diameter, but of considerable
length, have already formed between the angles of the adjoining —
cells.
The central cylinder is sharply marked off from the surrounding
cortex, owing to its greatly elongated cells of very small diameter —
(fig. 14). Just below the insertion of the cotyledons, the central
cylinder divides to form the two procambial cotyledonary traces —
(fig. 13).
Germination
The earliest stages of germination have not been observed in
the field. Seeds brought into the laboratory and soaked in water —
swelled about 0.5 mm. in diameter and about 0.25 mm. in thick-
ness. These soaked seeds were then placed in a moist chamber,
either on wet filter paper or on wet sand. The testa soon split, the
hypocotyl pushing through. Further growth now forces upward :
the upper end of the hypocotyl and the cotyledons, often carrying _
the testa still clinging to one or both of the cotyledons. The lattet —
soon become green, continue their growth, and function photo- —
synthetically for some time. The plumule is rather tardy in
starting its growth.
Sa le aa:
Sao RIS Need Seiten Tea FS Cee PS AEE, Ry eee re ene ne RIE EN aS tr
Pe eer MEN eS Sr eee
1912] JON ES—DIANTHERA 5
For ease of description, we will divide the growth of the seedling
into stages corresponding to the number of pairs of leaves present.
STAGE I
The first seedling stage (fig. 15) shows the elongating hypocotyl
well out of the testa, pushing upward the cotyledons which are
frequently still inclosed within the testa. All the endosperm
found in the seed has been used up. The primordia of the first
pair of leaves are beginning to develop, but no sign of differentiation
of the foliar traces has yet appeared. From each cotyledon one
double bundle enters the hypocotyl (fig. 16). These bundles
approach each other, and very soon come together to form the
central cylinder.
In the middle of the hypocotyl, a cross-section shows an epider-
mis of cells slightly elongated radially, the inner and side walls
thin, the outer walls slightly cutinized; the cortex, about 10-12
cells in thickness, the outer two or three layers of irregularly
arranged cells, which are beginning to show a slight thickening and
later forming a typical collenchyma. The remaining inner layers
of the cortex are made up of rounded thin-walled cells, very regu-
larly arranged in radial rows, their walls being in contact except at
the angles, where there are formed small schizogenous air cavities,
which latter extend vertically for a considerable distance. The
innermost layer of the cortex is not modified in any way, being like
the other cells of the inner part of the cortex in size, shape, and
content of cells.
The central cylinder, or stele, is very sharply marked off from
the surrounding cortex, being made up of much smaller cells except
at the very center. The pericycle is of one layer except opposite
the xylem poles, where it is of two layers. The xylem is arranged
in two opposite groups, the protoxylem being exarch. The four
phloem groups are placed one on each side of the xylem poles. The
rest of the central cylinder is of thin-walled parenchyma, small
near the periphery, but becoming much larger at the center. There
are no air spaces in the central cylinder.
Transition.—In the petiole of each of the cotyledons is a double
bundle, the protoxylem of which occupies an endarch position.
As the two bundles of the cotyledons enter the hypocotyl, there is
6 BOTANICAL GAZETTE [JULY
a rotation of the xylem, the protoxylem becoming exarch. On
reaching the transition region, near the base of the hypocotyl, the
phloem of each bundle divides, and passes to the right and left of
the xylem. Each half moves to the side of the stele, finally fusing
with a half of the phloem from the other bundle. This forms a
typical diarch root, the transition being that of Type III of VAN
TrecHeM. Fig. 17 shows a diagram of the path of the vascular
tissue at this stage.
STAGE II
In the second stage, the first pair of leaves have enlarged
sufficiently to be seen easily by the naked eye (fig. 19). The
primordia of the second pair of leaves are not differentiated until
near the end of this stage. The bases of the cotyledons have fused
to form a short tube. The leaves of the first pair are opposite and
are decussate to the cotyledons. As they develop, there begins the
differentiation of.a single vascular bundle for each, the differen- 3
tiation beginning at the node, passing outward into the leaf, and —
downward into the stem, passing through the very short epicotyl
into the hypocotyl, and becoming inserted between the cotyledonary
bundles, the protoxylems finally disappearing near the base of the —
hypocotyl.
There have also started to develop two buds, one axillary to
each cotyledon, but at this stage neither shows any differentiation
of vascular tissue. A diagram of the course of the vascular tissue
at this stage is shown in fig. 18.
The cortex and epidermis are very nearly as-in the preceding ;
stage, the angles of the outer cortical cells being more thickened,
however, and the outer wall of the epidermal cells being heavier
than before. Glandular hairs of the type found on the mature
plant (figs. 26 and 27) are numerous on the hypocotyl and
cotyledons.
At the close of this period of development, a bundle develops
Ep Ce ee be te IS ec het
on each side of the stem between the two traces of the first pair of
leaves. These bundles, at the lower end, are forked just over the _
cotyledonary traces, the forks being inserted on either side of the
_ traces, between them and the bundles from the first leaves. At —
the upper end, the bundles fork, the branches passing off nearly —
1912] JONES—DIANTHERA 7
at right angles to the main bundle, and being inserted on the sides
of the leaf traces of the first pair of leaves. There is thus formed
a complete ring of vascular tissue in the first epicotylar node.
Rarely the forks at the base of the bundles are of very unequal
size, or one of the bundles may even fail to divide, in this case
merely bending aside, and becoming inserted on one side or the
other of one of the cotyledonary traces. The direction of differ-
entiation of these side bundles seems to be acropetal, but this
could not be made out definitely. The cross-arms connecting the
bundles with the traces of the first pair of leaves, however, are
undoubtedly younger than the main part of the bundles. Fig. 20
shows the course of the bundles at this stage.
STAGE III
With the development of the second pair of opposite leaves at
right angles to the first pair, and directly over the cotyledons, we
have the third stage (fig. 22). At the insertion of each of these
leaves, there starts to differentiate a single bundle, passing outward
into the leaf, and downward through the stem, becoming inserted
in the crotch of the fork of the bundle just developed at the close
of the preceding stage (fig. 21).
If we now examine this latter bundle (fig. 23), we find that it
possesses three protoxylem elements, one being derived from the
newly developed trace of one of the second pair of leaves, the other
two connecting, one through each of the horizontal connecting
branches, with the outgoing leaf traces of the first pair of leaves. |
At the lower end of the bundles (figs. 24 and 25), one of the pro-
toxylems passes out along one of the forks; the other two, which
have been closely applied to each other throughout the whole
length of the bundle, pass out the other. These bundles at first
have the appearance of being double, the two parts being separated
by a narrow parenchymatous (medullary ?) ray, but being, later at
least, entirely surrounded by a complete endodermis.
A cross-section (fig. 28) through the middle of the second
epicotylar internode shows an epidermis, or rather protoderm, of
thin-walled cells, sharply marked off from the internal cells.
Within this protoderm is a meristematic tissue of cells practically
all alike, showing no differentiation into cortex and central cylinder,
8 BOTANICAL GAZETTE [JULY
and with no air spaces. In this ground tissue are imbedded the
two procambial strands of the traces of the second pair of leaves.
In the middle of the node below, there is to be seen a ring of
vascular tissue inclosing an area of rounded parenchymatous cells
similar in appearance to the cortical cells surrounding the vascular
tissue. The inner layer of the cortex differs from the remaining
cortical cells only in being more tightly placed together, thus
forming a sheath. There is as yet no thickening of the walls of
the cells forming this sheath.
Immediately below this node, the sheath sinks in between the
four bundles, breaks, the ends turn in and form a complete sheath
around each of the bundles, inclosing also a small amount of the
undifferentiated parenchyma (pith?) on the inner face of each
bundle. This condition persists throughout the internode. At the
forking of the two opposite side bundles (figs. 24 and 25), the
sheath sinks in between the forks, and so forms a complete sheath
around each branch. On entering the cotyledonary node, these
sheaths break on the inner face of the bundles, open out, the ends
of each fuse with those of the adjacent bundles, forming thus 4
complete, but at first irregular, sheath around the entire central
cylinder of the hypocotyl, which sheath continues downward into
the root. At places, the bundle sheaths in the basal epicotylar
internode show the characteristic Casparian dots on the side walls;
this is also true of the sheath around the central cylinder of the
hypocotyland root. At this stage, however, the sheath is extremely
irregular, being often of two layers for a short distance, and in
most places showing no special endodermal characteristics.
A cambium has appeared in the bundles from the first pair of
leaves, but very little secondary tissue has as yet been formed.
_In the hypocotyl there is a much interrupted cambium which has
formed a little secondary tissue. At a later stage, the cambium
forms a complete ring, and so develops a complete ring of secondary
vascular tissue. In the root there is now to be found an inter-
rupted cambium, which later becomes complete except at the
protoxylem poles. The older primary root, therefore, will have
two crescent-shaped masses of secondary tissue, the horns of which _
come together opposite the protoxylem poles.
Ig12] JONES—DIANTHERA 9
The buds, found at the preceding stage in the axils of the
cotyledons, have developed somewhat, each having now two very
small leaves, each of which furnishes a single trace which passes
downward into the hypocotyl. These become inserted, one on
each side of the cotyledonary trace, between it and an arm of the
forked bundle entering from above.
The bases of the first pair of leaves were at first distinct, but
they have by this time grown together to form a short tube. This
is the case with all the later formed leaves. A bud is starting to
develop in the axil of each of the first pair of leaves, but at this
stage has developed no vascular tissue.
From now on, the order of differentiation of new bundles is the
same as that just described. At the close of each stage, there
develops a pair of opposite bundles, each double in appearance,
having two groups of protoxylem and protophloem elements
separated by a parenchymatous ray. These bundles fork below,
the forks being inserted between the traces of the underlying pair
of leaves and those of the latest formed pair. Above, the bundles
fork, connecting with the outgoing, latest formed leaf traces. In
the next stage, these bundles become surrounded by a sheath which
finally develops into a well marked endodermis. At the beginning
of each stage, there is differentiated a trace from each of the newly
formed leaves, which trace passes downward to the node below,
being there inserted in the crotch of the underlying forked bundle
which has just been developed at the close of the preceding stage.
The central bundle
The earliest sign of any medullary vascular tissue is to be
found in a single example of a fourth-stage seedling, where, in the
first epicotylar node, there are traces of medullary phloem. The
course and attachment of these medullary phloem strands (fig. 30)
are best described by starting with the conditions found just below
the node, and following these upward through the node.
As the four bundles found in the basal epicotylar internode
spread out on entering the node to form a complete ring, three
protophloem elements from the peripheral vascular tissue pass
inward toward the center. One of these protophloems arises from
ite) BOTANICAL GAZETTE [JULY
the side of one of the leaf traces of the first pair of leaves. This
single protophloem element passes inward toward the center of
the ring. It never reaches it, however, but turns upward, and
disappears in the middle of the node. The other two protophloem
elements arise, one from the side of the other leaf trace, and the
second from the adjacent face of one of the side bundles. These
pass toward the center, become applied to each other, and pass
vertically upward for a short distance; one disappears, the other
soon turns, and passes back to that side of the stem on which it
arose, becoming inserted, at the top of the node, on one of the
“forks” on the side nearest one of the descending traces of the
second pair of leaves.
In a very similar case found in a fifth-stage seedling, a single
protophloem passes off toward the center from each side of each
leaf trace. These four protophloem elements pass toward the
center and turn upward, then turning back to the ring, each fuses
with one of the descending forks, just as these enter the ring at the
top of the node. In these two cases, the medullary vascular tissue
is all entirely intranodal, there being no trace anywhere except
just within the one node.
In the fifth stage, however, there is usually developed the central
bundle of both xylem and phloem, passing from one node to the
next. There is considerable irregularity in its formation, some of
the fifth-stage seedlings being entirely without any medullary
vascular elements. Taking a seedling where the central bundle
has developed, we find, at the third node back from the apex, an
elliptical vascular ring surrounded by a well marked sheath which
usually, at this stage, does not possess any special endodermal
characters. There is no sign of any internal endodermis in this
node.
In passing downward out of this node, just as the vascular ring
breaks up into four bundles, from one edge of one of the side bundles,
a small group of phloem and xylem elements passes inward, free
from the outer ring, to the center of the pith, meeting there another
group of vascular tissue, which has broken off from the other end
of the same side bundle. At a more mature stage, the medullary
bundle may be derived from four sources, one at each end of each
of the side bundles.
1912] JONES—DIANTHERA II
At this stage, the oblique cross-arms are imbedded in the
parenchymatous tissue, there being no trace of any sheath. After
turning so as to pass vertically downward, the fused bundles become
- surrounded by a more or less well marked sheath, which soon shows
the characteristic Casparian dots on the side walls of the cells.
Just above the node below, most of the vascular elements have
died out, there being left only three or four phloem elements.
These lose their surrounding sheath, and pass across to the periph-
eral vascular bundles at a level where the endodermis surround-
ing the forks has just broken. The medullary vascular tissue
becomes applied to the outer side of one of the forks, on the opposite
side of the stem, however, from which it branched off at the node
above. Soon after this the nodal ring becomes closed. If we
examine closely the upper node, we find that the vascular elements
which turn in to form the central bundle may be traced through
the node into the forks of the side bundles of the overlying internode.
At the next stage, the central bundle is differentiated in the
next internode above in the manner just described, the lower end
of this new bundle becoming inserted at the top of the older central
bundle between the incoming cross-arms. A cambium makes its
appearance in the central bundle and cross-arms about two stages
after the differentiation of these bundles. This cambium fre-
quently forms a more or less complete ring. Usually, however, in
the seedling stages, the primary xylem and phloem crowd over to
one side of the bundle, the cambium coming in as an arc, forming a
collateral bundle of exactly the same structure as the peripheral
bundle, in spite of its entirely different origin.
The internal endodermis
In the first five stages, the endodermis which surrounds the
bundles throughout the internodes disappears from the inner faces
of the bundles on reaching the nodes, leaving only an endodermal
sheath surrounding the vascular ring in the node. From the sixth
stage on, however, it is usual for the endodermis to be continuous
through the node, both externally and internally. 3
Taking an older node as a type, we find (fig. 3), just above the
node, that every bundle is surrounded by a regular endodermal
Sheath. The leaf trace sheath is usually well differentiated only
12 BOTANICAL GAZETTE [JULY
on the abaxial side. The sheaths of the two bundles between
which the leaf trace enters soon open, the ends becoming con-
nected so as to form a complete sheath around the two bundles and
the leaf trace (fig. 4). The inner face of the sheath now bulges
toward the central bundle, finally coming in contact with it, and
breaking at the point of contact, thus forming a continuous sheath
inclosing a dumb-bell-shaped area, each head consisting of the leaf
traces and the two side bundles of the stem, the central bundle in
the middle of the connection. The endodermis on each side of
each “head” now bulges toward the remaining pair of stem bundles,
coming in contact with the endodermal sheaths of the latter, and
breaking at the point of contact.
There are thus formed three complete rings of endodermis (fig.
5), one externally surrounding the vascular ring, the other two
internal, one on each side of the transverse connecting arms.
These connecting arms very soon break, the endodermis sinking
in so as to form one sheath around the central bundle, and another
lying just internal to the vascular ring (fig. 6). This vascular ring
now breaks into four parts, the endodermis sinking in until the
external and the internal sheaths meet, then breaking apart, thus
forming the four bundles of the lower internode, each surrounded
by a complete endodermal sheath (fig. 9).
Late stage of seedling
As has been said, the seedling, by the end of the growing season,
attains a height of about 2 dm. Such a plant (fig. 31), possessing
about 20 nodes, looks very much like a plant of the “‘mature”’
type, but is smaller than the mature plant, and of course differs
in not having arisen from a rhizome. At the base, several of the
axillary buds have developed to form short, nearly horizontal
branches, the rhizomes. At the very base there is a cluster of
four strongly developed adventitious roots, nearly surrounding
the primary root, which is still less developed than the adventitious
roots. _
A histological examination shows that the vascular system has
developed in the manner already described. The uppermost pair
of leaves furnish a single trace each; these pass downward to the
1912] JONES—DIANTHERA 13
second node, where there has been formed a vascular ring. On
passing through this node, we now find a new condition. Instead
of the vascular ring breaking into four bundles, two of which fork
lower down in the internode, it breaks into four bundles, two of
which almost immediately divide, the four forks behaving in the
same way, however, as the forks produced at the lower end of the
internode of earlier stages (see diagram of path of bundles, fig. 29).
This condition is very nearly that which exists in the apex of a
mature plant (compare diagram, fig. 2), where the nodal ring
breaks up immediately into six bundles, four of which, correspond-
ing to the two forked side bundles, are usually smaller than the
other two.
An examination of the lower internodes of this stage (fig. 20),
or of the corresponding internodes of the intermediate stages,
shows that there is a tendency from the very first for the side
bundles to fork at a slightly higher level in each succeeding inter-
node. In the third stage, where these side bundles first come in,
there is but a very small amount of parenchymatous tissue inclosed
above the leaf traces by these forks, forming small leaf gaps. At
each succeeding stage, these gaps tend to be longer when formed.
I say tend, for there is considerable irregularity. One of the side
bundles may fork about the middle of the internode, while the
opposite side bundle of the same internode may not fork until very
near the bottom of the internode, or, as before mentioned, may not
even fork at all. In any individual seedling there is a gradual
transition from the immature seedling condition found in the
earliest Stages, and hence lowermost internodes, to the nearly
mature conditions found in the uppermost internodes of the
seedling at the end of the growing season.
The old seedling shows, therefore, a permanent record of its
ontogenetic development, slightly obscured, it is true, by secondary
thickening. It is comparable in this respect to a fern ‘“‘seedling,”’
the earliest formed internodes showing the simple (primitive ?)
type of structure, the later formed ones showing a gradual transition
to the mature type. It must be remembered, however, that in the
fern, when the mature structure is once formed, the main axis con-
Unues its growth, each succeeding internode having the mature
14 BOTANICAL GAZETTE [JULY
structure. In Dianthera americana, on the other hand, the main
axis seems never to produce a perfect mature type, but only
' approaches it. The mature type is here first produced in a branch,
the rhizome. When once attained, however, it is persistent, as in
the case of the fern.
Owing to the secondary development of vascular tissue, the
general appearance of the bundles, or meristeles, has changed
considerably. Instead of being strictly collateral, as they were in
the earlier stages, there is a tendency for them to become con-
centric, the xylem and phloem being formed on the sides, and later,
by the extension of the cambium, they are also formed on the inner
face of the meristeles. The cambium may even form a complete
ring, though this is not common in the seedling stages.
The presence of this internal, and of course, inversely oriented
mestome, causes the node of an older seedling to have a rather
different appearance from that of the young seedling. On entering
the node (figs. 3-9), part of the vascular tissue on the sides of the
meristeles, sometimes of the phloem only, sometimes of both xylem
and phloem, passes around to the inner face, becoming inverted
during the passage. Part of the internal mestome of two of the
bundles turns into the transverse arm, and so connects with the
central bundle. Below the transverse arm there are three con-
centric rings of endodermis, one external to the complete ring of
normally oriented xylem and phloem, the second just within the
inversely oriented mestome. The third and innermost endodermis
surrounds the central cylinder. The normally oriented mestome
is separated from the inverted vascular tissue by a layer, several
cells in thickness, of closely packed parenchymatous cells. This
layer is continuous with the parenchyma of the individual meristeles,
above and below the node. The middle endodermis is separated
from the innermost sheath by a layer of cells continuous with the
ground tissue of the internode, but much more closely packed
together. There is, however, still a considerable amount of air
space.
The epidermis and ground tissue of the late seedling are exactly
like those of the mature plant. As Hom has already accurately
described and figured these tissues, nothing more need be said of
1912] JONES—DIANTHERA 15
them. The leaves of the seedlings correspond very closely to those
of the mature plant. The latter have been fully described by
Hotm. One correction must be made, however. Hotm says
(5, p- 326) “‘collenchyma and stereome seem to be entirely absent
from the lateral portion of the blade,” apparently overlooking the _
marginal strand of collenchyma occuring in both seedling and adult
leaves (fig. 32).
The axillary buds
It has already been mentioned that buds are usually formed in
the axils of the leaves. In most cases, except at the base of the
plant, these buds, after having developed one or two pairs of very
small leaves, remain dormant. Several of the basal buds may
develop, giving rise to the horizontal rhizomes, by means of which
the plant perennates. The bud arises as a small mound of tissue
in the axil of the leaf. On this mound there soon appear the prim-
ordia of a pair of opposite leaves, whose plane of symmetry is at
Tight angles to that of the subtending leaf. A single leaf trace from
each leaf is differentiated, and passing downward becomes inserted
between the trace of the subtending leaf and an arm of the forked
bundle of the stem.
As in the main stem, the next step in development is the differ-
entiation of a pair of forked bundles, the forks of the outer bundle
being inserted between the first pair of leaf traces and the trace of
the subtending leaf. The arms of the other forked bundle become
inserted behind the first pair of leaf traces, between them and the
forks of the stem bundle. As in the stem, a pair of traces from
the second pair of leaves now differentiate, and become inserted in
the crotch at the top of the forked bundles. By this time it is seen
that a very irregular sheath is forming around each of the bundles
of the lower part of the bud (fig. 33). On entering the node below,
these sheaths open on the inside, the ends connecting so as to form
@ complete sheath surrounding the bundles of the bud and the trace
of the subtending leaf (fig. 34). Lower down, this sheath opens
on the inside, the ends connecting with those of the opening sheaths
of the “forks” of the stem. This forms a complete sheath around
all of the bundles, as is shown in fig. 35. The endodermis now
behaves in the way already described in a node which had no bud.
16 BOTANICAL GAZETTE [JULY
The later development of the axillary bud is exactly the same as
that of the main stem, with this exception: while in the stem the
transition from seedling structure to the mature type is very
gradual, the transition in the branch is much more rapid, being
completed in about 6-8 internodes. After having once been
attained, the mature type recurs constantly in each succeeding
internode.
Roots
In the old seedling there are to be found four types of roots,
each having its characteristic structure. These are the primary,
secondary, and adventitious roots, and the branches of the latter.
The primary root is diarch, maintaining this type of symmetry
even when mature. Its growing point is of the “‘Helianthus”
type, having distinct plerome and periblem initial groups, while
the calyptrogen and dermatogen have a common group of initials.
As the root matures, a cambium develops in a ring, broken opposite
the two protoxylem poles, forming two crescents of secondary
vascular tissue. The stele is surrounded by a sharply defined thin-
walled endodermis with Casparian dots. The cortex and epidermis
correspond to those of the adventitious roots of the mature plant,
sufficiently described by Horm. He, however, wrongly calls these
roots “secondary” (5, p. 319).
The true secondary roots, that is the branches from the primary
root, possess the same type of growing point as the primary root.
The symmetry varies with the age, the younger parts of these roots
being usually diarch, and becoming later tetrarch or pentarch.
The general structure of these mature secondary roots is that of
the adventitious roots. The adventitious roots, formed at the base
of the seedling, and the branches of these adventitious roots, are
exactly like those described by Horm for the mature plant. These
also possess the ‘‘ Helianthus” type of growing point.
Abnormalities in the internal structure
One very striking feature about the seedlings of Dianthera
americana is their extreme variability. Two seedlings of the same
stage, that is with the same number of leaves developed, may show
very great differences in the degree of differentiation of vascular
tissue, cambium, endodermis, etc. For instance, a seedling of the
1912] JONES—DIANTHERA 17
fifth stage may have a better developed endodermis in its basal
internode than can be found in an ordinary seedling of the eighth
or ninth stage.
One of the most striking abnormalities, however, is the failure
of an entire bundle to differentiate. This is frequently the case
with the central bundle. This may develop in one internode, fail
to do so in the next, may or may not develop in the next, and so on.
A couple of examples may be given. Counting the internodes back
from the apex, one never finds any trace of medullary vascular
tissue in the first and second internodes (the apical meristem, being
above the first node, is of course not counted). The central bundle
normally develops in the third internode, and it may be developed
in all of the nodes below this. An abnormal seedling of the ninth
stage shows the bundle developed only in the seventh internode
from the top, being entirely absent elsewhere. An abnormal
seventeenth-stage seedling (near the end of the first growing
season) shows the central bundle only in the third, fourth, fifth,
seventh, eighth, twelfth, thirteenth, and fifteenth internodes.
Abnormalities in the peripheral bundles are less common.
The failure of a side bundle to fork at the bottom of the internode
has already been mentioned. Ina single case of a mature seedling,
another type of abnormality was found. In one of the basal
’ internodes, the forks of one of the side bundles, undoubtedly normal.
in its younger state, had grown together at the base, owing to the
large amount of secondary thickening. In the upper part of the
internode there is a single bundle which forks normally, the forks
coming together, however, at the base, the endodermis disappear-
Ing between them. As the leaf trace enters, the endodermis opens
upon the outside and forms a complete sheath around the trace
and the fused bundle, the latter opening just enough to allow the
trace to be inserted between its halves.
In the basal internodes of the branches, there are usually four
Peripheral bundles. Rarely, however, one of the side bundles fails
to be differentiated.
The mature plant
At the close of the growing season, the rhizomes produced at the
base of the seedlings have developed the mature type of structure
i their younger internodes. Growth now practically ceases, the
18 BOTANICAL GAZETTE [JULY -
main axis of the seedling dying down. At the beginning of the next
growing season, the growth of the plant is continued by the
rhizomes, the apices of these turning upward as they grow, to form
the aerial shoots, each internode of which contains one central and
six peripheral bundles, each surrounded by a complete endodermis.
The development of these internodal structures is exactly that
which has been described for the seedling.
Passing back from the apex (see diagram, fig. 2), one finds at
the second node a vascular ring, which just below the node breaks
immediately into six bundles. As in the seedling, there is no differ-
entiation of a sheath in this (second) internode. In the next node,
however, a sheath appears, surrounding the vascular ring. Below
this the sheath sinks in around the six peripheral bundles. An
irregular sheath also appears around the central bundle, which
first shows in this (third) internode. The internal endodermis
passes through the next node in the manner already described in an
old node of the seedling (figs. 3-8).
A cambium develops in the pair of bundles enteriiy the stem
from the leaves in the second internode from the apex. It appears
in the side bundles in the next lower one. This cambium at first
forms an incomplete ring, but in the older internodes it is frequently
complete. The concentric structure thus produced, of pith sur-
rounded by xylem, phloem, and a stereomatic pericycle, the whole °
surrounded by a sharply differentiated endodermis, certainly justi-
fies Hoim’s statement (5, p. 309) that ‘“‘in Dianthera the steles
are very distinct and readily to be recognized as such, since they
are cylindric and possess all the necessary elements.”
The central bundle in the mature plant is plainly derived from
vascular tissue passing downward from the four side bundles (figs.
2-7). As in the seedling, it arises first in the third internode,
cambium usually showing in the fourth. The mature central
bundle, as Hoi has described, usually has the appearance of being
double, the mestome forming two arches, with parenchyma between,
the whole surrounded by a well marked endodermal sheath.
The mature type of vascular structure seems to be rather
constant. Hoim mentions that the central bundle may sometimes
be lacking, but an examination of several hundred internodes of
mature plants has failed to show such a condition. One single
1912] JONES—DIANTHERA 19
internode, lying between two normal ones, showed three medullary
bundles, the central one like the one ordinarily found, one a col-
lateral bundle surrounded by an endodermis in structure therefore
like one of the peripheral meristeles. The third, also surrounded
by an endodermis, was a strictly concentric bundle, with no paren-
chymatous tissue, the protoxylem in the center, surrounded by a
complete ring of xylem, cambium, and phloem.
The anastomosing of the bundles in the mature plant has
already been described (fig. 1). Sections show that the minute
vascular structure is very similar to that found in an old node of
the seedling. Frequently, however, there is more of the inversely
oriented vascular tissue. Some of the vascular elements on the
sides of all six of the peripheral bundles may pass around to the
inner face just before entering the node, and so become inverted.
How, in speaking of the node, says (5, p. 323) “from the union
of these steles each of the two opposite leaves receives three mestome
cylinders, readily observed in the petiole as one central, very broad,
and arch-shaped cylinder, with a much smaller one on either side.”
From the anastomosing bundles there is given off only one single
trace to each of the leaves. This single trace, however, while
passing through the cortex, gives off a branch on each side, so that
each petiole does receive the three bundles as described by Hox.
This giving off of a single leaf trace, which trifurcates while yet in
the cortex, is, according to VAN TreGHEM (11), the conformation
found in all of the Acanthaceae. It should be noted, however, that
DeBary (3, Pp. 243), in speaking of the course of the bundles in the
stem, places Ruellia maculata in the group described as having “leaves
Opposite: traces of three or four bundles, which unite at the second
lower node with those of the next lower pair: not pectinated.”
The leaves of the aerial shoot have already been fully described
by Horm. Instructure they are identical with those of the seedling,
hence the correction concerning the presence of the marginal strand
of collenchyma in the blade has to be made here also.
The axillary buds of the mature plant
As in the seedling, a bud is usually formed in the axil of each
eaf. Those at the base of the aerial shoot usually develop into
thizomes, or moré rarely into vertical aerial branches. In either
20 BOTANICAL GAZETTE [JULY
case, the development is exactly the same as in the buds of the
seedling, having therefore an astelic structure. Each internode
has six peripheral and one central bundle, except the basal, in
which the central bundle may or may not be differentiated.
The buds of the upper part of the plant, on the other hand,
ordinarily develop into inflorescence axes. As Hom has pointed
out, these have a monostelic structure (fig. 36). These buds start
their development in the same way as do the buds which develop
the rhizomes and stem branches. The first pair of leaves, or rather
bracts, first furnish a pair of traces, then the pair of forked bundles
develop; the second pair of bracts supply a pair of traces, exactly
as in the other kind of bud. The connections of these bundles with
each other and with those of the stem on which they are inserted
are also as in the branch bud. The pedicel of the single flower
developed in the axil of each bract possesses a ring of vascular
tissue. At the base this ring splits on the face nearest the bract
on one side, and nearest the inflorescence axis on the other. The
two halves so produced become inserted between the bract trace
and the forked bundle of the inflorescence axis.
The difference between the structure of the inflorescence axis
buds and those forming ordinary branches soon becomes visible.
One difference is the greater length of the internodes of the latter-
The most important difference between them, however, lies in the
fact that in the inflorescence axis, the inner layer of the cortex,
while forming a rather irregular sheath around the stele, apparently ~
never forms a strongly developed endodermis. This sheath, on
passing out of a node, never sinks in between the bundles, but
remains as a ring, marking the boundary, rather indistinct at
times, between the cortex and the central cylinder. The paren-
chymatous tissue of the latter differs from that of the former in
being made up of larger cells, and in containing a very much ~
smaller proportion of air space. The general appearance of a cross-
section is very similar to a monostelic stem in which the individual
bundles tend to remain separate.
Let us now compare the insertion of a well developed branch
with that of an inflorescence axis. Taking a case where the basal
internode has no central bundle, we find that the trace of the sub-
tending leaf enters between the abaxial side bundles of the branch.
Igt2] JONES—DIANTHERA 21
The endodermal sheaths of the six branch bundles open up, each
connecting with that of the adjacent bundles, so as to form a
complete sheath around the leaf trace and the six branch bundles
(figs. 33-35). Where the central bundle is present, a connection
is made between the two pairs of side bundles and the central
bundle, all of the vascular tissue of the latter passing to the periph-
ery and becoming normally oriented. Then the ring of the six
peripheral bundles and the incoming leaf trace become surrounded
as before by a common sheath (figs. 37-41).
In the case of the inflorescence axis, the vascular ring shows a
tendency to break up into six bundles. This ring opens on the side
to allow the entrance of the leaf trace, or rather bract trace; the
sheath then surrounds the ring and the trace (figs. 42-45). The
structure so produced is in cross-section almost identical with that
produced by the branch. The further history is the same for
both types.
The organogeny of the flower
The apex of the inflorescence axis continues its activity all
through the flowering season, giving rise to opposite, decussate
bracts, in the axils of which are produced the flowers. The greatest
growth of the inflorescence axis is due to intercalary activity in
the basal internode.
In the axil of each developing bract a slight mound develops.
On this mound, which is to be the flower, there appear first of all,
apparently synchronously, the five sepals (fig. 46), followed very
soon by the five petals. At first the latter are separate, but soon
coalesce to form the corolla tube. About the same time that the
corolla is initiated, two large mounds appear, marking the primordia
of the stamens (figs. 47 and 48). There is never any trace of more
than two stamens (five occur in some of the Acanthaceae, in other
genera there are two stamens and three staminodia). The ovary
rows up as a ring (fig. 49), the sides nearest and farthest from the
axis of the plant being slightly (10-15 #) higher (fig. 50). The petals
soon coalesce, the stamens being carried up on the corolla tube.
The ovarian “ring”’ closes in over the top and continues its growth
to form the pistil with its deeply two-lobed stigma. The placentae
§row out from the opposite walls of the ovary, near its base. Two
ovules arise on each placenta. The two placentae now gradually
22 BOTANICAL GAZETTE [JULY
grow together, dividing the ovary into two cells. One ovule from
each placenta is left in each cell.
The vascular supply of the floral organs
In the pedicel of a mature flower is to be found a complete ring
of vascular tissue. Above this ring breaks up into 26 bundles, three
of which pass out to each of the five sepals, five bundles passing
up into the tube of the corolla, two large concentric bundles supply
the stamens, and four pass up into the ovary. Two of the latter
bundles, lying in the sagittal plane of the flower, pass up the car-
pellary walls, each giving off two laterals. The laterals die off
near the top of the carpel, the medians however passing out into
the style, which therefore possesses two bundles. The two remain-
ing carpellary bundles branch, each giving off a bundle which
supplies the placental wall. The other arm of each forks, the
bundles so produced passing up the side walls of the carpel until
near the top, where they disappear. Each of the five bundles
passing out into the tube of the corolla gives off several branches
while passing through the tube. Each of the stamen bundles pass
up between two of the bundles of the corolla, being sharply dis-
tinguished from them in being concentric instead of collateral.
They pass out into the stamens when the latter become free from
the corolla tube.
As we pass down the short pedicel to its insertion, we find the
ring first opens on the inner face (figs. 51 and 52). The inflorescence
axis shows two large flat bundles, each of which now forks (figs. 51
and 52), each of the arms becoming applied to the sides of the
opened ring from the pedicel (fig. 53). These two vascular
masses then divide to allow the entrance of the single bract trace.
The two vascular bundles now tend to round up (fig. 54). In the
basal internode this division into two parts is not so marked, as the
endodermal sheath usually forms a complete ring around the
vascular tissue (fig. 36).
Discussion
According to Hoi, some of the species of Dianthera which he
examined were monostelic. These were D. comata L., D. glabra
B. & H., D. inserta Brandg., D. ovata Walt., D. parvifolia B. & H.,
1g12] JONES—DIANTHERA 23
D. pecioralis Murr., and D. sessilis Gray. I was unable to obtain
any of these species for comparison. I did obtain seeds, however,
of the fairly closely related Justicia ventricosa. A few of these
germinated, and I was able to study a few of the seedling stages.
The germination is similar to that described for Dianthera ameri-
cana. Likewise are the first three stages. After that, the
interfascicular cambium masks the primary structure.
Comparing this then with Dianthera americana, we find that
they are at first exactly the same. The first point of difference is
the failure of the interfascicular cambium to appear. This leaves
the bundles separate, around which the endodermis turns in and
surrounds, instead of remaining as a complete ring, as in Justicia.
In the mature plant, we find that the first two apical nodes of
Dianthera americana are similar to other acanthaceous plants
(Justicia, Fittonia, etc.). In the latter, the traces of the first pair
of leaves pass down to a ring of vascular tissue. Below this node
there are two arcs of tissue, each of which is evidently of three
parts, showing three widely separated protoxylems. This inter-
node, therefore, has a structure exactly like that of a young inter-
node of the inflorescence axis of Dianthera americana. At the next
node the opposite leaf traces enter between the two arcs. Below
this node the original structure cannot well be made out, owing to
secondary thickening.
It is evident that the seedling and the inflorescence axis of
Dianthera americana show the primitive condition of the group,
and that the formation of endodermal sheaths around each of the
Separate bundles, that is, the condition of astely, is a secondary
condition, found only in a part of the species of Dianthera (accord-
ing to Howm, D. crassifolia Chapm. and D. lanceolata Small, are
also “‘polystelic”’). :
Although astely apparently has not been previously described
aS occurring in the Acanthaceae, yet many other vascular abnor-
malities are known. The interxylary phloem of Thunbergia and
others is well known. Intraxylary phloem (Thunbergia, Hexacen-
tris, Barleria, etc.), medullary phloem (petiole of Acanthus mollis),
and even medullary bundles (Acanthus spinosus, etc.), have also
been described. It is thus seen that the family shows irregulari-
Hes of vascular structure.
24 BOTANICAL GAZETTE [JULY
In Dianthera americana, the two chief types of abnormality
found in the family occur, that is, the astelic condition and the
medullary vascular tissue. The former is evidently not in any
way dependent on the latter, since in the seedling the plant is —
frequently astelic when there is no medullary tissue developed.
In the terms of the stelar theory, Dianthera americana in its
early stages is monostelic. In the young seedling the first endo-
dermis differentiated, surrounding the nodal ring, corresponds to
the inner layer of the cortex. The stem apex is rather broad and
flat, but the three histogen layers of HANSTEIN can usually be made
out. From the plerome is developed a central cylinder, all that is
within the endodermis. The parenchyma of this stele corresponds,
therefore, to pith and medullary rays.
This seems clear enough in the early stages of Dianthera and
also in Justicia. In the latter this condition persists permanently;
there is always a well marked cortex and central cylinder, with its
pith. In the internode of. Dianthera americana, on the other hand,
an endodermal sheath about each bundle is initiated, passing
around the bundle and inclosing on the inner face of the latter a
mass of parenchyma. From our previous interpretation, this
endodermis differentiates on the sides of the bundles from the
parenchymatous cells of the medullary rays, and on the inner face
from the pith itself. In such a case the endodermis surely cannot
correspond with any morphological layer.
Now let us examine the fate of the parenchyma of the original
central cylinder, that is, that derived from the plerome. That part
which is inclosed within the endodermal sheath undergoes little
change, while that outside the sheath gradually becomes so modified
as to appear exactly the same as the cortical tissue. At this
mature stage, then, there is no visible differentiation between the
cortex and the pith, except within the endodermis. And yet we
have seen that they had an entirely different origin, the one derived
from the plerome, the other from the periblem. Unless one leaves
out of account the different origin, and compares only the mature
structures, one is certainly not justified in saying in this case, as
Van TiecGHEM and Dutiot (12, p. 275) say in their definition of
astely, that the bundles are “directement plongés dans la masse
s
1912] JONES—DIANTHERA 25:
générale du corps qui ne se séparé pas alors en écorce et conjonctif”’
(p. 275).
STRASBURGER (Q) distinguishes between the inner layer of the
cortex, which is a morphological layer, and the endodermis, which
is merely ‘“‘an air-tight barrier which does not prevent the passage
of water through its cells. Such a layer is found in a position to
shut off the water-conducting system of a plant from its air-
containing lacunar system, but this position may vary within the
same genus, and has no necessary connection with any morphologi-
cal region” (quotation from TANSLEY 10).
According to this interpretation of the endodermis, which is
therefore merely a physiological layer, astely is merely a modifica-
tion of monostely. This is the view already taken by STRASBURGER
(9); the same idea is presented in a recent paper by GREGOIRE (4).
The parenchyma of the central cylinder, that is, outside of the
endodermis, becomes different from that inclosed within the sheath,
owing to the different physiological environment, and it becomes,
like the cortical tissue, a response to the same physiological
conditions.
If we leave out of account for the present the surrounding endo-
dermis, we see that the medullary system of Dianthera americana
corresponds to what Cor (1), in his work on the arrangement of
bundles, calls “série M’.” He defines this type as follows (p.
242): “faisceaux normaux rentrant dans la moelle de la tige. Ils
s’accolent inférieurement A d’autres faisceaux medullaires, et tous
ceux des entre-nceuds les plus inférieure de la tige se poursuivent
€t se terminent isolément dans la racine (dans le bois) ou a la base
de la tige.”
WEIss (14) has shown that all medullary bundles of the stem
are foliar bundles. The work of LicNrER (7), Krucu (6), and Cot
(1, 2) fully confirms this. In Dianthera americana it is easy to
follow the leaf trace downward through two internodes, and to see
that a part then turns inward to form the medullary vascular
tissue.
In a paper describing for the first time the medullary bundles of
Acanthus Spinosus, VESQUE (13) says that he thinks the primary
effect of the internal position of the phloem is its very efficacious
26 BOTANICAL GAZETTE [JULY
protection. He calls attention to its common occurrence in lianes
and in creeping plants, and says that the protection counter-
balances the danger to the phloem due to the great length and
weakness of the stem.
Cox (2), on the other hand, presents the following hypothesis
(translated from p. 275): ‘‘The histological structure of the con-
ductive tissues does not permit a sufficient condensation to form a
single circle. The wood becomes condensed, more easily than the
phloem, into a small bundle; without doubt on account of the
fluidity of the ascending sap, and of the easy passage of liquids
from one vessel to another. For converse reasons, the phloem is
less capable of becoming condensed.”’ When two bundles come
together, therefore, the phloem passes around the sides of the wood
to the inner face, or it may even become medullary. While it is
undoubtedly true that the phloem is better protected in its internal
position, as suggested by VESQUE, yet from my observations on
Dianthera americana, it would seem that the hypothesis of CoL
certainly holds in that plant.
It may be that, in this case, the internal vascular tissue is cor-
related with the lack of a complete ring of vascular tissue. The
phloem, not finding sufficient room on the outer face of the indi-
vidual bundles, becomes crowded around to the sides, or even to
the inner face of the bundles. The new vascular tissue descending
from the uppermost leaves does not find room for its insertion, so
part of it at least passes inward to form the central bundle. After
it has begun its development imbedded in the pith, a sheath finally
differentiates to separate it from the air-containing tissue of the
much modified mature pith.
As to the cause of the astelic conditions found in this and other
species of Dianthera, very little can be said. It is probably cor-
related, however, with the aquatic habitat. The large amount of
air space undoubtedly is to be correlated with the aquatic habitat.
If we agree that the endodermis is not a morphological boundary,
but a physiological layer separating the vascular tissue from the
“air-containing lacunar system,’”’ as claimed by STRASBURGER,
then we have a simple, plausible explanation of this phenomenon.
More comparative work on this and other species of Dianthera
1912] JONES—DIANTHERA 27
is needed, however, especially to find out if possible the physiologi-
cal value of the endodermis. Possibly such work would lead to
the discovery of the reason why some species of this genus are
monostelic, and apparently normal in every way, while other
species are abnormal in being astelic, and in possessing medullary
vascular tissue.
Summary
The mature plant of Dianthera americana is astelic, instead _
of polystelic, as claimed by Horm. It possesses six peripheral
meristeles and one central medullary bundle, each completely sur-
rounded by an endodermal sheath. At the nodes these anastomose.
The seedling is at first monostelic; the individual bundles
gradually become surrounded by the endodermal sheaths.
The mature type of structure with six bundles is derived from
the seedling type with only four, by the increase of the size of the
leaf gaps.
The inflorescence axis is monostelic.
Dianthera americana differs from related forms in the lack of
interfascicular cambium, the individual bundles becoming sur-
rounded by endodermis. Its medullary bundle is quite com-
parable to the medullary bundles of Acanthus spinosus, many
Campanulaceae, and other plants.
It is probable that astely is merely a phase of monostely, the
endodermis being a physiological layer, the medullary and cortical
parenchyma becoming similar owing to like physiological conditions.
Astely in this plant is probably correlated with its aquatic
habitat.
Jouns Hopxins UNIVERSITY
Battimore, Mp.
LITERATURE CITED
t. Cot, A., Relation des faisceaux medullaires avec les faisceaux normaux.
Journ. Botanique 16: 234. 1902.
ae Recherches sur la disposition des faisceaux dans la tige et les
feuilles de quelques dicotylédones. Ann. Sci. Nat. Bot. VIII. 20:1. 1904.
3- DeBary, A., A comparative anatomy of the phanerogams and ferns.
English translation. Oxford. 1884.
sf Grécore, V., La valeur de la couche amylifére dans la tige, et la théorie
stélaire de Van TircHem. Ann. Soc. Sci. Bruxelles 345-12. t910.
2.
28 BOTANICAL GAZETTE [JULY
5. Horm, THEo., Ruellia and Dianthera; an anatomical study. Bor. Gaz.
43:308. 1907.
6. Krucu, O., Fasci midoll. d. Cichoriacees. Ann. R. Inst. Bot. Roma. 1890.
7. LIGNIER, O., Anatomie des Calycanthées, des Melastomacées, et des
Myrtacées. Diss. Paris. 188
8. ScHAFFNIT, Ernst, Beitriige zur Anatomie der Acanthaceen-Samen. Inaug.
iss. Leipzig. 1905.
9. STRASBURGER, E., Ueber den Bau und Verrichtung der Leitungsbahnen.
Hist. Beitr. 3: Tins: 1891.
“10. Tanstey, A. G., The stelar theory; a history and a criticism. Science
Progress 5: 133. 180 6.
11. VAN TIEGHEM, Pu., Relation entre la production des cystolithes et la con-
formation de la région stélique du clasts dans la nouvelle famille des
Acanthacées. Journ. Botanique 21:25.
12. VAN TIEGHEM et Dovutiort, Sur la pained. Ann. Sci. Nat. Bot. VII.
45276. 1580:
13. VESQUE, J., Mémoire sur l’anatomie comparée de l’écorce. Ann. Sci. Nat.
Bot. Vi. 2:82. 1875.
14. Wetss, J. E., Das markstindige Gefissbiindelsystem in seiner Beziehung
zu den Blattspuren. Bot. Centralbl. 15: 401-415. 1883.
EXPLANATION OF PLATES I-IV
All drawings of sections were made by means of a camera lucida. In the
diagrams, xylem is represented by cross-hatching, phloem by dots. In figs.
3-9 the endodermis is represented by cells. The index letters are as follows:
A.R., adventitious root; B, bract; BR, branch; BR.T., branch trace; C;
carpel; C.B. central bundle; CL, calyx; COT, cotyledon; CR, corolla; END,
endodermis; EP, epidecudie: ESP, endosperm; [.A., inflorescence axis; L,
leaf; L.T., leaf trace; M.PH., medullary phloem; P.B. peripheral bundle;
PC, procambium; PPH, caceisobiioean: P.R., primary root; PX, protoxylem;
S,stamen; ST,stem; 7, testa; T.A., transverse arm.
PLATE I
Fic. 1.—Reconstruction of the vascular system of two adjacent mature
nodes.
Fic. 2.—Diagram of the paths of the peripheral bundles of a mature stem.
Fics. 3-8.—Series of successive transverse sections through a mature node,
passing from fig. 3, made just at the top of the node, to fig. 8, made just below
the node; X45.
1G. 9.—Transverse section through the upper part of an internode of an
old ceding showing one central and four peripheral bundles; X45.
1G. 10.—Part of a sagittal section of a seed, directly opposite the micro-
pyle, sivwina the testa with its thickened epidermal cells, and the endosperm
of two layers; 185.
1912] JONES—DIANTHERA 29
Fic. 11.—Sagittal section of a seed; X12.5.
Fic. 12.—Longitudinal section of a seed, made perpendicular to the plane
of the section shown in fig. 11, and through the line mn; X12.5.
PLATE II
Fic. 13.—Transverse section of the upper part of the hypocotyl of a ripe
seed, ee below the insertion of the cotyledons; x 185.
G. 14.—Transverse section through the middle portion of he same
Neraeat showing the periclinal division of the endodermis on either side of
the stele; 18s.
Fic. 15.—Habit sketch of a seedling; stage I, with cotyledons still inclosed
within the testa; Xr. s.
Fic. 16. Sete piaae section of the upper portion of a first-stage seedling
just below the insertion of the cotyledons, showing the two “double” weve:
donary traces; X 185.
Fic. 17.—Diagram of the paths of the bundles in a seedling, stage I.
Fic. 18.—Diagram of the paths of the bundles in a seedling, early phase
of stage IT.
Fic. 19.—Habit sketch of a seedling, stage II (late phase); Xt.
Fic. 20.—Diagram of the paths of the bundles in a seedling, late phase of
Stage IT.
Fic. 21.—Diagram of the paths of the bundles in a seedling, early phase of
Stage ITT.
Fic. 22.—Habit sketch of a seedling, stage III; X1.
IG. 23.—Transverse section of one of the side bundles in the basal epi-
cotylar internode of a third-stage seedling, showing its “double” appearance,
the est Lovee aie and three protophloem elements; X 380.
24.—Transverse section of the same bundle as shown in fig. 23, at a
lower leva just at the top of the fork; 380.
25.—Transverse section of ae same bundle still lower down, the
oki complete; X 380.
Fic. 26.—Surface view of a glandular hair; 380
Fic. 27 -—Longitudinal section of a glandular ‘halt and _ neighboring
epidermis; > 380.
1G. 28.—Transverse section of the uppermost internode of a third-stage
seedling, showing the two procambial bundles . the traces of the uppermost
pair . see imbedded in the ground meristem; X 380.
G. 29.—Diagram of the paths of the abe bundles in a seventeenth-
Stage fending (near end of growing season), showing the gradual development
of the “mature” type by the increase in length of the leaf gaps.
PLATE III
Fic. 30.—Restoration of the vascular system of a node of a fourth-stage
Seedling, showing the courses and attachments of the intranodal medullary
Phloem strands.
*
Oe,
30 BOTANICAL GAZETTE [JULY
Fic. 31.—Habit sketch of an old seedling (stage XVID), near end of grow-
ing season, showing the development of rhizomes from the basal axillary buds;
Xo. 5.
Fic. 32.—Transverse section of the margin of the blade of a mature leaf,
showing the collenchymatous strand; X 210.
Fics. 33-35.—Series of successive transverse sections through the upper
part of a node, showing the insertion of a branch which has no central bundle
developed in its basal internode. :
Fic. 36.—Transverse section of the stele of the basal internode of a mature
inflorescence axis;
Fics. 37-41.—Series of successive transverse sections through the upper
part of a node, showing the insertion of a branch in which the central bundle
has developed in the basal internode.
PLATE IV
Fics. 42—45.—Series of successive transverse sections through the upper
part of a node, showing the insertion of an inflorescence axis; X 50.
Fic. 46.—Longitudinal section through the apex of an inflorescence axis,
showing the origin of the opposite bracts, the axillary flowers, and the primordia
of the calyx on the lower flowers; X 50.
Fic. 47.—Longitudinal section of a young flower, not quite median,
showing the bract, calyx, corolla, one of the stamens, and the edge of carpel;
oO.
Fic. 48.—Longitudinal section of a young flower, made perpendicular to
that shown in fig. 47, iss the line mn, showing the two large stamens free
from the corolla;
IG. 49. Saat section of a slightly older flower, showing the formation
of the ovarian cavity; X50.
Fic. 50.—Transverse section (very slightly oblique) of a flower of about
the same age as that shown in fig. 49, showing the arrangement of the floral
parts, and the two lobes of the carpels; X 50.
Fics. 51-54.—Series of successive transverse sections through a node of
an inflorescence axis, showing the insertion of the bundles of the opposite
pedicels and bracts with those of the main axis; 22.5.
PLATE I
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PLATE Ill
BOTANICAL GAZETTE, LIV
JONES on DIANTHERA
DIANTHERA
JONES on
THE TOXIC ACTION OF ORGANIC COMPOUNDS AS
MODIFIED BY FERTILIZER SALTS*=
OSWALD SCHREINER AND J. J. SKINNER
(WITH FIVE FIGURES)
In a former paper? the results obtained with dihydroxystearic
acid, a crystalline organic compound isolated from a number of
unproductive soils, was presented. The results obtained with this
organic soil constituent, showing its effect on growth and absorp-
tion of plant nutrients from the various culture solutions containing °
a wide range of fertilizer composition, showed the desirability of
obtaining further information concerning the behavior of other
organic bodies known to be harmful to plants.
In the present paper some of the results obtained in experiments
with toxic organic substances and the restraining influence on their
toxicity by fertilizer mixtures of different composition will be given.
The compounds studied, though not actually isolated from soil, '
are common constituents of plant débris, or result from this through
changes, and so become, at least temporarily, components of the
soil. The effects of a large number of such compounds on plant
growth was given in an earlier paper. Of these compounds,
cumarin was selected for the continuation of these researches
because it was quite harmful even in minute amounts, a few parts
per million of solution having a noticeable effect on plant growth,
and because it was a common constituent of a number of plants
the remains of which get into the soil.
The earlier results were obtained in solutions of the cumarin in
distilled water. The present investigation concerns itself with
the effect of cumarin in the presence of nutrient salts as well, the
*Published by permission of the Secretary of Agriculture, from the Laboratory
of Fertility Investigations.
ScHREINER, O., and SKINNER, J. J., Some effects of a harmful organic soil con-
Stituent. Bor. Gaz. 50:161. 1910.
and Reep, H. S., The toxic action of certain organic plant
SCHREINER, O.,
constituents. hint Gaz. 45°73, 7%. 1908.
31 [Botanical Gazette, vol. 54
32 BOTANICAL GAZETTE [JULY
essential constituents of these being present to the extent of 80
ppm., but the composition varies. The number of culture solu-
tions of the fertilizer salts used was 66, this being the number
requisite to obtain every possible ratio of P,O;, NH;, and K.O, in
Io per cent stages. The system employed, as well as all details
of preparation, was the same as already described in the similar
investigation with dihydroxystearic acid already mentioned.
POs
i]
AK
QOD
ONAN
LELDLDESOO
LTILAAAT
x 2° a NH
Fic. 1.—Showing the triangular diagram, with the points numbered, which
represent the 66 culture solutions.
The triangular diagram is used as a guide. In this diagram
(fig. 1), the apices, nos. 1, 56, and 66, are the cultures which con-
tain only the single salts, calcium acid phosphate, sodium nitrate,
and potassium sulphate, respectively; that is, the total of 80 ppm.
contains roo per cent of P,O;, NH;, or K,O, respectively. The line
of cultures between 1 and 66 contains mixtures of P,O, and NH;
in 10 per cent differences; the line of cultures between 1 and 56 —
1912] SCHREINER & SKINNER—FERTILIZER SALTS 33
contains mixtures of P,O, and K,O in 10 per cent differences; the
line of cultures between 56 and 66 contains mixtures of K,O and
NH. The cultures in the interior of the triangle contain mixtures
of all constituents, differing in 10 per cent stages one from the other,
the composition depending upon its position in the triangle; those
nearer the P,O,; apex consisting chiefly of phosphate fertilizer,
those nearer the NH, apex chiefly of nitrate fertilizer, and those
nearer to the K,O apex chiefly of potash fertilizer. For a more
detailed explanation of the scheme and principles involved, the
reader is referred to an earlier paper.*
Two sets of these 66 culture solutions were prepared, one of
them containing in every culture 10 ppm. of cumarin. The total
concentration of the nutrient elements P,O,+NH,+K;.0 was in
all cases 80 ppm. The culture solutions were contained in wide-
mouth bottles and 10 wheat seedlings grown in each culture after
the manner described in the paper cited. The culture- solutions
were changed every three days, four such changes being made in
each experiment. The culture solutions were analyzed imme-
diately after each change for nitrates, but the phosphate and
potassium were determined on a composite of the four changes.
The green weight of the plants was determined at the termination
of the experiment. The first experiment with cumarin was set
up on December 9 and discontinued December 21.
The effect of even so low a concentration as 10 ppm. of cumarin
was strikingly noticeable in the difference between the plants grow-
ing in the two sets of cultures. The appearance of plants growing
in solutions containing cumarin is very characteristic and totally
different from the effect on wheat of any other toxic compound
worked with in this laboratory. The leaves are shorter and broader
than is normal for wheat, and only the first leaves are usually
unfolded, the other leaves remaining wholly or partially within the
swollen sheath; such leaves as do break forth are usually distorted
and curled or twisted. The appearance is so characteristic that
the investigator can pick out the cumarin-affected plants from
those affected by any other toxic body in the same experiment by
i INER, O., and SKINNER, J. J., Ratio of phosphate, nitrate, and potassium
on absorption and growth. Bort. Gaz. 50:1. 1910.
34 BOTANICAL GAZETTE [JULY
a mere glance. This characteristic behavior of cumarin-affected
plants becomes, therefore, in addition to the usual criteria, an
indicator of the degree of its harmfulness in the cultures of different
composition in this experiment. In addition to its effect on the
tops, as just described, there was a general inhibition of root growth,
as is the case with many other substances, notably the dihydroxy- —
stearic acid already described.
The effect of the cumarin was to depress the green weight of
the plants from 100 to 88 as an average in this experiment, although
it was obvious from the appearance of the cultures that its effect
was far from uniform in all of the cultures, and this is the most
interesting feature of the experiment.
It will be recalled that with dihydroxystearic acid the more
normal growth was observed in the nitrogen end of the triangle,
but when the cumarin cultures were set out in this triangular form
according to the composition of the culture solutions, it became
at once apparent that the result with the cumarin was not in har-
mony with the observation so repeatedly made with the dihy-
droxystearic acid. It was clear that the cumarin had an entirely
different effect in the different culture solutions from that observed
in the case of dihydroxystearic acid, which had responded most in
the fertilizer combinations high in nitrate. With the cumarin
the growth was more nearly normal in the fertilizer combinations
high in phosphate. In comparing the cultures, those of like
composition only are compared in the cumarin and in the normal
sets.
This influence of the phosphate on the harmful effect of the
cumarin is perhaps most strikingly shown in the difference between
the plants growing in the culture solution containing no phosphate
whatever, namely along the line 56 to 66 in fig. 1, and the line of
cultures immediately above this, containing ro per cent phosphate
in the fertilizer mixture. Where phosphate is entirely absent, the
effect of the cumarin is most marked. Above this line the harm- —
ful effect of the cumarin steadily decreases, and in the upper part
of the triangle disappears altogether, so far as the eye can detect
this in the appearance of the plants in the normal and cumarin set.
The effect of the phosphate in overcoming the harmful action
TQ12] SCHREINER & SKINNER—FERTILIZER SALTS 35
of the cumarin is shown in the green weight of the plants taken at
the termination of the experiment. In table I is given the green
weight of the series of cultures containing the same amount of
Phosphate; that is, the series along any one of the horizontal lines
in fig. r.
TABLE I
SHOWING THE INFLUENCE OF PHOSPHATE IN OVERCOMING THE HARMFUL EFFECT OF
UMARIN
. P GREEN WEIGHT OF CULTURES
ARTS PER MIL-
geil LION OF P.O; crane ted cule
wn moncmat | Sreuvpen | Without | With _| Relative (with
cumarin cumarin =100)
° ° II 21.773 15.370 vie)
to 8 Io 22.408 18.835 84
so 16 9 20.339 17.140 84
3° 24 8 7442 15.350
te 32 7 15.008 14.085 04
59° 40 6 11.188 II.150 100
60 48 5 9-113 9.005
79 56 4 6.915 6.485 04
80 64 3 4.171 4.330 104
90 WEG 2 2.388 2.530 106
Too 80 I 0.932 0.955 102
The last column of the table gives the relative growth between
the two sets of cultures, with and without cumarin. It will be
seen from the last column of the table that in those cultures in
which no phosphate was present the depression in growth caused
by cumarin was greatest, being reduced to 70 per cent of the normal,
and that the introduction of 8 ppm. of phosphate caused the growth
to rise to 84 per cent of the normal. On further increasing the
Phosphate content to 16, 24, 32, and 40 ppm., the green weight
Tose to 84, 90, 94, and too per cent of the normal, respectively.
From this point on the growth is practically as good in the cumarin
Set as in the normal control set, thus showing that, on the whole,
the fertilizer combinations high in phosphate were practically able
to overcome the harmful influence of the toxic cumarin.
__ The lessened toxicity of cumarin in solutions high in phosphate
1s also shown when the results of the experiment are grouped in
such a way as to obtain all cultures containing 50 per cent and over
of any one of the three constituents, P,O;, NH;, and K,O, as was
36 BOTANICAL GAZETTE [JULY
done in the case of the dihydroxystearic acid experiment. This
is accomplished by taking the cultures contained in the smaller
triangles formed at each angle of the larger one shown in fig. 1;
that is, the cultures contained within the triangles 1, 16, 21; 21,
61, 66; and 16, 56, 61, respectively. The sum of the green weights
in these respective triangles is shown in fig. 2 for the normal and
the cumarin sets, together with the relative growth. The phosphate
P2O5
—— oo
=
Fic. 2.—Showing the relative growth of normal and cumarin cultures in solutions
high in phosphate, nitrate, or potash, respectively.
end shows that the growth in the cumarin set was nearly normal
99 per cent, whereas the potash and the nitrogen end showed a
growth only 83 per cent of the normal. :
A second set of experiments with cumarin was made and was 1n
all respects conducted as in the first experiment. This grew from
January 12 to January 24. 7 :
The cumarin-affected plants showed the same characteristic
stunting of the leaves as in the former experiment, and, moreover,
.
1912] SCHREINER & SKINNER—FERTILIZER SALTS 37
again showed strikingly the influence of phosphate in overcoming
this effect, the general appearance of the entire triangle of cultures
being similar to that already described. The effect of the cumarin
was to depress the green weight from 100 to 75 in this second
experiment, this being the average depression for all the cultures
in the set. Here, as in the first experiment, the toxicity of the
cumarin was lessened most in the solutions high in phosphate,
being 85 per cent of the normal as compared with 74 and 70 per
cent in the cultures high in nitrate and potash, respectively.
The line of cultures containing no phosphate whatsoever again
showed the greatest effect of the cumarin; this harmful influence
becoming less and less until complete recovery of the plants is
noticed in the cultures containing higher amounts of phosphate.
The total absence of phosphate showed a depressed growth equal
to 62 per cent of the normal; this rises to 70 per cent on the addi-
tion of 8 ppm., and to 76 per cent on the addition of 16 ppm., and
so on upward, somewhat irregularly but definitely, until in the higher
concentration of phosphate the effect of the cumarin is lost entirely.
The foregoing experiments show clearly the influence of cumarin
on growth and the effect of phosphate in counteracting the harmful
influence of the cumarin. There remains to be considered the in-
fluence of the cumarin on the concentration of the solution during
the growth of the plant.
Mention has already been made of the fact that the concen-
tration differences produced by the growth of the plants in the
various cultures was determined by making an analysis for nitrate
at the termination of every three-day change, and of the phosphate
and potassium on a composite of the solutions from the four
changes. It is thus possible to compare the results obtained under
the so-called normal conditions without the cumarin and under the
conditions where ro ppm. of cumarin were present in the solution.
The 36 cultures comprising the fertilizer combinations in which
all three fertilizer elements are present were consistently analyzed
and these only are here considered.
The amount of total P,O,+NH;+K.0 removed from solution
by the growing plants in the total number of 36 cultures was 1379
milligrams under the normal conditions and 1272 milligrams in
38 BOTANICAL GAZETTE [JULY
the cumarin set. In table II are given the results for the P.O,,
NH,, and K,0O, peparately, under the normal conditions and in the
cumarin set.
TABLE II
TOTAL MILLIGRAMS OF P.0;, NH;, AND Kx0 REMOVED FROM THE 36 CULTURE SOLUTIONS
CONTAINING ALL THREE OF THESE INGREDIENTS
Htorat ABSORPTION IN MILLIGRAMS| PERCENTAGE OF
RELATIVE CUMARIN CULTURES
| Normal Cumarin a ee
PA ee ee 278.5 264.5 95 57
Wii ois aa 482.6 405 3. 86 22
j A a eae nae 618.2 592.6 96 39
An examination of these figures discloses the fact at once that
while the cumarin has decreased the absorption of these nutrient
elements, it has not decreased it anywhere near the extent shown
by dihydroxystearic acid in the experiment cited. The third
column of figures gives the relative effect of cumarin absorption
of each nutrient element, and indicates that the phosphate and
potash absorptions were the more nearly normal of the three,
especially the phosphate absorption if the figures in the last column
are taken into account. This column gives the percentages of the
individual cumarin cultures which showed an absorption equal to
or greater than the corresponding culture without cumarin.
In the second experiment this effect is clearly marked, the phos-
phate absorption being gr per cent of the normal, as compared with
78 and 87 for the nitrate and potash, respectively. In this experi-
ment the total absorption of P,O,+NH,;+K,0 was 1267 milli-
grams under normal conditions and 1077 milligrams with cumarin.
While these figures indicate a somewhat more normal phosphate
absorption in the cumarin set than normal nitrate or normal potash
absorption, the figures are, nevertheless, not decisive enough to
enable one to say definitely that the antagonism of the phosphate
to cumarin, as shown in the growth of the plants, is due to this
cause alone. A rigid examination of the complete data does not
allow us to draw this conclusion without at the same time suggest-
ing the possibility of an external interaction between the lactone
1912] SCHREINER & SKINNER—FERTILIZER SALTS 39
cumarin and the acid calcium phosphate. The possible solutions
of the problem must be left for future investigation.
From the foregoing results it is apparent that the two toxic
substances studied, dihydroxystearic acid and cumarin, show
markedly different physiological properties, and are very differently
influenced by fertilizer salts. Whether this is a direct action of the
fertilizer on the organic body or through the medium of the plant
cells, making the toxic substance and the particular fertilizer salt
physiologically antagonistic, cannot be definitely stated.
The cumarin so affected the normal development of the wheat
as to cause stunting of leaf growth, with abnormal appearance
associated with a slightly altered absorption of plant nutrients,
both as to amount and ratio, the phosphate absorption being the
more normal. The fertilizer combinations high in phosphate were
the most effective in antagonizing the harmful effect of cumarin.
The dihydroxystearic acid also affected normal development,
causing a decrease in top growth, but no abnormal appearance, the
greatest abnormality being in this case observed in the root system,
which was darkened and much stunted and showed swollen root
tips, often bending into fishhooks, associated with a much altered
absorption of nutrient elements both as to amount and ratio, the
Phosphate and potassium absorption being greatly depressed, the
nitrate removal or disappearance being about as under normal
conditions, but relatively much greater. The fertilizer combina-
tions high in nitrate were the most effective in overcoming the
harmful effect of this soil constituent.
___ In view of this widely different behavior of these two toxic sub-
stances, entailing the interesting observation that they responded
differently to the different fertilizer combinations, it was thought
desirable to consider some results with other toxic substances.
In the first place, it was interesting to see whether the result
observed with dihydroxystearic acid, namely response to the nitrate,
was shown by another toxic body, and thus throw a little more
light on this phase of the question. For this comparison the
aldehyde vanillin was selected. This was known to be toxic from
ormer experiments, was known to be oxidized by the plant roots,
and was further known to be more readily oxidized when nitrates
4c BOTANICAL GAZETTE [JULY
were present,’ and so should be a body which would behave much
like dihydroxystearic acid.
In the present experiment with vanillin here recorded, the same
number of cultures (66), containing all the fertilizer combinations
possible in ro per cent stages, was used as in the experiment with
the dihydroxystearic acid and cumarin. The concentration of
vanillin used was 50 ppm. The duration of the experiment was
from March 7 to March 19. The solutions were changed every
three days as in the cumarin experiment already described, but no
analyses of the solutions were made in this case. The green weight,
however, was recorded.
The effect of the vanillin was not so marked on the tops as on
the roots, although in the regions of better growth this also was not
very prominent. The general appearance of the plants resembles
the effect produced by dihydroxystearic acid much more than the
effect produced by cumarin under the same circumstances. The
region of greatest growth appeared also, as in the case of dihy-
droxystearic acid, to be shifted toward the nitrogen end of the
triangle. The plant growth was 84 per cent of the normal as an
average of all the cultures.
For the present purpose, however, the growth in the cultures
respectively high in phosphate, nitrate, or potash is of paramount
interest. This grouping of the results obtained on the green
weights at the termination of the experiment is shown in fig. 3-
The relative growth in the cultures having so per cent and more of
phosphate was 85 per cent of the growth without the vanillin; for
the cultures mainly nitrogenous it was 88; and for the cultures
mainly potassic it was 82. It will be observed that the vanillin
depressed the growth least in the cultures high in nitrate, a result
in harmony with previous observations on the toxicity of vanillin
and in harmony with the action of dihydroxystearic acid. Both
of these substances have reducing properties; that is, they are
themselves readily oxidized; both have an inhibiting effect on root
oxidation and on root growth generally; both are overcome by
the fertilizer combinations which increase root oxidation to the
greatest extent. It was consequently thought to be of interest to
5 SCHREINER and REED, Jour. Amer. Chem. Soc. 30:85. 1908.
1912] SCHREINER & SKINNER—FERTILIZER SALTS 4I
see what the effect of an organic compound having oxidizing prop-
erties would be on plants growing in these various fertilizer com-
binations. For this purpose quinone, shown to be toxic to wheat
seedlings in a former research, was chosen, inasmuch as it is an
oxidizing substance and therefore in strong contrast to the vanillin
with its decided reducing properties. This fundamental difference
P2005
an : NH3
G. 3.—Showing the relative growth of normal and vanillin cultures in solutions
high j In i pics nitrate, or potash, respectively.
in the properties of the two compounds, it was thought, should
Show itself in an altered metabolism of the plants under the influ-
ence of two such widely different poisons, and the scope of the
Present experiment as to different fertilizer combinations should
lend itself to showing such differences in metabolism or fertilizer
Tequirement, and thus throw some light upon the behavior of crops
in the field toward fertilizers under oxidizing conditions.
In the experiments with quinone the fertilizer combinations and
42 BOTANICAL GAZETTE [yoLy
general technique were the same as in the preceding experiments
with vanillin and cumarin, the concentration of quinone being 10
ppm. No analyses of the solutions were made in this experiment.
The duration of the experiment was from March 23 to April 4.
The effect of the quinone on the development of the wheat was
in itself as definite, though perhaps not as characteristic, as the
effect of cumarin. The effect of the latter substance was to pro-
duce short, broad, irregularly developed leaves and stunted tops;
the effect of the quinone was to produce long, thin leaves, producing
tall, slender plants, so that at first glance the quinone in the con-
centration here used appeared to have had little effect on the growth
of the plants. Closer inspection, however, shows the plants to be
slender and weaker, although the leaves may be fully as long as the ~
normal leaves. The effect of quinone on plant growth, however,
is definitely shown by the decreased green weight. The root growth
is also affected.
The most interesting feature of difference between the normal
and quinone sets of cultures, observable when both sets are arranged
in triangular form according to the composition of the culture
solution, is the apparent or real shifting of the greater growth
toward the potassium end of the triangle in the quinone set, accom-
panied by a generally better relative growth in the potash angle.
This observation would seem to show that the quinone effect was
counterbalanced by the fertilizer combinations high in potash,
whereas cumarin was undoubtedly affected by the phosphate
fertilizers, as shown, and vanillin as well as dihydroxystearic acid
by the mainly nitrogenous fertilizers. This effect was not antici-
pated, but might easily have been, inasmuch as quinone is a strong
oxidizing substance and potash salts are known from a previous
research’ to be retarders of root oxidation, analogous to the opposite
effect of vanillin, a reducing substance overcome by nitrate known
to stimulate root oxidation.
The green weights obtained at the end of the experiment bear
out this observation. The relative growth in the quinone set was
75 cent of the normal. The chief interest, however, centers
R, O., and Reep, H. S., The réle of oxidation in soil Leak Bull.
56, Bureau ol f Soils, U.S. Dept. Agr. 1
1912] SCHREINER & SKINNER—FERTILIZER SALTS 43
in the comparative results obtained in the cultures containing 50
per cent and more of the phosphate, nitrate, and potash, respect-
ively, in order to see which of these was the most efficient in
antagonizing the action of quinone. The results of the grouping
of cultures on this basis, made as explained in the preceding experi-
ment, is shown in fig. 4. The mainly phosphatic fertilizer com-
binations show a relative green weight of 77 per cent of the normal,
P205
FELATIVE GROWTH =77.
= a ee
i NH3
hi F 1G. 4.—Showing the relative growth of normal and quinone cultures in solutions
igh in phosphate, nitrate, or potash, respectively.
the mainly nitrogenous 67, and the mainly potassic 83. It is
observed that the potash fertilizers were the most efficient in over-
coming the harmful effect of quinone.
This experiment with quinone was repeated, and this time the
solutions were analyzed as in the case of the cumarin experiment.
This second quinone experiment lasted from April 8 to April 20.
At showed the same general slender appearance of the plants, as
44 BOTANICAL GAZETTE [yoy
well as again showing the influence of the potassium fertilizers as
above described. In this experiment the green weight in the
quinone set as a whole was 79 per cent of that in the normal. The
results for the mainly phosphatic, mainly nitrogenous, and mainly
potassic fertilizers are 76, 77, and 85, respectively, again showing
the relative greater efficiency of the potash fertilizers in this
quinone experiment. |
These quinone experiments indicate clearly the harmful influence
of quinone on growth, and the effect of potassium in counteracting
this action of the quinone. In the second experiment the cultures
were analyzed for phosphate, nitrate, and potassium, and it is,
therefore, interesting to inspect these data, as was done with the
cumarin results. Only the 36 cultures having the combinations
of all three fertilizer salts are considered.
The amount of total P,O,+NH;+K,0 removed from solution
by the growing plants in the total number of 36 cultures was 1568
milligrams in the normal set and 1327 milligrams in the quinone
set, showing a decrease in the sum total of P,O,, NH;, and K.O
removed when quinone is present. In table III are given the
results for the P,O;, NH;, and K,O separately under the normal
conditions and in the quinone set.
TABLE Il
.
TOTAL MILLIGRAMS OF P20;, NH;, AND K,0 REMOVED FROM THE 36 CULTURE SOLUTIONS
CONTAINING ALL THREE OF THESE INGREDIENTS
| TOTAL ABSORPTION IN MILLIGRAMS] PERCENTAGE OF
RELATIVE QUINONE CULTURES
Normal Quinone asec 8 6!
Lf a Fog es 300.4 173.6 58 8
Ly fs RS ee Pee te eee 571.5 506.8 89 II
EO. 696.5 646.5 93 36
An inspection of these figures indicates strongly that the potas-
sium absorption in the presence of quinone has been more normal
than the other two nutrient elements. This is shown both by the
relative absorption in the third column and by the number of
quinone cultures showing normal or greater absorption of P.O;,
NH,, and K,O, respectively, in the last column.
1912] SCHREINER & SKINNER—FERTILIZER SALTS 45
We have, therefore, the interesting case ofa toxic oxidizing
body being overcome by a fertilizer salt having a restraining action
on the normal oxidative power of the root, accompanied by a
relatively greater absorption of this fertilizer element than under
normal conditions.
Discussion and summary
In the foregoing experiments with cumarin, vanillin, and quinone,
the effects of these toxic substances on the development of wheat
seedlings was demonstrable by three criteria:
1. By decreased green weight.
2. By the morphological effects as shown by their general appear-
ance. Cumarin-affected plants have characteristic stunted tops,
broad, distorted leaves; vanillin-affected plants are less character-
istic, but show decreased growth of top and strongly inhibited root
| growth; quinone-affected plants are tall and slender, with thin,
narrow leaves, in strong contrast to the cumarin-affected plants.
The substances show, therefore, a markedly different behavior in
detail, although all show a toxic effect in inhibiting growth.
3. By decreased absorption of plant nutrients. The cumarin
depressed potash and nitrate removal from nutrient solution more
than phosphate; the quinone, on the other hand, depressed phos-
phate and nitrate more than potash; the effect of vanillin was not
determined in this regard. It might be interesting to mention,
however, that dihydroxystearic acid, which appears to act much as
vanillin did, depressed phosphate, and potash more than nitrate.
In this respect again the influence of the various harmful substances
was different.
The various fertilizer salts acted differently in overcoming the
Tespective harmful effects of these toxic compounds. The mainly
phosphatic fertilizers were the most efficient in overcoming the
cumarin effects; the mainly nitrogenous fertilizers in overcoming
the vanillin effects; the mainly potassic in overcoming the quinone
effects.
This different action of fertilizer salts on the toxic com-
pounds is also illustrated by the diagrammatic representations in
fig. 5 of the regions of greatest growth obtained in the various
46 BOTANICAL GAZETTE [JULY
experiments. The triangle represents the various cultures con-
taining the fertilizer combinations, as is fully explained in fig. 1
and the accompanying text.
Under normal conditions, that is, without any toxic body present,
the greatest growth is found in those cultures low in phosphate and
about halfway between the nitrate and potash angles. This
P2 Os
K20 NH3
Fic. 5.—Diagrammatic representation of the region of greatest growth in the
triangle culture experiments with cumarin, vanillin, and quinone.
region of greatest growth is diagrammatically represented by the
circle marked normal in fig. 5. When cumarin is present in the
cultures, the effect was to cause the region of greatest growth to
shift in the direction of the phosphate angle, a condition which
may be diagrammatically shown by the circle marked cumarin.
With quinone, this region of growth was shifted toward the potash
angle, and with vanillin toward the nitrate angle, as illustrated in
the diagram.
1912] SCHREINER & SKINNER—FERTILIZER SALTS 47
This shifting of the region of greatest growth was accompanied
by a corresponding change in the absorption of plant nutrients,
although this is not as marked as the green weight. All of these
facts are in harmony with the conclusion drawn from the data
already given, that phosphate fertilizers were antagonistic to
cumarin, that potash fertilizers were antagonistic to quinone, and
that nitrate fertilizers were antagonistic to vanillin and to dihy-
droxystearic acid.
In regard to the exact mechanism of the chemical or physio-
logical character of the interactions between these toxic substances
and the fertilizer salts, nothing definite can be said. Attention,
however, should be called in this connection to the fact that the
teducing poisons vanillin and dihydroxystearic acid are antago-
nized by those fertilizer combinations which stimulate oxidation,
and that the oxidizing poison quinone is antagonized by the fer-
tilizer combinations checking oxidation, thus indicating that there
is some correlation between these functions. A discussion of the
interaction of cumarin and phosphate fertilizers would be mere
speculation in the present state of our knowledge.
Attention must also be called again to the fact that the obser-
vations here recorded for phosphate, nitrate, and potash were
obtained with the salts, calcium acid phosphate, sodium nitrate,
and potassium sulphate, and that the observed results, therefore,
may be caused by these substances as a whole, that is, as com-
binations rather than individual elements. For deciding this
question, further investigation is necessary, involving experiments
with other salts and combinations.
These actions of the different fertilizer combinations or differ-
ent fertilizer requirements, as they may be styled, show a certain
parallelism with field observations on soils and their fertilizer
requirements, and one is tempted to ask to what extent may the
different fertilizer requirements of different soils or of the same soil
under different conditions be influenced by the same cause. That
harmful bodies occur in soils has been amply shown, and that these
are influenced directly or indirectly by fertilizer salts is also clear
from this and other researches. That the constitution of the
organic matter varies from soil to soil, and in the same soil under
48 BOTANICAL GAZETTE [JULY
different conditions of aeration, drainage, and cropping, is likewise
clear. The presence of compounds inimical to plant growth by
virtue of a property resembling that of any of the above-mentioned
poisons might therefore cause a different fertilizer requirement, a
requirement which might even change from time to time according
to the nature of the biochemical reactions producing the body, or
according to the nature of the plant remains in the soil; in other
words, according to rotation, with its necessary altered soil manage-
ment, and the altered biochemical changes produced in the different
plant remains.
The action of fertilizers on soils is a much contested question,
but the weight of evidence is against the assumption that their
effect is due altogether to the added plant food. If so simple an
explanation were the true one, nearly a century of investigation
of this problem by scientists of all civilized nations would surely
have produced greater. unanimity of opinion than now exists 1n
regard to fertilization. Thoughtful investigators everywhere
are finding that fertilizer salts are influencing many factors which
contribute toward plant production besides the direct nutrient
factor for the plant. It is this additional influence of fertilizers
which makes them doubly effective when rightly used and ineffi-
cient when improperly used. To this influence of fertilizers on soil
and biological conditions is due their capriciousness when applied
on the theory of lacking plant food, and any study which throws
further light upon the mooted question is of direct help toward
reaching that view of soil fertility and soil fertilization which will
eventually result in a more definite system of fertilizer practice,
to the end that surer and safer returns are obtained from their use.
This will tend to extend fertilizer practice by making it more
remunerative and rational than in the past.
Bureau or Sorts
U.S. DEPARTMENT OF AGRICULTURE
WASHINGTON, D.C.
THE EFFECT OF EXTERNAL CONDITIONS UPON THE
AFTER-RIPENING OF THE SEEDS OF
CRATAEGUS MOLLIS
CONTRIBUTIONS FROM THE HULL BOTANICAL LABORATORY 157-
WILMER E. Davis AND R. CaTLIN ROSE
It is well known that the seeds of many plants do not germinate
immediately after ripening, but only after a period of rest which in
some cases no doubt extends into years. Nose and HANLEIN (16),
for example, kept certain weed seeds under germinating conditions
for a period of 1173 days without germination.
While various workers have done much in the way of adding to
the list of seeds that require a rest period before germination, little
has been done to determine the real cause of this delay or dormancy
on the part of the seed. During this period, it is assumed that the
seed undergoes certain changes, at the completion of which germina-
tion may take place. This period of preparation for germination
has been termed the after-ripening period. The term after-ripening
then may be made to include the necessary protoplasmic changes
antecedent to germination; changes involving the release of di-
gestive and respiratory enzymes, thus leading to rapid metabolism;
or disintegration or other modifications of incasing structures that
limit the water or oxygen supply or even mechanically hinder
Stowth. But in relatively few cases do we know to which of these
dormancy is due. In most literature the cause is assumed to be
the need of protoplasmic changes in the embryo. In this paper
we have used the term after-ripening in reference to embryonic
changes whether protoplasmic or metabolic, in contrast to those
changes that merely affect the incasing structures. By germination
we mean the growth of the hypocotyl.
Many more or less successful attempts have been made to
shorten or eliminate altogether this period of inactivity on the part
of the embryo by certain stimuli designed to arouse the dormant
Protoplasm to activity. Lately FIscHER (5) observed that seeds of
certain water plants might be-kept in water free from fermentation -
ng : [Botanical Gazette, vol. 54
5° BOTANICAL GAZETTE ; [JULY
for years without germination, but if fermentation were set up,
the seeds would soon after begin to germinate. He attributed
this to the effect of H+ or OH— ions acting as stimuli on the
dormant protoplasm. MU.ter (15) found that the seeds of
Eichhornia and Heteranthera germinate only after desiccation.
Crocker (1), working on the seeds of various water plants, includ-
ing Eichhornia and others reported by F1scHer, has shown that
the protoplasm is not dormant. He found that the seeds of Eich-
hornia, Alisma Plantago, and Sagittaria germinate readily in dis-
tilled water if the coats were broken, and concluded that bases and
acids here must have their effect upon the seed coats rather than
upon the embryos. He also concluded that the effect of the coats
in many of the seeds of water plants is mainly to limit the water
rather than oxygen supply, since little if any oxygen is needed by
them for germination.
KINzEL (11) and HEINRICHER (8) have shown that in many
seeds light is necessary for germination. Seeds kept under ordinary
germinating conditions for months in darkness failed to germinate,
but when placed in light germinate within a few days. Both
KinzEL and HEINRICHER seem to have taken it for granted that
the changes induced by the light have to do with the embryo.
But even here it is barely possible that light in some way affected
the seed coat, rendering it permeable.
It has long been known that cold has an influence in some way
on the germination of various seeds. Many seeds are thought to
germinate only after being subjected to freezing and thawing:
But as to the exact effect of the cold in bringing about germination
there is as yet nothing very definite.
PamMEL and Lumuis (17) found that many weed seeds that
failed to germinate under ordinary germinating conditions germ
nated more or less readily after freezing. PammeEL and KING (18)
have shown that freezing and thawing not only increase the per
centage of germination in many weed seeds, but that the seeds
thus treated in many cases germinate more quickly than those
kept dry before planting. Fawcett (4) likewise has shown that
freezing and thawing:shortens the dormant period of many weed
seeds, and that the percentage of germination of seeds exposed to
1912] DAVIS & ROSE—AFTER-RIPENING 51
the weather is in many cases considerably higher than of those
kept dry. In wild rye, for instance, the dormant period was
reduced from 9 to 5 days, and the percentage of germination was
raised from 2 to 48. But the limiting factors to growth have not
been located in any of these cases.
Investigation
This work on the germination of the seeds of the hawthorn
(Crataegus mollis) was undertaken in order to determine so far as
possible the influence of the various external conditions affecting
their after-ripening. Hawthorn seeds usually do not germinate
until the second or even third year after the fruit has ripened.
Kuntze (14) wrote in 1881: ‘Hawthorn berries (Crataegus)
which do not germinate until the second year are peculiarly treated.
They are mixed with sand, thrown into a heap, and watered a few
times in a cold house during the winter, and sown the following
spring. They are turned over several times so that the pulp may
decompose.” The Cyclopedia of American horticulture (3) also
refers to this delay in the germination of the seeds of the hawthorn
and gives the method employed in their germination essentially
as that given by Kuntze.
In considering the after-ripening and germination of the haw-
thorn, the various structures about the seed, as the pericarp and
carpels, as well as the testa and embryo itself, must not be over-
looked. The pericarp is separated from the carpels by decay or
by being eaten off by some animal. It often shrivels and remains
intact for a considerable length of time. The carpels are bony and
the seed is freed only after much weathering, when the carpels
become more or less porous to water and are split by the swelling
of the seeds. Both of these structures in nature, by the prevention
of a sufficient supply of water and oxygen, may tend to prolong
after-ripening as well as delay germination.
Our first work was to determine the behavior of the seeds under
ordinary germinating conditions. To do this we removed the pulp
and the bony carpel. The seeds were than placed upon wet cotton
in Petri dishes, both in the laboratory and the greenhouse. They
Temained in this condition for months without any sign of germina-
*
52 BOTANICAL GAZETTE [JULY
tion, and all those seeds that had suffered injury, however slight,
in removing them from the carpels invariably decayed.
To remove the possibility of coat effects, we next removed the
testas and treated the embryos as above; when thus treated an
occasional hypocotyl grew, varying from none to 3 or 4 per cent.
CROCKER (2), who previously employed this method, indicated a
higher percentage of growth. The behavior of the embryos under
these conditions as pointed out by him is interesting in that it
shows a remarkable correlation between the cotyledons and the
hypocotyl. In the light the cotyledons soon turn a dark green and
enlarge often to several times their original size. The hypocotyl
does not elongate, but remains short and blunt. In case of ger-
mination after complete after-ripening, the hypocotyl takes prece-
dence and elongates rapidly, while the cotyledons increase in size
much more slowly and never reach the size attained in case the
hypocotyl fails to elongate. In darkness the behavior was similar,
except that the cotyledons contained xanthophyll.
We next carried on experiments to determine the effect of low
temperatures in bringing about after-ripening and germination.
The first set of experiments was carried on in an ordinary ice chest
so arranged as to admit light to some of the cultures. With this
we were able to obtain a temperature of 5°-6° C.
In all cases the seeds treated were placed on wet cotton in Petri
dishes or in air-tight jars, excepting those seeds that were subjected
to low temperatures in a dry state or under water. These were
treated in test tubes with cotton plugs. Table I gives the results
of the first set of experiments.
In these cultures the number of seeds germinated compared with
the total number treated may seem rather low, varying as they
do from 50 to 80 per cent. This is not due to the seeds failing
to germinate when removed from the cold, but almost entirely
to loss during the process of after-ripening. It is quite difficult to
remove the seeds from the carpels without injuring them. While
in all cases they were removed by carefully splitting the carpels
with the point of a strong knife, yet many suffered more or less -
injury that escaped observation until placed upon the ice. The
seeds with their testas broken invariably decayed during the pro _
1912] DAVIS & ROSE—AFTER-RIPENING 53
cess. Seeds with the testas broken decay more readily than those
with the testas removed, because the edges of the broken testas
offer a good lodging-place for bacteria and the spores of various
fungi. The seeds during the after-ripening process require con-
siderable care. They should be removed occasionally, washed,
sorted, and placed upon clean wet cotton. They are especially
liable to decay if they are left ina mass. The loss in after-ripening
can be greatly reduced by thoroughly washing the seeds before
placing them in the cold.
TABLE I
N Ge Sin
oO. number
No. | N iti : 2 e
édeure seeds apes berg — Meath her daleed In light | In dark within meee
pe todays| after
20 days
ty 400.1 Carneleos oo; 5-6° | 96 _ 221 264
13 woo; Carmel O03 fon fe 5-6° | 242 — ° °
18 noo | Catpels of. oo cc:. 5-6° a1 fee 250
17 400.1 Cameleon. 2040022500, 5s-6° | 242 —- ° °
9 400 | Carpels = bug Seva. es 5-6° 6 — 5 219
B....| 400 | Cite er 77 ee 5 96 “4 age git
16....| 400 | Carpels of (seeds dry)..| 5-6° | 096 _ ° °
19....} 400 | Carpels off (seeds under
ch awetee ck es 5-6° | 150 —_ ° °
Germination at 10°—12° C.
When the seeds had been left a sufficient time in the cold to
after-ripen, the percentage of germination based upon the number
coming from the cold was always ne running from go to 98 per
cent.
When the above seeds were removed from the cold and were
placed in a water bath at a temperature of 10° to 12° C. to germinate,
practically all the seeds, except those treated dry or under water
or with carpels on, germinated, but the time required was some-
what extended. In later experiments, where seeds were removed
from the cold to the temperature of the greenhouse, the period of
germination covered a much shorter time, as will be seen in table IT.
The seeds treated under water and those treated dry showed no
signs of after-ripening; when they were removed from the cold,
they decayed. The failure to after-ripen under water was probably
due to an insufficient supply of oxygen. Seeds treated with carpels
54 BOTANICAL GAZETTE [JULY
on showed considerable progress. in after-ripening. During the
latter part of the period in the cold there was occasional germina-
tion, and when the carpels and coats were removed, the embryos
generally responded normally.
TABLE II
Germina- | Germina-
No. culture} No. seeds | Temperature Roce Bes otttin Remarks
ys
Bes on 150 5-6 a2 109 112
Avent 150 73 45 68
re aes 150 go 82 83
AGG E50 2 (0) 33 75 ° °
15, ea 150 2tO 3% 77 ° °
25 Cs 150 210 -=3 114 ° °
1355; 150 5-6 130 ° ° Treated without oxygen
FO eas 150 5-6 130 fe} ro) ith 2 per
n
i... 150 5-6 go 5 5 Treated without oxygen —
Bonk 150 ° ° ° Treated without oxygen
ere 150 ° go fe) Trea i pe
cent oxygen
The above experiments were conducted in an ice chest so con-
structed that by means of salt three fairly constant temperatures
were obtained: 5° to 6°, o°, and —2° to —3° C. The seeds were
freed from the carpels and after-ripened in the dark.
It will be noticed that the time the seeds were left in the cold
to after-ripen is in some cases less than that in the previous table,
and also that the seeds germinated more quickly when removed
from the cold. The seeds were removed from the cold directly to
the greenhouse instead of the bath, as in the first set of experiments.
In culture no. 1, 10g seeds responded within 3 days, and the
3 remaining within 5 days. Not more than 2 or 3 seeds decayed
after they were removed from the cold. The average length of the
hypocotyls after 5 days was 15 mm. In no. 2, the germination
was slower, the hypocotyls elongated less rapidly, and many
decayed when taken from the cold. No. 21 remained 17 days
longer in the cold than no. 2, which no doubt accounts for the
greater number germinated. Nos. 4, 23, and 24, although left at
the low temperature from 75 to 114 days, showed no signs of
germination.
1912] DAVIS & ROSE—AFTER-RIPENING 55
Nos. 10, 20, 5, 3, and 7 were arranged to determine the relation
of oxygen to after-ripening. The seeds in these cultures were
placed on wet cotton in Novy jars of about a liter capacity. Nos.
10, 5, and 3 were without oxygen. The oxygen in no. 5 was removed
by pyrogallate. In nos. 10 and 3 the jars contained hydrogen
washed in pyrogallate. No. 20 contained hydrogen washed in
KOH and KMn0O4. The hydrogen used was from the Linde Air
Products Company of Buffalo, N.Y. Upon analysis it was found
to contain 2 per cent oxygen. The results with no oxygen or even
2 per cent were mainly negative.
Several cultures were treated with ether in addition to the cold.
The seeds were placed in air-tight jars of a liter capacity. In each
jar there was a small bottle containing 10 cc. of water, to which
had been added ether varying in the different cultures from 0.25 cc.
to rcc. The jars were then placed in the cold from 8 to 16 days.
At the end of this period the seeds were removed from the jars,
placed in Petri dishes, and returned to the cold. The germination
in every case was less than that of the control culture without
ether. While ether may have a stimulating effect upon germinat-
ing seeds, the concentrations used here retarded rather than
hastened after-ripening.
To determine the effect of a temperature upon after-ripening
somewhat higher than the ones previously employed, the following
cultures were placed in a water bath December 1 in which the
temperature at the beginning was g’-10° C. Tap water was used
in the bath and the temperature varied with the season, ranging
from the above temperature to as high as 22° C. in July and August.
The seeds were freed from the carpels. Table III shows the results
of these experiments. As fast as the seeds were after-ripened and
germinated, they were counted and removed from the bath.
All these cultures were put in the water bath December 1,
excepting no. —1, which was placed there 10 days later. This gave
it 10 days less exposure to the low temperature at the beginning,
and this in part, at least, may account for the difference in the
number of seeds germinated between it and no. 1. There is also
brought out in this table a very marked falling off in germination
as the temperature rose, which means, of course, a similar falling
56 BOTANICAL GAZETTE [JULY
off in the number of seeds after-ripened. Several of the seeds that
germinated late in the season had rather stunted hypocotyls. The
difference in the number of seeds germinated in the light and the
dark at these temperatures seems to indicate that light at least at
these temperatures had some influence on the after-ripening.
TABLE III
CARPELS No. GERMINATION DURING a
Nos | NO a a ee. Days | §& i ae
SEEDS IN o e )
m | Off BATH | 9 Q | Mar.!| Apr.| May | June | July | Aug-| &
I..] 400 fi) gmat’ C,1 295. 1-/ 46.)-o6-] 45 | 3h 1.28) Eee
—1..| 400 / | 9-22°C.| 264) / 8494 391-47) 184 35
2..| 400 / | 9-22°C. | 275 Oi £7 Sh 7) Se eee
S240 | 7 g-22 C. } 275 | / eo 2) Oo Ol oy er es
5.1 400-4 g-22° C. | 275 / Oot O16 64: 6140
To determine the effect of alternating high and low tempera-
tures, a culture (no. 9) was placed in the above water bath April
13. The temperature of the bath at this time was about 13° C.
It was left at this temperature for 10 days, when it was removed
to the ice chest at a temperature of about 6° C. This 10-day —
alternation was kept up until September, or for 140 days. None
of the seeds germinated during this time, although they had been
exposed one-half of that time, or 70 days, to a temperature most
suitable for after-ripening. The high temperatures appear to have
counteracted the effect of the low temperatures.
In order to ascertain the importance of the testas in after-
ripening, they were removed from 50 seeds and the embryos were
placed in the cold at a temperature of about 6° C. At the end of
28 days several of the embryos showed signs of germination. They
were then removed from the cold to the greenhouse, and within 10
days 39 of the 50, or 78 per cent of the seeds treated, had germinated.
The time required for after-ripening seeds without testas was about
one-third of that required for seeds with testas, under conditions
otherwise the same.
In the after-ripening of these embryos the correlation between
cotyledons and hypocotyl was made very evident. The embryos
to after-ripen must be kept,at a temperature sufficiently low to
inhibit growth in the cotyledons. When the embryos were exposed
Igt2] DAVIS & ROSE—AFTER-RIPENING 57
but a short time to high temperature, the cotyledons began to
enlarge, and if exposed to light to turn green and after-ripening
would not take place.
The importance of water as a factor in the after-ripening of the
seeds of the hawthorn needs to be emphasized. Those seeds kept
thoroughly wet during this process gave the best results, as indi-
cated by the germination when removed from the cold. The
prolonged period of after-ripening of seeds within the carpels, the
shorter period when the carpels were removed, and the still shorter
period when both carpels and testas were removed show that these
structures add greatly to the resting period. In order to determine
to what extent the carpels and testas interfered with the taking up
of water by the embryo, we took two lots of seeds, one with the
‘carpel intact, and the other with carpels removed. Each lot was
soaked in water at room temperature for 48 hours. The testas
were then removed from a portion of the second lot. These three
sets of seeds, one with carpels intact, one with testas, and the other
with both carpels and testas removed, were placed upon wet cotton
in Petri dishes and left in an ice chest at about 7° C. for 14 days.
At the end of this period the carpels and testas were removed from
all seeds which had been treated with them on, and the water con-
tent of the embryos determined for the three conditions. The
embryos were dried in vacuo over H,SO,. The determinations
were made in duplicate and are given in table IV.
TABLE IV
No. seeds Condition of Wet weight Dry weight | water content | Water content
emb duri of emb: f{ embryos . i
cat [name ismar | er | “iam | Meese
Ae. Carpels on..| 0.5114 0.3844 0.127 24.8
esi Bees Carpels on..| 0.3186 ©. 2396 0.0796 24.9
| MO eas Testason...| 0.4018 0.2730 0.1278 32.5
ay ee as Testas on...| 0.6056 0.4180 0.1876 39-9
a ee Testas off... 0.6866 0.4100 0.2766 39-4
KP a Testas off...| 0.4810 ©. 2904 ©. 1906 39.6
GASSNER (6) has shown that
seeds of two South American
tasses, Chloris ciliata and C. distichophylla, after-ripen in dry
Storage. The most favorable period of dry storage was found to
be 30-40 weeks. He also found light to be an important factor
58 BOTANICAL GAZETTE [JULY
in their germination when removed from dry storage, light favoring
and darkness hindering germination. After 10 weeks of dry stor-
age, there was no germination in darkness at the optimum tempera-
ture, but after 39 weeks, 7-8 per cent germinated under the same
conditions. In light after g weeks of dry storage, 73 per cent
germinated under the same conditions. In a recent article (7)
covering a study of Stenotaphrum glabrum and Paspalum dilatatum,
GaASSNER found that P. dilatatum after-ripened in 1 to 2 weeks in
dry storage at 50-60" C.
The after-ripening of these seeds in dry storage is most interest-
ing, especially if it is a true case of after-ripening, that is if the
cause of delay lies in the embryo rather than in the coat. If the
delay were due to an impermeable coat, it would not be difficult
to understand how drying might cause it to rupture or change’
otherwise its permeability to water or oxygen. The presence of»
water is usually necessary to initiate chemical changes. This is
especially true for germination, and in the hawthorn, at least, is
also true for after-ripening, since neither the seeds kept dry for
long periods at the temperature of the laboratory nor at tem-
peratures most favorable for after-ripening showed any signs of
germination when placed under germinating conditions.
The claim that certain seeds after-ripen in dry storage is quite |
general. KuinzeL (13) found that for oats kept in dry storage the
percentage of germination increased for 8 months after harvesting
and then gradually fell. But in all these cases there is need of a
thorough analytical study of the processes involved in the after-
ripening.
Some general considerations
The preceding tables indicate that the after-ripening in the
hawthorn takes place at low temperatures, the optimum for which
is 5° to 6°C. But the process goes on even at 0° C., while at —2° C.
to —3° C. it makes little or no progress. Freezing and thawing,
then, do not appear to be the ideal conditions for after-ripening.
The value of freezing and thawing to seeds which are lying in the
soil, in which cold is a factor in the after-ripening, very likely con-
sists in rupturing the seed coat or other external structures, by
means of which water or oxygen are permitted to enter. Especially
1912] DAVIS & ROSE—AFTER-RIPENING 59
is this true of seeds in which the cause of the delay is in the external
structures rather than in the embryo. In the hawthorn, freezing
and thawing undoubtedly bring about a splitting of the bony
carpels sooner than would otherwise occur, and in this manner
shorten the period of after-ripening.
Temperatures alternating between that most favorable for
aiter-ripening, as 5° to 6° C., and temperatures ranging from 13°
to 22° C. were not favorable to after-ripening. While we did not
employ other alternating temperatures than those above, we are
led to believe that there is always some favorable constant tem-
perature at which after-ripening will take place most readily, and
that any variation from this temperature either above or below
will retard it. ;
There is considerable variation in the time in which individual
seeds after-ripen, as is indicated in table III and again in those seeds
that were removed from the cold too soon. In the latter case there
was always a large number of seeds that failed to germinate. These
in nearly all cases would germinate if the testas were removed, but
when not so treated and left at high temperatures, they would lie
upon the moist cotton for weeks without germinating. The higher
temperatures seem to inhibit the process of after-ripening. The
Process of after-ripening then is interesting in that it does not obey
the van’r Horr temperature law for rate of chemical reactions, but
goes on faster at low temperatures. If this temperature law applies
to the individual metabolic processes involved in after-ripening,
it must apply to them with quite different coefficients, with the
general result that the process as a whole falls with a rise of
temperature.
While the results with low oxygen pressure were mainly negative
or nearly so in all cases, we are not prepared to say that after-
ripening cannot take place under low oxygen pressure or even in the
entire absence of oxygen if sufficient time is allowed, but oxygen
certainly favors after-ripening. We are now carrying on experi-
ments to determine more definitely the various points in reference
to after-ripening and oxygen pressure.
Light does not seem to enter into the after-ripening of the
hawthorn to any great extent. At the optimum temperature after-
60 BOTANICAL GAZETTE [JULY
ripening goes on equally well in dark or light. At a temperature
considerably above the optimum, but not sufficiently high to stop
the process altogether, light does appear to have some influence, as
is indicated in table III.
The seeds of the hawthorn will germinate at a temperature
slightly above o° C. We have found them in nature germinating
in early spring, when the ground was yet quite cold and wet.
Seeds placed on ice for after-ripening germinate in this condition
after going through that process. The germination, however, takes
place irregularly, and often requires a considerable period before all
the seeds of the culture are germinated. But if the seeds are
removed from the cold when they show signs of germinating, and
placed at the temperature of the greenhouse, the germination takes
place very rapidly, often reaching 90 per cent or more within two
or three days. The sudden change of temperature when the after-
ripening is complete acts as a powerful stimulus to germination,
but if after-ripening is not complete, it seems to inhibit the latter.
How widespread this condition of seeds is, which requires after-
ripening, that is, some change involving the embryo itself before
germination becomes possible, is not known. All seeds that are
slow to germinate, from whatever cause, have too frequently been
put into this class. In most cases the delay is evidently not to be
found in the embryo at all, but in the seed coat or some other
external structure which prevents or limits the taking up of water
or oxygen or mechanically inhibits growth. The only way to
determine whether the delay is due to after-ripening or to hindrance
of incasing structures is to remove the external parts and subject
the embryo to germinating conditions.
Dr. Eckerson of this laboratory is making a study of the
internal changes that take place in the seeds of the hawthorn during
the process of after-ripening. The work is now well under way-
Conclusions
The seeds of the hawthorn do not germinate immediately after
. the fruit has ripened, but have a latent period of one or more years.
The cause of the delay is very largely in the hypocotyl rather
than in the cotyledons or any of the external structures.
1912] DAVIS & ROSE—AFTER-RIPENING 61
If the seeds are removed from the carpels and kept very moist
and at a temperature of 5° or 6° C., the latent period may be
shortened to 2.5—3 months, and if the testas are removed and the
embryos treated, the period may be reduced to 30 days. Tem-
peratures below o° C. are not favorable for after-ripening. Seeds
kept at —2° to —3° C. did not after-ripen. Seeds at o° C. after-
ripened, but not so readily as those kept at a few degrees above
o C. The most favorable temperature for after-ripening seems to
és 5-6 C,
Low temperatures alternating with high tariperatures: are not
favorable for after-ripening.
If the seeds are removed from the cold chamber before they
| have passed through the after-ripening period and subjected to the
_ temperature of the greenhouse, the high temperature either stops
\or greatly retards the process of after-ripening.
If the seeds are completely after-ripened and removed from the
cold to the temperature of the greenhouse, they germinate very
quickly. The high temperature greatly stimulates the process of
. germination.
After-ripening readily takes place under ordinary oxygen pres-
sure, but it has not been fully determined to what extent the oxygen
pressure may be reduced and the process still go on.
/ The pulp, carpels, and seed coat itself tend to delay the process
of after-ripening, probably by preventing the free access of water.
\The changes that take place in the embryo during the after-ripening
are not yet known. |
Seeds treated dry as well as those treated under water did not
after-ripen.
While after-ripening and germination in the hawthorn is a’
continuous process, that is, we cannot tell where one leaves off and
the other begins, the optimum temperature for the latter is con-
siderably above the optimum for the former.
In conclusion, we wish to express our thanks to Dr. WILLIAM
CRocKER, at whose suggestion this work was undertaken and who
offered many valuable suggestions during its progress.
Tue UNIversity oF CHICAGO
62 BOTANICAL GAZETTE [JULY
LITERATURE CITED
1. CROCKER, WILLIAM, Role of seed coats in delayed germination. Bot.
GAZ. 42:265~291. 1906.
, Longevity of seeds. Bor. Gaz. 4'7:69-72. 1909.
3. Cydapedia of Amer. horticulture, pp. 394-397.
4. Fawcett, H. S., Viability of weed seeds under different conditions of
treatment and study of their dormant periods. Proc. Iowa Acad. Sci.
1908
5. FIscHER, ALFRED, Wasserstoff- und Hydroxylionen als Keimungsreize.
Ber. Deutsch. Bot. Gesells. 15: 108-122. 1907.
6. GASSNER, Gustav, Ueber <i ininbedingithecn einiger siidamerikanischer
Gramineen-Samen. Ber. Deutsch. Bot. Gesells. 28: 350-364. 1910
2 : eber Keimungsbedingungen _ einiger stidamerikanischer
Gramineen-Samen. Ber. Deutsch. Bot. Gesells. 28: 504-512. 1910
8. Hetnricuer, E., Beeinflussung der Samenkeimung durch das Licht.
Wiesner Festechrift. Wien. 1
ie Samenkeimung und dus Licht. Ber. Deutsch. Bot. Gesells.
ree soe tor. 1908.
Io. , Keimung von Phacelia tanacetifolia Benth. und das Licht. Bot.
Zeit. 67: 45-66. 1909.
11. Kinzer, W., Die Wirkung des Lichtes auf die Keimung. Ber. Deutsch.
Bot. Conclls: 26a: 105-115. 1908.
, Lichtkeimung; Sper gs und Erginzungen. Ber. Deutsch.
Bot. Gesells. 27:2 530-545. I
, Ueber die ice halbreifer und reifer Samen der Gattung
2.
12.
3- Igo00.
14. Kuntze, Ricuarp E., Germination and vitality of seeds. Mem. Torr.
Bot. Club. rgor.
15. MULLER K., See PFEFFER’s Physiology of plants. English ed. 1: 210. 1903:
16. NosBE, F. ee HANteIN, H., Ueber die Resistenz von Samen gegen die
adusseren Varcenn der Nelaning Landw. Versuchs.-Stat. 20: 71-96. 1877-
17. Pammet, L. H., and Lumais, G. M., The germination of weed seeds.
Ames, Ia. 1903. :
18. Pammet, L. H., and Kinc, CHar.orte M., Results of seed investigations
for 1908 and 1909. Bull. 115. Ames, Ia. 1010.
THE STRUCTURE OF THE STOMATA OF CERTAIN
CRETACEOUS CONIFERS’
W. P. THOMPSON
(WITH PLATES V AND VI)
The structure of the stoma is remarkably uniform in all members
of the plant kingdom, from Anthoceros to the highest angiosperms.
It consists essentially of an aperture surrounded by two guard
cells which may be more or less sunken and protected by adjacent
cells. The only deviation from this organization has been described
for the fossil genus Frenelopsis, first by ZEILLER,? and more recently
by Berry.’ These authors state that in place of the usual two
guard cells, each stoma of Frenelopsis is surrounded by four or
five guard cells in the form of a rosette. The uniqueness of this
Supposed condition made it desirable that the subject should be
reinvestigated, and for this purpose I have had access to material
of Frenelopsis occidentalis (Heer), supplied by Professor ZEILLER
from a collection made at Nazareth, Portugal, by Professor
CHorrart.
The characters of the genus Frenelopsis have been given in
detail by ETTINGSHAUSEN,’ SCHENK,' and others. It is a cretaceous
conifer of disputed affinities, being referred by some authors
to the Cupressineae and by others to the Gnetales. The leaves
are decussately arranged in twos or fours at the nodes of thé jointed
Stem. They are reduced, squamiform, and appressed. The inter-
nodes functioned as leaves.
The epidermal characters of Frenelopsis occidentalis have been
* Contributions from the Phanerogamic Laboratory of Harvard University»
a R., Observations sur quelques cuticules fossiles. Ann. Sci. Nat. Bot.
+13. 1882,
> Berry, E. W., The epidermal characters of Frenelopsis ramosissima. Bot.
Gaz, 59: 305-309. figs 2. 1910.
‘ Errincswausen, C., Abhand. k.k. geol. Reichsanstalt. Vol. I.
‘ ScHENK, H., Palaeontogr. 19:13. —.
mane [Botanical Gazette, vol. 54
64 BOTANICAL GAZETTE [JULY
described by ZeEtLtER.6 The cells are rather small, roughly
rectangular, and very thick-walled. The very numerous stomata
are arranged in irregular lines which give a striated appearance
to the unmagnified specimen.
A single stoma is shown in surface view in fig. 1. The central
aperture is surrounded by the five ‘‘guard” cells of Berry and
ZEILLER. A conical projection can be distinguished extending
from each cell to the common center and together forming the
rosette. These projections are really below the surface, and, since
they are in focus, the opening at the surface is indistinctly seen
above them as a pentagonal area whose walls coincide with the
bases of the cones.
A clearer idea of the relation of the parts may be obtained
from fig. 2, which is a photograph of a vertical section through one
of the stomata. The conical processes of the so-called ‘‘guard”’
cells are here seen to project into the middle of a cavity. At the
upper limit of this cavity, that is, at the surface, the epidermal cells
again approach each other to form, not conical projections, but the
pentagonal opening seen indistinctly in the photograph of the
surface. These complicated cells are regarded by both Berry and
ZEILLER as guard cells, obviously unlike the guard cells found any-
where else in the plant kingdom. ZEILLER compares them with
those of Marchantia as follows:
Le seul fait qui me semble avoir quelque analogie avec cette constitution .
particuliére des stomates, serait celui qu’on observe chez les Marchantiées, ou
les pores stomatiques sont bordés par cinq ou six cellules, mais qui laissent
entre elles une ouverture en forme de canal, et non pas une fente en étoile»
comme dans l’espéce dont je viens de parler. II serait cependant assez singuliet
et assez peu vraisemblable que cette forme étoilée des stomates fat un fait
isolé, n’existant que chez le seul Frenelopsis Hoheneggeri, et peut-étre faut-il
s’attendre a la retrouver quelque jour sur d’autres plantes fossiles, sinon méme
dans la nature vivante.
In his conception of their arrangement, BERRY disregards that
part of the cell above the diverticulum, although he figures it in his
low-power drawing.’ Aside from their unique number and dispos!-
6 ZEILLER, R., Elements de palaeobotanique. Paris. 1900.
7 Loc. cit., p. 307.
1912] THOMPSON—STOMATA OF CRETACEOUS CONIFERS 65
tion, it is difficult to imagine how these structures could effectually
serve as guard cells.
The proper conception of the arrangement and homologies of
these parts may be most easily obtained from an examination of
living forms. The conditions existing in Agathis bornensis are
represented in fig. 6, which is a photograph of a vertical section of
the base of the leaf of that species. The two conspicuous oval
cells almost in contact are the sunken guard cells. Inclined above
- them, with their small extremities at the strongly cutinized surface,
are the accessory cells. Each of the latter is seen to have a slight
projection into the cavity some distance above the guard cells.
Viewed from the surface (fig. 7), the accessory cells are seen to be
four in number surrounding the opening. From the same view-
point, the guard cells (fig. 8) are seen to be fwo in number, and
arranged in the usual manner.
These conditions at once suggest that the so-called guard cells
of Frenelopsis are really accessory cells, and that we must look
below them for the true guard cells. As stated by both Berry and
ZEILLER, structural material of the epidermis only is available, so
that the depressed guard cells are not likely to have been preserved.
Nevertheless, diligent search reveals their presence in many favor-
able specimens. Fig. 3, which is a photograph of another stoma
in section, shows two well-preserved guard cells at the bottom of
the Cavity into which the conical structures project. Fig. 4 shows
another stoma with unmistakable guard cells below the accessory
cells. In this figure the end of a projection from another acces-
sory cell has been cut off and appears in the center of the stomatic
cavity. In the majority of the stomata examined in section, no
Suard cells can be distinguished; in others, fragments have been
Preserved, especially the outermost wall, which appears to have
been more strongly lignified; in still others, the whole structure is
Preserved in exactly the relations which one would expect in living
material,
It is still more difficult to observe the guard cells in surface
. View, Owing to the fact that they are covered by the extremely thick
accessory cells. This circumstance also entirely precludes their
reproduction by photograph. Nevertheless, examination of the
66 BOTANICAL GAZETTE [JULY
epidermis from beneath reveals their presence in a condition of
good preservation in some instances, and of imperfect preservation
in many others. A camera lucida drawing showing their typical
arrangement above the accessory cells (below in nature) is presented
in fig. 5. They are seen to have the normal form. The thinness
of their walls probably accounts for the imperfect state of preserva-
tion.
That true guard cells of the normal form are present in Prene-
lopsis, in addition to the remarkable accessory cells, is further
indicated by the similar conditions presented by other cretaceous
plants. A case in point is furnished by Androvettia statenensis
Hollick and Jeffrey. Fig. 9 is a photograph showing the general
features of the epidermis of the species. The cells are very thick-
walled and irregular in shape. The numerous stomata lack
the definite arrangement characteristic of Frenelopsis. The more
highly magnified representation given in fig. 10 shows the presence
of accessory cells around the stomata as before. In this case they
lack the conical projections of Frenelopsis, the opening having 4
uniform outline. The presence of true guard cells is strikingly
illustrated in the figure, the aperture appearing as a conspicuous
slit across the space surrounded by the accessory cells. Owing to
the good condition of preservation of this plant, the guard cells
are distinguishable in the majority of cases. Nevertheless,
poorly preserved specimens they have often been destroyed just
as in Frenelopsis. Fig. 11 shows two stomata from which the guard
cells have completely disappeared, although the accessory cells
are present in their normal condition.
Another cretaceous fossil possessing both true guard cells and
accessory cells is Brachyphyllum macrocarpum Newberry. Asection
parallel to the surface of the leaf of this plant is shown in fig. 12-
In each of the stomata the two guard cells are seen to be sur
rounded by four accessory cells.
The evidence herein adduced from the structure of the stomata
of modern conifers, from the conditions presented in fossils of the
same geologic age, and above all from actual observations both 10
section and surface views of Frenelopsis itself, appears to show con-
clusively that true guard cells are present in this genus, and that the
BOTANICAL GAZETTE, LIV PLATE V
5 THOMPSON on STOMATA 6
BOTANICAL GAZETTE, LIV PLATE VI
| THOMPSON on STOMATA AD
1912] THOMPSON—STOMATA OF CRETACEOUS CONIFERS 67
so-called guard cells are really the commonly occurring accessory
cells. The only recorded exception to the remarkably uniform
organization of the stoma in the Embryophyta thus disappears.
The writer is indebted to Professor JEFFREY for the material
used in this investigation, which was carried on under appoint-
ment as an 1851 Exhibition Science Research Scholar of the Uni-
versity of Toronto.
HARVARD UNIVERSITY
CAMBRIDGE, Mass.
EXPLANATION OF PLATES V AND VI
Fic. 1.—Frenelopsis occidentalis: stoma in surface view, showing the
rosette of projections; X 333.
Fic. 2.—The same: vertical section through a stoma, showing the pro-
jections mS stomatal cavity; X 250.
IG. 3.—The same: vertical section of another stoma, showing two guard
cells tis the accessory cells; 250.
Fic. 4.—The same: another stoma with distinct guard cells; X 250.
Fic. 5.—The same: camera lucida drawing of stoma from beneath, show-
ing two guard cells above the accessory cells.
Fic. 6.—Agathis bornensis: vertical section of base of showing two
guard cells sunken beneath conspicuous accessory cells; X 33
Fic. 7.—The same: section parallel to oa surface, ae stomatal
opening surrounded by four accessory cells; X
1G. 8.—The same: section parallel to the ist but deeper—below the
accent cells and including the two guard cells; X33
Fic. 9.—Androvettia statenensis: surface view of tiene: X 63.
Fic. 10.—The same: higher magnification, showing two guard cells below
accessory cells; X 250.
Fic. 11.—The same: stomata from which the guard cells have disappeared ;
X 250.
Fic. 12,—Brachyphyllum macrocarpum: section parallel to the surface,
showing accessory and guard cells; X125.
Sercrcnm ARTICLES
EDUARD STRASBURGER!
(BorN FEBRUARY 1, 1844; DIED May 10, 1912)
(WITH TWO PORTRAITS)
In the death of SrRASBURGER, professor of botany in the University
of Bonn, science has lost one of its greatest investigators. His publica-
tions, extending over nearly half a century, naturally give the impression
that he was a very old man, but
such was not the case, for he
was only in his sixty-ninth year,
and was still actively engaged
in research and teaching, when
the end came suddenly through
an attack of heart disease.
STRASBURGER was a native
of Russian Poland, and began
his education at Warsaw, study-
ing later at Bonn and at Jena.
He traveled extensively in
Europe, and in 1873, with
HakckEt, he visited Egypt and
the Red Sea, but most of his
vacations were spent in Italy,
on the Riviera. His wife died
several years ago, but his chil-
dren survive him. He was
devoted to his Sanity. was proud of his children, and during the long
period while Mrs. SrRASBURGER was an invalid, he always found time
to accompany her in her daily walk through the beautiful gardens of the
old Poppelsdorfer Schloss, once the palace of the Electors of Cologne,
but now serving as the botanical laboratory and home of the professor of
botany. With others also he was kindly and easy to approach, so that
™An account of StRASBURGER’s laboratory and work, written by Professor
J. E. Humpsrey, was published in this journal eighteen years ago (Bor. GAZ. 19
401-405, with portrait. 1894).
Botanical Gazette, vol. 54] 68
T912] BRIEFER ARTICLES 69
his students found in him not only a teacher, but also a sympathetic
friend, interested in their researches, but also interested in their welfare
after leaving his laboratory.
His first publications dealt with the ecsbayoligs of gymnosperms,
then with the more minute details of the life- -history of angiosperms. In
these researches he showed a profound grasp of the fundamentals of
comparative morphology and gradually turned more and more to the
study of the cell, until his laboratory became —— as the most
“ser eytolouical center in
the wo
He was a remarkable lec-
turer. Although a master art-
ist, he seldom used the chalk,
but presented his subject in
such vivid word pictures that
any further illustration seemed
unnecessary. His usual lec-
tures to students covered mor-
phology from the algae to the
flowering plants, and every
Friday he gave a lecture, open
to the public, upon some bo-
tanical subject of popular
interest.
In the research laboratory
he visited every student every
day, and always had some
helpful suggestion or criticism, but the student would learn on the first
ay that STRAsBURGER had no time to waste. This daily round, » in
which he might visit as many as eight investigators, seldom occupied
more than half an hour, but occasionally, after the usual laboratory
hours or on Sundays, he would come into the laboratory, when only
one or two students were present, and talk familiarly on various
subjects for an hour or more, He seemed particularly attached to his
American students. It was my privilege to know him rather intimately
at Bonn, and during the ten years which have elapsed since my return, a
Constant correspondence has continued the inspiration and helpfulness
received while at his laboratory. Some quotations from this correspond-
€nce will be of more interest than anything else one could write. In a
letter of June 29, 1910, he says: “I prize very highly the kindly recogni-
70 BOTANICAL GAZETTE (yoy
tion of my scientific efforts by my American colleagues. It is a great
pleasure to note the tremendous advances of our science in the United
States, and to be able to say to myself that in some measure I have been
responsible for it.”
the greatest interest is a letter of October 2, 1908, written in
response to a request for some data to be used in an historical seminar at
the University of Chicago.
LIEBER HERR KOLLEGE:
You overestimate my contributions! I myself am inclined to believe that
I have often failed and only in part attained the scientific ideal which hovered
before me. However, in the investigation of life everything is still in flux, the
solution of the problems lies in the distant future, and the best that can be said
of any one of us is that he was a necessary stage along the way to knowledge.
What gratifies me particularly is that in my lecture-room and laboratory I
have inspired competent, gifted men of high ideals to strive for the same goal
which hovers before me, and that my work shall continue to live in theirs.
Since you wish to know it, I was born on February 1, 1844. I studied
first at Bonn, where I gained technical skill under HERMANN SCHACHT, and at
the same time found a great stimulus in the lectures of JuLrus SAcHs, who at
that time was a teacher in the Poppelsdorf Agricultural Academy. The sudden
death of ScHacut made me decide to go to Jena to PRINGSHEIM, who had met
me in his visits to Scuacut, and who invited me to become his assistant. The
critical mind of PriNcsHErM reacted beneficially upon me, while my association
with Ernst HAECKEL soon made me enthusiastic over the great problem pre-
sented by CHARLES DARWIN.
My acquaintance with my ten years older teacher soon became friendship,
and I have to thank Ernst HarckeL that two years after my promotion in
Jena, when PRINGSHEIM retired, I was called to his place. I was then 25 years
old. I was never closely associated with Hormetster. Unfortunately, during
the latter part of his life, HormetstER became very sensitive and was angry
with me because in 1869 in my work on Befruchtung bei den Coniferen 1 sought
to prove that the “corpuscula” do not correspond to the embryo sacs of angio-
sperms, but are archegonia. HAaNsTEIN came to Bonn as professor after I had
already settled in Jena. In 1887 I came to Bonn as HANSTEIN’S successor.
ad been teaching in Jena for twelve years.
With hearty greeting, your very devoted,
E, STRASBURGER
In his correspondence with his colleagues, STRASBURGER never used
a typewriter, feeling that a typewritten letter indicated haste and lack
of respect. The following is a reproduction, slightly reduced, of a noble
paragraph from the above letter.
1912] BRIEFER ARTICLES 71
iS ae Kerra De
STRASBURGER felt keenly the attack made upon him on account of
his paper on graft hybrids. He felt it beneath his dignity to reply, but
in a letter of January 6, 1910, he says: “I had the position to defend
which I have held in regard to the réle of the nucleus in fertilization and
heredity, and which WINKLER threatened to overthrow. That alone
was responsible for my paper in the Berichte der deutschen botanischen
Gesellschaft.”
For some time he had known that his health was failing, but he had
continued to work, and his publications show that he was still in his
prime and that advancing years had only brought their experience and
Power without weakening his initiative or enthusiasm in research. At
the time of his death, he was deeply interested in the problem of the
determination of sex and had investigations under way bearing upon
this important subject, but was being delayed by another piece of work.
In a letter of March 5, 1911, he writes: —
Unfortunately, I have not got to my microscopic work this winter. A year
ago I saw myself necessitated to take part in a scientific publication of preten-
tious scope, bearing the name Kultur der Gegenwart, which is to present in
accessible form the whole field of science. The plan may be good in itself, but
I have often deplored that I allowed myself to undertake the work and that I
must devote to it, rather than to my own research, the few years of scientific
activity which still remain for me. Besides, I have not felt well this winter,
72 BOTANICAL GAZETTE [JULY
and in spite of the advice of my physician, have had to work hard. Day after
tomorrow I start for the Riviera and shall see whether I may not recuperate
a little.
At the present time a Festschrift is under way to commemorate
STRASBURGER’S seventieth birthday. A complete account of his life
and work will doubtless be published, but a brief notice is appropriate
at this time, and the words from his own pen will be appreciated by his
numerous pupils and friends. The photograph taken in his regalia,
while he was president of the University of Bonn, was given with
the injunction that it must not be shown in Germany nor published
anywhere during his lifetime. The other photograph was taken in
1892.
—CHARLES J. CHAMBERLAIN, The University of Chicago
CURRENT LITERATURE
BOOK REVIEWS
The Chicago textbook:
Of the three parts composing the Chicago Textbook of ety = Colleges
and Universities, “ Morphology” by CouLTEeR and “Physio y BARNES
appeared nearly two years ago, and were noticed in - etait while
“Ecology” by Cow Les, concluding the work, appeared in January and is now
before us.
However eagerly parts I and II were anticipated by all concerned with
botanical education, an even warmer welcome has been ready for part III,
because, while the former had predecessors, the latter has not. What, then,
are the characteristics of this first compendious textbook of ecology ? _ the
first place, as most botanists will notice with pleased surprise, the book is
primarily a description and analysis of the ecological factors, treated in connec-
tion with the principal organs—roots, stems, leaves, etc.—with which they are
most closely associated; while the synthetic phases of the subject—those
discussions of associations, formations, societies, etc., which have to come to
stand in the minds of most people as synonymous with the very word ecology—
are relegated to a single brief chapter. This is wise, because it is becoming
quite plain that the relative barrenness of synthetic ecology is a natural con-
sequence of the newness, crudeness, and deficiencies of our knowledge of
analytical ecology. In the second place, the book is a remarkably clear and
forceful presentation of its subject, the exposition, indeed, being in no wise
inferior to the high standard of the preceding parts, while occasional important
passages (e.g., the description of photosynthesis on pp. 525-526) are notably
effective. Furthermore, a striking quality of the book is completeness, but
it is a question whether in this feature a virtue has not been carried so far as
to constitute a fault; for so detailed is the treatment, and so obvious is the
intention to leave no important phase of the subject untouched, that the work
is carried out of the field of the textbook, in which rigid selection and propor-
tion are essential, into that of the handbook, where completeness is of course
a very first requisite. This view receives incidental confirmation from the
length of this part in comparison with the others, for it comprises no less than
479 pages, as contrasted with the 296 of part I, which covered all of morphology,
* COULTER, Barnes, and Cowtes, A textbook of botany. Vol. II. Ecology.
8vo, pp. 480. Jigs. 535. New York: American Book Co., 1912. $2.00.
* Bor. Gaz. 51:67. 1911.
73
74 BOTANICAL GAZETTE [JULY
including the whole range of the groups, and the 189 of part II, which com-
prised all of physiology. So gross a relative disproportion between bulk and
intrinsic content value, while unjustifiable from the textbook point of view
and prohibitive of the acquisition by a student of any such clear-cut and well
proportioned view of its subject as parts I and II afford, is perhaps allowable
on the ground of the genuine need for a first formulation of the material.
In the third place, the book displays the same wealth of well selected illus-
tration, and the same tasteful, even beautiful typography of the earlier parts.
And finally, so far as the accuracy of the fact-matter is concerned, it will
require a vastly larger knowledge of the material than the present reviewer
possesses to detect any considerable error either of statement or omission,
while such flaws as appear are too insignificant for mention. It is, in brief,
a distinctive, authoritative, foundational work, destined to take an immediate
place as an indispenable reference work for all concerned with the life-
phenomena of plants.
A remarkable feature of the book consists in its philosophy. This may
be summarized as a systematic antagonism to everything Darwinian. Under
the assumption that the language commonly in use to describe the relations of
plants to their surroundings, including such words as adaptation, adjustment,
storage, etc. (p. 487), mislead learners into a belief that plants act with an
even more than human forethoughtfulness (p. g50), the author attempts to
avoid all such expressions, visiting with especial condemnation anything of
teleological implication. But only a bogey of his own creating is at the
bottom of the author’s trouble. No students, in the reviewer’s experience,
if only half-decently instructed, ever gather any such notions. Besides,
Darwin himself, as to whose views, of course, there is difference of opinion,
but as to whose rationalistic habit of mind there is none, habitually uses
teleological language throughout his works without ever having been mis-
understood in this respect. However, Professor CowLEs is apparently not
an evolutionist, because, after expressly and repeatedly combating the idea
of a historical or causative adaptation, which he makes either an accident or
a psychological illusion, he replaces it by the idea of ‘mechanical causation i
(p. 487), that is, passive reaction to mechanical, physical, or chemical influences.
Now this idea carries the inevitable corollary that such responses must be
always the same in the same part under the same conditions, and that there-
fore they cannot be modified into anything else, any more than chemical
compounds can change the nature of their reactions to outside influences;
and without such possibility of change, no evolution, but only a kind of spon-
taneous creation, is possible. In his opposition to everything savoring of
adaptation, the author is led at times even to a distorted representation of
the views he opposes. Thus, no authors, that the reviewer can recall, and
certainly none of authoritative rank, have ever maintained any such naive
conception of adaptive response as is attributed to some of them, by implica-
tion, at the top of p. g50. Indeed, the author’s view of everything relating
1912] CURRENT LITERATURE 75
to adaptation is distinctly myopic, and the treatment of those subjects tends
to the dogmatic, not in language but in spirit. This very book seems to the
reviewer to show that whatever the deficiencies of the adaptation-selection
hypothesis, it still has to its credit a notable balance of reasonableness in
comparison with the proposed substitute.—W. F. GaNonc.
An elementary text
A new elementary text by BERGEN and CALDWELL’ attempts to meet the
growing demand for practical botany, which means the economic aspects of
plants. This demand arises not only from the interest of pupils in the “bread
and butter” side of science, but also from what is thought to be the greatest
need of that very large proportion of high-school students whose formal
education ends with the high school. There is no question that advantage
should be taken of interest and need, and the only question is as to whether
they are satisfied by a proposed course of study. Moreover, this question
can be answered only by experience. Many a public demand voices a real
need, and then the change comes to stay; and many another public demand
voices an imaginary need, and then the change soon passes into the limbo
of “ fads.’
The book before us has been handicapped in setting the task of meeting
a possible public need and at the same time meeting the artificial need of
entrance requirements imposed by colleges. As a result, the unifying motive
is lacking and the book becomes a mosaic rather than a definite pattern.
The field of previous texts is covered, and to this is added the economic phases
of plants, which compels a brevity of treatment in many cases that results
in obscurity. In spite of the divergent purposes and space limitations, the
book is a marked advance in the direction intended.
Some of the noteworthy features are: an introductory general survey of
plants in relation to man, and “the plant as a working unit” (pp. 23); ele-
— forestry (pp. 21); plant breeding (pp. 21); plant industries (pp. 30);
(pp. 11); leading families of flowering plants and their uses (pp. 35);
and especial emphasis upon plant diseases and methods of control. In a
practical botany of 513 pages, one is surprised to find no less than 214 pages
devoted to plant groups. However, economic significance has frequently
determined the selection of the forms discussed. With the exception of most
of the material treated under “The great groups of plants” (pp. 156-370),
the text has a decided flavor of elementary agriculture and might well serve
as a text in elementary agricultural botany, though such an important topic
as seed testing and selecting is conspicuous by the absence of any special
treatment. The numerous footnotes and references to literature should prove
both useful and stimulating, at least to instructors. The introduction of
’ BERGEN, J. Y., and CaLpweELt, O. W., Practical botany. pp. v-+545- figs. 381.
Boston: Ginn & Co., , IQII.
76 BOTANICAL GAZETTE [JULY
numerous new and well chosen cuts is refreshing. Unquestionably the book
is a valuable addition to elementary texts in botany and should find a wide
field of usefulness in the hands of trained instructors—LERoy H. Harvey.
MINOR NOTICES
Nature sketches.—The chief scientific value of Hancocx’s Nature
Sketches! is the large number of accurate and original observations upon
insects and other animals in relation to their natural environments. The
first chapter contains an unusually clear and simple discussion of problems
and theories of evolution. Insect and bird pollination, and the relations of
animals to flowers are discussed and beautifully and accurately illustrated,
especially in the second chapter, ws ae photographs, and colored plates
of examples from temperate Ameri e adaptations of insects, birds, and
flowers are discussed, and the aioe appears to be of the opinion that every-
thing is useful. It is unfortunate that the idea of adaptation should be intro-
duced without qualification into a popular work at a time when many botanists
and zoologists regard it as doubtful. The chapters on “Animal behavior’
and “Ecology” should have had less comprehensive titles. Though some-
what confused with faunistic geography, the first five pages of the chapter on
ecology are devoted to a good summary of some of the important facts of
genetic ecology. The lists of plant and animal habitats at the end of the
book give the habitat preferences of a number of Orthoptera, but contain few
elements of progress in ecological classification. The current classification
has not been followed.s In addition to its scientific value, the book is a good
introduction to many aspects of natural history for the lay reader.—
V. E. SHELFORD.
manuals.—The nature and purpose of the very interesting
Cambridge manuals of science and literature have been noticed in this journal.
At that time five volumes dealing with plants had been published, and now
two additional volumes have appeared: Links with the past in the plant world,
by A. C. Sewarp (pp. 142); Life in the sea, by J. JOHNSTONE (pp. 150). The
volumes are sold for one shilling each, and form for the general reader a readable
résumé of current scientific knowledge. The titles of the eight chapters of
Professor SEwarp’s volume will give a better conception of the contents —
does the general title. They are as follows: “Longevity of trees, etc.”
“The geographical distribution of plants”; ‘The geological record”; «Pres:
ervation of plants as fossils”; “Ferns, their distribution and antiquity”;
“The redwood and mammoth trees of California”; ‘The Araucaria family”’;
4 Hancock, Josern L., Nature sketches in temperate America. 8vo. xviii+451-
pls. 12. figs. 215. Chicago: A. C. McClurg & Co. tor.
5 PEARSE, in Science 34237. 1912, is mistaken in this matter.
6 Bot. Gaz. 522234. 1911.
1912] CURRENT LITERATURE rie
“The maiden hair tree.” The American publisher is G. P. Purnam’s Sons
of New York.—J. M
North American Flora.7—Vol. VII, part 3, continues the treatment of
the Uredinales and contains the Aecidiaceae from Prospodium to Dichaeoma
by JosepH CHARLES ARTHUR, the text for the genus Gymnosporangium being
contributed by FranK DUNN KERN. One new genus (Argomyces) is proposed,
which has a geographical distribution from New Mexico and Texas through
Mexico and the West Indies to South America, and is represented at present
by four known species. Further new species are characterized in the following
genera: Earlea (1), Kuehneola (1), Spirechina (x), and Xenodochus (1).—
J. M. GrREENMAN.
NOTES FOR STUDENTS
Variation curves.—Several years ago papers dealing with variation
in the number of parts of flowers, flower heads, inflorescences, etc., were of
frequent appearance. As the novelty of the method disappeared, the number
of contributors to the knowledge of such variations has decreased, but, as is
usually true in such cases, the value of the contributions has correspondingly
improved. Several recent studies in this field are of exceptional interest.
_ Vocter’ gives a large number of counts of ray flowers in Chrysanthemum,
Boltonia, and Senecio. In Chrysanthemum Parthenium he found a curve having
the mode on 21 when the plants were grown on well-manured soil, and on 13
when grown on infertile soil, the curves being strongly skew in each case
toward an intermediate point, the mean values lying between 14 and 19.
These results agree essentially, therefore, with those of KiLEBs? on Sedum
Spectabile. In Boltonia latisquama the ray flowers have a wide range of varia-
tion (39-81), with the summit of the curve near 55. Three different plants
were separately counted in three successive years, and although the different
Seasons differed considerably, there was no corresponding change in the number
of ray flowers. One of these plants had each year the mean number approxi-
mately 57, another approximately 54. These permanent differences are proba-
bly not to be attributed to genotypic differences in the plants, however, as they
originated from a common stock by vegetative division. In Senecio alpinus
a count of over 3000 heads from two different localities in three different years
Save in every case a nearly monomodal curve with the mode on 19, thus con-
vincing the author of the limitations of Ludwig’s law that the maxima of such
h American flora. Vol. VII, part 3, pp. 161-268. The New York
Botanical Garden. April 15, 1912.
*Vocter, P., Variation der Anzahl der Strahlbliiten bei einigen Kompositen.
Beih. Bot. Centralbl. 253387-396. IgIo
° Kuss, G., Studien iiber Variation. Arch. Entwick.-Mech. Organ. 24: 29-113.
1907,
78 BOTANICAL GAZETTE [JULY
variation curves fall upon the numbers of the Fibonacci series, 2; 3, §, $2
etc., ota low multiples of them, or on the similarly constituted “Trientalis-
series,” 3, 4, 7, 11, etc., and their low multiples. The latter series was dis-
covered by Lupwic in Trientalis, whence its name. VOGLER” had found
earlier that the modes in the number of umbellary rays of Astrantia major fall
upon members of the Fibonacci series when only the primary umbels are
included, but in the secondary umbels the modes are on the Trientalis series.
More recently the same author™ has reported on the number of ray flowers in
Arnica montana, Buphthalmum salicifolium, Eupatorium molle, Aster novi-
belgii, Senecio erucifolius, and Chrysanthemum Parthenium. Several of these
species gave well-marked modes on the Fibonacci numbers, but in other collec-
tions of data from the same species the mode occurred not infrequently on some
quite unrelated number. For example, in Arnica montana a collection from
Rigi, Switzerland, in 1908, showed modes on 13, 16, and 21, while heads of the
same species collected the next year at Klosters presented a well-developed
mode on 11 and only a slight indication of a mode on 13. Later analysis of this
case showed that the terminal heads give modes on 13 and 16, while secondary
heads give modes on 11 and 14, the latter numbers bearing the same relation
to the Trientalis series that the former do to the Fibonacci series. This whole
problem as to the position of the modes in variation curves of ray flowers, and
other organs which are related more or less definitely to the phyllotactic
spiral, is still unsolved, though it is evident that the Fibonacci series supplies
the modal numbers in many cases, and that other equally definite series are
followed in other cases. It is very rare that the number of variates used by
investigators is sufficiently great to establish with any considerable degree of
probable correctness these relatively superficial features of the curves. RITTER
has gone to the length of asserting that non-phyllotactic variates among plant
organs have their modal numbers also related to the Fibonacci or Trientalis
series. He even contends that this is true of graduated variates. In support
of this view he tabulates* a rather meager series of measurements of
width and length of leaves and leaflets of Stellaria media, Oxalis Acetosella,
Lysimachia nummularia, Hypericum perforatum, Caragana arborescens, Rosa
canina, Medicago sativa, Symphoricarpus racemosus, Fragaria vesca, and Cytisus
Laburnum, and the width and length of fruits of Alnus glandulosa, Rosa canina,
Quercus Robur, and Q. sessiliflora. He believes that the measurements of
surfaces, such as leaf blades, give modes related to the square roots of the
Fibonacci numbers, namely, on 10)/1, 10]/2, 10])/3, 10)’ 5, 10V 8, etc.
* VocLeR, P., Variationstatistische Untersuchungen an den Dolden von Astrantia
major. Beih. Bot. Centralbl. 24:1-9. figs. 6. 1908.
Voc P., Neue vrata Untersuchungen an Compositen.
Jahrb. sis Gallischen Naturwis. Gesells. 1910:1-32. 1911.
G., Uber discontinuirliche Niue) im Organismenreiche. Beih. Bot.
Centralbl. map 1909.
1912] CURRENT LITERATURE 79
and that in tri-dimensional material such as fruits, the modes are related in
similar manner to the cube roots of the Fibonacci numbers. The absurdity of
such a view will be obvious when it is considered that nature takes no note of
such arbitrary units of measure as the millimeter and centimeter, and that the
choice of any other unit of measure would place the modes on other values.
VOGLER shows by a much more extensive series of measurements of leaflets
of Cytisus Laburnum that while the curves are multimodal, the modes can not
by any sort of manipulation be made to fit the Fibonacci series.
In another paper, VOGLER™ performs an important service by summarizing
the statistical studies which have been made upon the heads of Compositae and
the umbel rays of the Umbelliferae, together with a few of the more important
investigations upon the flowers and inflorescences of other species. The list
of Compositae includes 45 species and of the Umbelliferae 10 species. The list
gives not only the names of the species and the particular organs studied, but
also states the number of counts upon which conclusions regarding the several
species have been based, the apparent modes, and references to papers in the
appended bibliography in which the results are recorded. This bibliography
contains 63 titles.
E BRUYKERS makes an extensive study of variation in the umbels of
Primula the motive for presenting a discussion of the entire subject of statistical
variation. This simple and concise presentation of the subject should occupy
for Dutch readers a place similar to that held by JoHANNSEN’s” discussion for
readers of German. It is not necessary here to consider the general treatment
of the subject of variation as given by DE BruYKER, but only the new results
relating to Primula officinalis, P. farinosa, and P. elatior. The modal numbers
of flowers in the inflorescences of these three species fall with considerable
regularity upon the numbers of the Fibonacci series, but collections taken at ~
different parts of the season show a gradual decrease in the average number of
flowers per inflorescence as the season progresses. Plants growing in a favor-
able environment had the mode on 5, and in less favorable ones on 3. The
similarity of results in collections from good and bad surroundings, and in
early and later parts of the season, convinces the author of the correctness of
the interpretation of the gradual fall in mean number of parts during the
OGLER, P., Die Variation der Blattspreite bei Cytisus Laburnum L. Beih.
Bot. Centralbl. 27: 391-437. figs. 12. 1911.
™ VoLcER, P., Probleme und Resultate variationstatistischer Untersuchungen an
Bliiten und pate Jahrb. St. Gallischen Naturwis. Gesells. 1910:33-71.
IgIt.
*s DE BruykeEr, C., De statistische methode in de plantkunde en hare toepas-
singen op de studie van den invloed der levensvoorwarden. pp. 226. figs. 33. Gent:
A. Siffer, 10
%6 JOHANNSEN. W., Elemente der exakten Erblichkeitslehre. pp. vi+516. Sigs. 31.
Jena: Gustav Fischer. 1909.
80 BOTANICAL GAZETTE [JULY
season, which attributes it to a change of nutrition, an interpretation which was
given independently by MacLeop and the reviewer about ten years ago. The
polymorphism shown by the multimodal curves is interpreted by DE BRUYKER
as due to differences in nutrition acting in conjunction with a discontinuous
mode of development, through which the new organs tend to be added in
groups instead of singly. The same explanation or one essentially similar is
applicable to other multimodal variation curves, the series of modes being
determined by the manner in which each succeeding group of organs added is
related to the preceding group or groups.
E BRUYKER recognizes nine series of modes for multimodal variation
curves. These are as follows: (a) the powers of 2 (2, 4, 8, 16, etc.), as in the
peristome teeth of mosses; (b) multiples of 3 (3, 6, 9, 12, etc.), as number of
flowers in Lonicera caprifolium; (c) multiples of 4 (4, 8, 12, 16, etc.), as in the
number of flowers per umbel in Cornus Mas; (d) multiples of 5 (5, 10, 15, 2
etc.), as in the number of stamens in Pyrus communis; (e) the rie
Ludwig series (1, 2, 3, 5, 8, [10], 13, [16], etc.), as in many Compositae, Umbel-
liferae, etc.; (f) the Trientalis series (1, 3, 4, 7, 11, 18, etc.), as in Trientalis,
secondary umbels of Astrantia major, lateral heads of Arnica, etc.; (g) Car-
damine series (2, 5, 8, 11, 13, 16, 19, 22), as found by VocLeR for the number
of flowers in Cardamine pratensis; (h) the odd series (1, 3, 5, 7, 9, ete.), as in
number of leaflets in imparipinnate leaves, etc.; (i) the even series (2, 4, 6, 8,
etc.), as in paripinnate leaves, rows of grains on ears of maize, etc
By selecting for higher number of rays in Calliopsis bicolor, under conditions
of high nourishment, DE BRUYKER was able to secure a strain of this species,
by far the largest number of whose heads had 13 rays, though the material with
which he began selecting gave a very high percentage with only 8 rays. This
result corresponds with that of DEVriEs with Chrysanthemum segetum. The
sensitive period for the influence of nourishment on the number of ray flowers
was investigated in Chrysanthemum carinatum, and this period was observed to
close four or five weeks before the opening of the heads. Der BRruyKER’s work
closes with a succinct statement of the principal results of the author’s investi-
gations on Primula elatior, Chrysanthemum carinatum, C. segetum, Calliopsis
bicolor, Scabiosa atropurpurea percapita, rye, barley, and wheat. The bibliog-
raphy contains references to a few more than roo papers dealing with the subject
of variation and its statistical study, and a full index is added.
NIEUWENHUIS” has studied the changes in the variations and in the mean
values of the number of ray flowers in nine species of Compositae from the
beginning to the end of the flowering season. He finds in seven of these species
an essential agreement with the behavior found by the reviewer™ in Aséer
7 NrEUWENHUIS, M., Die Periodicitat in der Ausbildung der Strahlbliiten bei den
Kompositen. Recueil Trav. Bot. Néerl. 8: 108-181. figs. 23. 1911.
8 SHULL, G. H., Place-constants for Aster prenanthoides. Bort. Gaz. 38:333-375-
1904.
1912] CURRENT LITERATURE 81
prenanthoides. The characteristic periodicity curve of mean values in these
species rises quickly to a maximum in the early part of the season, after which
there is a much more gradual decline until the end of the season. Only in
Melampodium divaricatum and in Cosmos sulfureus was there no essential change
throughout the season, the former species having a single mode on 10 with the
mean slightly above 10 in every collection made, and the latter species pre-
senting a similar constancy, having at all times a half-curve, falling steeply
from a strong mode on 5 only to higher values. In most of these species the
modes were on the Fibonacci numbers; and while the changes in mean values
were gradual and continuous, the appearance of modes on intermediate num-
bers was relatively rare. In Anthemis Cotula 11 and 9 appeared as transition
modes between 13 and 8; 9 also appeared momentarily in Zinnia Haageana,
Z. tenuiflora, and Laya platyglossa; and 11 and 12 in Sanvitalia procumbens.
In three heterocarpous species, Dimorph ies oe Laya platyglossa, and
Sanvitalia procumbens, the plants, grown from the s of see oduced
essentially like variation curves. The same te a was true of plants grown in
ifferent years and in different environments, the modal numbers and char-
acteristic slopes of the periodicity curves remaining unchanged for the par-
ticular species, though the mean values were considerably modified.—Geo.
H. SHutt
Roots of Psaronius.—Since the removal of the great mass of the
marattiaceous plants of the Paleozoic to the seed plants, more critical attention
has been given to Psaronius as the sole evidence of the existence of the Marat-
tiaceae at that early period. Among the structures differentiating Psaronius
from modern Marattiaceae, the most striking is the difference in the location
of the secondary roots in relation to the stem. In the modern representatives
of the family these roots bore their way for a considerable distance through the
cortex of the stem before they penetrate to the surface. At all points in their
course they are sharply marked off from the cortex by remnants of broken-
down cells. In Psaronius they form a wide zone in the cortex of the stem in
which there are no remnants of leaf traces or leaf scars, and no sharp distinction
between the root cortex and the parenchyma in the interstices between the
Toots. STENZEL’s explanation of this root layer as homologous with the outer
cortex of the Marattiaceae has passed current without question until the last
ten years. In 1902 FARMER and Hixu suggested that the parenchyma in the
interstices of the roots of Psaronius might be of the nature of hairy outgrowths
rather than cortical parenchyma of the stem.
The question thus raised has been attacked by Sotms-LauBacH® with
convincing results. He worked cheifly with thin sections of fossils (P. Haidin-
geri) from Manebach, supplemented by material from the Museum of Rio
*? Sotms-Lausacn, H. GRraFEN 2U, Der tiefschwarze Psaronius Haidingeri von
Manebach in Thiiringen. Zeitschr. Bot. 3:721-757. figs 7. 1911.
82 BOTANICAL GAZETTE [JULY
Janeiro. He finds that, unlike the modern Marattiaceae, Psaronius has a thin
cortex bounded on the outside by a massive hypodermal sclerenchyma layer.
From the outer region of this sclerenchyma layer or from the epidermis strands
of tissue develop by a secondary activity of the cells, giving rise to a clothing
of multicellular hairs on the surface of the stem. Where the secondary roots
make their way through the cortex and sclerenchyma layer, they are limited,
as in modern Marattiaceae, by a definite epidermis and by a zone of disinte-
grated cortical cells. But after they have penetrated the sclerenchyma layer,
no such clearly marked boundary is perceptible, for here the roots pass down-
ward among the multicellular hairs on the outside of the stem. They are con-
sequently imbedded in the hairs which form a filling tiavie between them,
closely applied to the stemward sides of the roots. Then, in turn, the hypoder-
mal layer of the cortex of the roots starts into activity. The resulting cells
are few on the inner surface of the roots, where the hairs from the stem are in
contact with them, while on the outwardly turned face they develop outgrowths
similar to the multicellular hairs of the stem. These in turn make an imbedding
layer for younger roots whose origin is higher in the stem, and which grow
downward over the root surfaces as the first roots grew over the stem. While
hairs of the stem fill the crevices between the first roots and are soon over-
wn by them, similar outgrowths from the roots fill the spaces between the
successive layers of roots. Each system of hairs stops its growth in so short a
time that a meristematic part of the tissue can never “ detected. No hesaseiek
ing of the filling tissues appears, because of the cons
the increase in the circumference of the stem and the number of cell rows in the
filling tissue, due to the increase in the number of points of origin.
If it were possible to follow a root throughout its course, it would be found
to be organized in three parts: a proximal part, in which it breaks its way
through the cortex of the stem; a middle part, applied to the filling tissue
arising from the stem; anda distal part, in which the subepidermal cortical
tissue develops. The so-called ‘‘inner” and “outer’’ roots of Psaronius
illustrate the two last mentioned portions
In an attempt to find whether this waeilinr development of the outer cortex
is present in plants related to Psaronius, Soums-LAUBACH examined a stem of
Xylopsaronius. Though its poor state of preservation made definite con-
clusions impossible, the presence of the root of another plant between the
sclerenchyma layer of the stem and the inner roots is strong evidence of a
esemblance. In confirmation of this, ScuitisteR® has shown complete cor-
respondence between a well-preserved root system of Xylopsaronius and
Psaronius. The tissue formerly interpreted as secondary xylem in the root of
Xylopsaronius is in reality secondary filling tissue originating from the cortex
like that described in Psaronius by Soums-Lausacu. His photomicrograph of
20 ScHUSTER, J., Xylopsaronius, der erste Farn mit secundirem Holz? Ber.
Deutsch. Bot. Gels. 29:545-548. 1911.
Tgi2] CURRENT LITERATURE 83
the stem is strong evidence in support of the interpretation of the filling tissue
as peculiar outgrowths. Nothing comparable to such multicellular hairs on
roots has been found in present ferns, although it is possible that examination
of tropical tree ferns may reveal traces of similar structures—Grace M.
CHARLES
The development of Pyronema confiuens.—Believing that the alterna-
tion of generations has not yet been satisfactorily worked out in any fungus,
CLAUSSEN* has completed an extensive cytological and morphological study
of the development of Pyronema confluens, a form already investigated by
Harper”. The spores germinate immediately on being discharged from the
ascus. He finds that under favorable conditions any cell of the fungus may
develop into a complete plant. In material grown on agar at 20° C. in direct
sunlight, he finds that the vegetative mycelium is produced in 1-2 days; the
fruit bodies begin to form in 2-3 days; fertilization occurs in 3-4 days and the
first ascogenous hyphae appear; after 5 days the recurved tips of the ascogenous
hyphae are observable; young asci may be found on the sixth day, at which
time 1, 2, 4, and 8-spored asci are present. In cultures under these conditions
the fungus completes its development in 7-8 days. CLAUSSEN observed that
the younger stages of the fruit bodies often arise from dichotomously branched
aerial hyphae, so that they are often stalked. His observations as to the origin
of the sexual organs agree in general with the earlier descriptions of DE Bary
and of Kratman.%* The hyphae, which bear the ascogones, and those which
bear the antheridia, may arise from the same mycelial thread; the fungus,
therefore, is homothallic.
The mycelium consists of multinucleate cells. Protoplasmic streaming
was observed in the hyphae, indicating that there is a pore in the cross-walls,
connecting the contents of adjacent cells. The hyphal branches which bear
the sexual organs are always multinucleate. CLAUSSEN is unable to determine
whether or not nuclear division occurs in the ascogone and in the antheridium
before fertilization. So far as he is able to discover, the nuclei in the se
organs are exactly alike. When the sex organs are mature, he observes that
the nuclei increase in size, but that there is a more marked increase in the size
of the nuclei of the ascogone. Certain nuclei in both male and female organs
degenerate before the sexual act. The phenomena concerned in the fusion of
the antheridium with the trichogyne, the passage of the male nuclei into the
A
**CLAussEN, P., Zur a oe Ammon Lee
confluens. Zeitschr. Bot. 4:1-64. pls. 6. figs. 13.
* Harper, R. A., Sexual reproduction in pa confluens and the morphology
of the ascocarp, Ano. Botany 14: 321-400. 190
* DE Bary, A., Ueber die Frchtentwickung der Ascomyceten. Leipzig. 1863.
* Kratman, O., Zur Entwicklungsg Ascomyceten. Acta Soc. Scient.
Fenn. 13: 29-40. 1883.
84 BOTANICAL GAZETTE [JULY
trichogyne and thence into the ascogone, is essentially as has been described by
Harper and others. After the sexual act is completed and the trichogyne is
again cut off from the ascogone, many nuclei were observed in the ascogone in
pairs. On account of the slight difference in size of the paired nuclei and of
the nucleoli; he believes each pair consists of a male and female nucleus. A
fusion of these paired nuclei does not occur in the ascogone, but they enter the
ascogonous hyphae in pairs. Brown’ holds that there is no fusion of the
exual nuclei in the ascogonium. He holds that an appearance quite like fusion
results from division of the nuclei, the daughter nuclei remaining closely
associated.
The ascogenous hyphae were observed to develop in several different ways.
Whatever the method of their development, CLAUSSEN believes that the sexual
nuclei and their progeny formed by conjugate division remain entirely distinct.
A pair of each of the nuclei finally enters the young ascus, where they fuse to
form the primary ascus nucleus. CLaussEN finds it difficult to make out the
structure of the fusion nucleus of the ascus. He is convinced that the first
division of this nucleus is heterotypic, and finds a synaptic contraction and a
diakinesis, in which there are about 12 bivalent chromosomes. At no point in
nuclear division has he been able to distinguish central bodies with certainty.
In the second and third divisions of the ascus nuclei he fails to find a synaptic
contraction or a diakinesis stage. The number of chromosomes in these
ivisions is about twelve. The process of spore formation and spore delimi-
tation is Mb, 8 as described by
g to CLAUSSEN, the spore, mycelium, and sexual organs constitute
the Sek while the ascogenous hyphae represent a sporophyte not
rply separated from the gametophyte. The ascus is a spore mother cell.
The sporophyte, instead of having nuclei with double chromosome numbers,
contains male and female nuclei in pairs, which divide by conjugate division.
The nuclear divisions in the ascus, except the first, have no significance in the
alternation of generations in this fungus.—J. B. OVERTON.
Cytology of Laboulbeniales.—In a short introductory account based
on the results of his studies of the cytology of a number of forms of the
Laboulbeniales, Faui* gives the general outlines of the morphology of this
group. The spores in the earliest stages of their formation are uninucleate,
but before the spore is mature the nucleus divides and a septum is formed,
dividing the spore into two cells. In Amorphomyces alone the septum is not
formed and the nucleus degenerates. The cells of the thallus are character-
istically uninucleate, but after the thallus has completed its growth some of the
*s Brown, W. H., Nuclear phenomena in Pyronema confluens. Johns Hopkins
Univ. Circ. 6242-45. 1909.
% FauL, J. H., The cytology of the Laboulbeniales. Ann. Botany 25:649-654-
Igit.
1912] CURRENT LITERATURE 85
larger cells become multinucleate. The nuclear divisions are mitotic through-
out. The antheridia in all cases are uninucleate. In the forms with exogenous
antheridia the uninucleate spermatia arise as branchlike outgrowths from the
antheridia. It is probable that the antheridial nucleus divides repeatedly to
furnish nuclei for the successively formed spermatia. In the forms with
endogenous antheridia, the antheridial nucleus divides and the sperm nucleus
is pushed out by the spindle fibers toward the opening of the antheridium
through which the spermatia are discharged. The spermatia consist of the
relatively large nucleus, apparently surrounded by only a little cytoplasm,
and the protoplasmic membrane. The antheridial nucleus divides repeatedly
to form successive sperm nuclei which are ejected by the spindle fibers in the
peculiar manner descri
The origin of the binucleate state of the carpogenic cell was made out
only in Laboulbenia chaetophora, which has no antheridia. In the other forms
neither the entrance of the sperm nucleus into the trichogyne nor its migration
through the trichophoric cell has been observed. In Laboulbenia chaetophora
the nuclei of the trichophoric and the carpogenic cells divide, and one nucleus
from each pair ultimately constitutes a member of the pair in the carpogenic
cell. From the carpogenic cell the ascogonium and ascogenous cells are formed
after a series of conjugate nuclear divisions. Asci bud off directly from the
binucleate ascogenous cells. The subsequent processes of nuclear fusion in
the ascus and spore formation differ in no essential detail from the analogous
Processes among the Ascomycetes with which the Laboulbeniales are usually
classed.
The conclusion drawn by the author from the cytological study of the
Laboulbeniales is that they belong to the Ascomycetes, and more particularly,
on account of the possession of a perithecium, to the Pyrenomycetes. The
phenomena occurring in the ascus appear to lend some support to this classi-
fication, but the author’s attempt to homologize the perithecium of the Laboul-
beniales with that of the Pyrenomycetes would seem to need further support.
Thus far the unique development of the perithecium of the Laboulbeniales
has no known analogies among the Ascomycetes.—H. HASSELBRING.
Sexuality in mosses.—Marcuat,” in a study of sexuality in mosses, makes
a comparison of a dioicous species, Bryum caespiticium, with a number of synoi-
Plants, the other half produce archegonial plants. Fertilization produces a
bisexual sporophyte and the sex characters are separated in the reduction divi-
sion. Consequently two members of the tetrad are always male and two
female, as has actually been shown in Sphaerocarpus. In synoicous forms the
77 MARCHAL, Ex., La sexualité chez les Mousses. Bull. Soc. Roy. Belgique 47:
277-285. 1911
86 BOTANICAL GAZETTE [JULY
gametophores from protonemata produced by spores, as well as those from
secondary protonemata rising from the stem, leaves, and even from the wall
cells of antheridia and archegonia, are always bisexual, and the sex characters
are not separated until the last division of the spermatogenous and the oogenous
ells. The sex characters are united by fertilization and not separated in the
tetrad. Therefore in dioicous mosses the sex characters are separate in the
spores, protonemata, gametophores, sperms, and eggs, but not in the sporo-
phyte; in synoicous mosses the sex characters are separate only in the egg and
sperm.
ARCHAL is able to induce apospory in the capsule of Bryum caespiticium.
Gametophores rising from an aposporous protonema are always synoicous, but
the eggs are never fertilized. He concludes that dioicous mosses which have
become synoicous through apospory are irremediably sterile. In the synoicous
Amblystegium serpens apospory was also induced, and the resulting gameto-
phores produced eggs capable of being fertilized. In the 4x sporophytes from
these fertilized eggs, apospory was again induced, but the 4x leafy shoots,
although exceptionally vigorous, have as yet remained persistently sterile. The
same results were obtained in other synoicous species, Amblystegium es
Barbula muralis, and many others which the author does not name. He st
that Ephemerum serratum and Funaria hygrometrica are synoicous. ie
SPEER, working in the Hull Botanical Laboratory, first showed that the latter
species is occasionally synoicous. MarcuAt is at present studying a sterile
synoicous Brywm atropurpureum which he believes is a natural aposporous
derivative of the common dioicous form.
There are no illustrations, and no definite information as to how the
presence of 2x and 4x numbers in the aposporous derivatives were proved; nor
are the methods for inducing apospory and for continuing the cultures given in
detail. It is an admirable piece of much-needed research, but the lack of a
definite and detailed statement of methods is a very unfortunate omission»
since many investigators look with suspicion on the work of those who are
secretive as to methods when fundamental problems are concerned.—W. J. G.
LAND.
Phytomyxaceae.—Scuwartz, who has recently made several contribu-
tions to our knowledge of the oneniltis slime molds, gives an account®
of another form which he found on the roots of Poa annua and other grasses.
The organism, to which he gives the name Sorosphaera graminis without,
however, adding a formal diagnosis, is closely related to S. Junci, which the
author discovered in the roots of sedges. The organism was found most
abundant on plants whose roots were hypertrophied by eelworms. It is not
usually found, however, in the swollen parts, nor does the organism itself
produce any form of hypertrophy. The life-history of S. graminis does not
28 Scuwartz, E. J., The life-history and cytology of Sorophaera graminis. Ann.
Botany 25:792-797. 1911.
1912] CURRENT LITERATURE 87
differ from that of S. Junci, but some of the stages appear to be more easily
observable in S. graminis. The youngest stages are uninucleate amebae.
These fuse to form plasmodia which grow until they occupy the entire host
cell. The nuclei of the growing plasmodia all divide repeatedly and simul-
taneously in the manner described for other members of the Plasmodiophora-
ceae. At the close of the vegetative stage the akaryote or chromidial stage
begins. The nuclei lose their contents, leaving only vacuoles in their place.
Within these vacuoles apparently fresh nuclei are organized. ese undergo
mitotic divisions, after which the plasmodium is broken up by cleavage into
small uninucleate masses which become the spores. Under the classification
of Marre and Tison, this form would be placed in their genus Ligniera, which
includes those species of the Plasmodiophoraceae which lack the schizogenous
stage and do not cause swelling on their host plants.—H. HassELBRING.
Zygopteris.—Scorr® has studied sections of a new specimen of Zygopteris
Grayi, and finds that it is an Ankyropteris, as BERTRAND had pointed out, on
the basis of the presence of peripheral loops on the leaf trace. The vascular ,
cylinder of the stem (a 5-rayed star in section) is regarded as ‘“‘a highly elabo-
rated protostele,” there being at present no evidence for the existence of a true
pith in any member of the group. This is certainly a simpler spear
of the pithlike region with interspersed tracheids than to regard the cy
as a “condensed” polystelic structure. It would be even simpler to panei
“highly elaborated,” and to call the cylinder an incomplete protostele. The
problematical and abundant “aphlebiae” are found to be “m sal
pinnae of the leaf, as shown by the structure and mode of origin i their vascular
Strand.”—J. M. C.
Effect of temperature on respiration.—K uljPEr,® while at the Buitenzorg
laboratories, determined the CO, production by seedlings of Arachis hypogaea
and Oryza sativa at various temperatures from 15° C. to 50°C. He finds that
the effect of temperature on respiration of the tropical plants studied is the
same as on plants in the temperate zone. But the “critical temperature”
(temperature at which a high respiratory intensity is maintained for a con-
siderable time) of Arachis hypogaea is 5°—10° higher than that previously found
for Pisum and Lupinus. Kutyrer thinks this difference is due to their sur-
roundings. The mean temperature at Java is about 1o° higher than the mean
temperature of the vegetation period of the temperate zone.—Sopuia H.
CKERSON.
* Scorr, D. H., On a paleozoic fern, the Zygopteris Grayi of Williamson. Ann,
Botany ae 9-9 as 1-5. fig. 1. 1912
* Kurjper, J., Einige weiteren Verwurhe iiber den Einfluss der Temperatur auf
. Atm der héheren Pflanzen. Ann. Jard. Bot. Buitenzorg II. 9245-54. pls. 6,7.
* Bor. Gaz. 50: 233. 1910.
88 BOTANICAL GAZETTE [JULY
Doubling of embryo sac.—CompPrTon? reports an interesting situation in
trated by a pollen tube, and each containing a two-celled embryo. He calls
this “a curious example of duplicity.”” The closing statement is worth remem-
bering: “‘The fact that two pollen tubes should enter and fertilize an ovule
which had developed two embryo sacs can hardly be a mere coincidence;
rather it would seem to indicate a quantitative relation between embryo sac
and pollen tube in the matter of chemotaxis, two embryo sacs excreting suf-
ficient of the chemotropic substance to attract two pollen tubes.” —J. M. C.
edling structure of Centrospermae.—Hirt and DrFRaAINe® have
iced the results of an extended survey of the transition phenomena of
the seedlings of Centrospermae. The “theoretical considerations” are to be
presented later, but in the present paper there are indications of what they may
be. The families presented, through abundant representatives, are Portu-
lacaceae, Caryophyllaceae, Amarantaceae, Chenopodiaceae, Phytolaccaceae,
Aizoaceae, and Nyctaginaceae. The authors state that “no very striking
results” were obtained, and that the chief interest is connected with the features
of the last-named family.—J. M
Fall of leaves.—Based upon a mass of data collected largely from
the literature, Comprs* shows that the conception of Sacus regarding the
migration of substances at the time of leaf fall is no longer tenable. The
substances that do not disappear from the leaves, as well as those that accumu-
late in them before their fall in the autumn, are not to be considered a priori
as substances non-utilizable or toxic for the plant containing them. The
fallen leaves contain an important eragie of substances that would have
been utilizable by the plant.—Cuas. O. APPLEMAN.
Morphology of Viola.—Miss Butss35 has studied five species of Viola
with reference to the structures connected with the embryo sac. The hypo-
dermal archesporial cell, the tapetal cell, the linear tetrad, and all the ante-
angiosperms. Double fertilization was observed in V. cucullata. “There
is no suggestion of a suspensor,’”’ and es niente surrounded by a solid mass
of endosperm, is bright green.—J. M
# Compton, R. H., Note on a case of doubling of embryo sac, pollen tube, and
embryo. Ann. Botany 26: 243, 244. 1912
3 Hit, T. G., and DeFrarne, Eret. On the seedling structure of certain
sa i Ann. Botany 26:175-199. figs. 15. 1912.
BES, Raout, Les opinions actuelles sur les phenoménes physiologiques qui
Pea ace: la chute des feuilles. Rev. Gén. Bot. 23:129-264. I91I.
35 Briss, Mary C., A contribution to the life history of Viola. Ann. Botany
26:155-163. pls. 17-19. 1912.
THE
BoTANICAL GAZETTE
August 1912 45
Editor: JOHN M. COULTER
CONTENTS
Spermatogenesis in Equisetum Lester W. Sharp
The Primary Color-Factors of Lychnis and Color-Inhibitors
of Papaver Rhoeas George Harrison Shull
Contributions from the Rocky Mountain Herbarium. XI
Aven Nelson
Beneficial Effect of Creatinine and Creatine on Growth |
J. J. Skinner
Briefer Articles
A Note on the Generations of Polysiphonia
George B. Rigg and Annie D. Dalgity
Current Literature
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Edited by JOHN ME CouLTER, with the assistance of other members of. the ’ botanical staff of the
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Issued August le, 1912
‘Vol. LIV. : CONTENTS FOR AUGUST 19132 24 Be?
"SPERMATOGENESIS IN EQUISETUM. CONTRIBUTIONS FROM THE Hutt Botantcat LABORA-
158 (WITH PLATES VII AND vil). Lester W. Sharp - 89
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VOLUME LIV NUMBER 2
i ERE
BOTANICAL GAZETTE
AUGUST 1972
SPERMATOGENESIS IN EQUISETUM
CONTRIBUTIONS FROM THE HULL BOTANICAL LABORATORY 158
LESTER W. SHARP
(WITH PLATES VII AND VIII)
Historical résumé
The cilia-bearing organs of the motile cells of plants have formed
the basis of a number of researches during recent years. In the
majority of cases in which the bearing of the results has been given
consideration, the discussion has centered about the morphological
nature of these organs, and in this discussion a very prominent
place has been taken by the centrosome.
Among the earliest investigations in this field were those of
STRASBURGER (78) on the algae. During the development of the
"Swarm spores of Oedogonium, Cladophora, and Vaucheria he found
that the nucleus approaches the plasma membrane, which at that
point becomes thickened, forming a lens-shaped Mundstelle.
From this grow out the cilia, and at the base of each a small refract-
ive granule is present. A full discussion of the morphological
nature of these cilia-bearing structures and an extensive comparison
with those of higher plants were given in connection with a later
work (80). The main point to be noted at this time is that STRAS-
BURGER believed that the blepharoplasts of higher plants have been
derived from such swollen Hautschicht organs in the algae, and that
all of them are morphologically distinct from centrosomes.
DANGEARD (1'7) found a deeply staining granule at the base of
the cilia in Chlorogonium, but did not consider it a centrosome. In
: 89
go BOTANICAL GAZETTE [AUGUST
a later paper (18) he states that in Polytoma the cilia are inserted on
a similar granule which is believed to be a swelling of the ectoplasm.
In some cases he saw a delicate filament connecting this with another
minute body at the surface of the nucleus.
In Hydrodictyon (TIMBERLAKE 85) the cilia are inserted on a
small body lying in contact with the plasma membrane, but inde-
pendent of the latter. Protoplasmic strands join this structure
with the nucleus. At the poles of the spindle during the differentia-
tion of the spore Anlage, and later near the nucleus, two heavily
staining granules were seen, but their origin and further history
were not worked out.
In the zoospore origin of Derbesia, according to Davis (21), the
nucleus migrates toward the cell membrane and from it many
granules, which are not centrosomes, move out along radiating
strands of cytoplasm to the surface of the cell, where by fusion they
form a ring-shaped structure from which the cilia develop.
The development of the spermatozoid in Chara has been
described by BEtajerr (2) and by Mortter (71). Here the
blepharoplast arises as a differentiation of the plasma membrane
and bears two cilia. No centrosomes or Plasmahdcker were
observed at the base of the cilia, although ScHoTTLANDER (75) had
previously reported centrosomes in the cells of the spermatogenous
ament. :
Griccs (34) describes in a recent paper a deeply staining body
at the insertion point of the cilia in the zoospore of the fungus
Rhodochytrium. This is connected by fine cytoplasmic fibers
with the nucleus. The author states that no centrosomes were
observed.
In the myxomycete Stemonitis JauHN (56) has made a highly
suggestive observation. During the last mitosis in the formation
of the swarmers the spindle poles are occupied by centrosomes.
During the anaphases the flagella of the two resulting swarmers are
seen growing out directly from these centrosomes.
Among the bryophytes the blepharoplasts in Marchantia and
Fegatella have received the most attention. According to IKENO
(53) a centrosome comes out of the nucleus at each spermatogenous
division in Marchantia and divides to two, which diverge to opposite
*
1912] SHARP—SPERMATOGENESIS IN EQUISETUM gI
sides of the cell, occupy the spindle poles, and disappear at the close
of mitosis. It is possible that they are included within the mem-
branes of the daughter nuclei. After the last (diagonal) division,
however, they remain in the cytoplasm as the blepharoplasts,
elongating and bearing two cilia. IKENo regards these bodies as
‘true centrosomes. He further believes that the blepharoplasts of
peeophy tes and gymnosperms are derived ontogenetically or
phy] tically from centrosomes, but that all bodies called centro-
somes in nlanis may not be homologous. In a paper appearing
two years later, MIvAKe (66) states that although an inconstant
aster, often with a dot at the focus, may appear in the spermatoge-
nous divisions, no body like IkENo’s centrosome is present, except
at the last mitosis, when a body lies at each spindle pole as figured
by that author. Essentially the same results were obtained in
Fegatella, Pellia, Aneura, and Makinoa. Mryake believes that the
centrosome hitherto reported in the cells of the Hepaticae is nothing
but a center of cytoplasmic radiation, and inclines toward the view
of STRASBURGER that the blepharoplast and the centrosome are not
homologous structures. Escovez (22) states that in Marchantia
and Fegatella two “corpuscles” appear in the spermatid mother
cell in contact with the plasma membrane. These occupy the
spindle poles and in the spermatids function as blepharoplasts.
Escovez regards these organs as distinct from centrosomes, though
their origin was not traced. Centrosomes are reported by SCHAFF -
NER (74) in all the spermatogenous divisions in Marchantia. After
the last mitosis these behave as blepharoplasts, which are conse-
quently looked upon as modified centrosomes. BOLLETER (8)
found in Fegatella a centrosome-like body near the spindle pole at
the last division and observed its nuclear origin. He believes that.
it is present in the earlier division also.
In the antheridium of Riccia Lewis (61) reports centrosome-like
Structures in the early and diagonal divisions. These apparently
arise de novo in the cytoplasm at each mitosis, showing no continuity
through the succeeding cell generations except at the last mitosis,
when they persist and become the blepharoplasts. Lewis does
not think these bodies represent centrosomes.
The most recent investigations of the blepharoplast in bryo-
oOo
g2 BOTANICAL GAZETTE [AUGUST
phytes are embodied in two papers appearing in 1911. In the
first of these WoopBURN (95) gives an account of spermatogenesis
in Porella, Asterella, Marchantia, and Fegatella. He finds that the
blepharoplast is first distinguishable as a spherical granule in the
cytoplasm of the spermatid, and holds that it represents, as Mor-
TIER (71) had formerly suggested, an individualized part of the
kinoplasm arising de novo in certain spermatogenous cells. WILSON
(93) describes the phenomena occurring in Pellia, Atrichum, and
Mnium. In Mnium and Atrichum the spermatogenous divisions
show no centrosomes, while in Pellia centrospheres, and probably
centrosomes, are present during the later mitoses. The origin of
the blepharoplast as here described is very peculiar. In the sper-
matid of Mnium a number of bodies separate from the nucleolus
and pass out into the cytoplasm where they coalesce to form a
“limosphere.” The nucleolus then divides into two masses, both
of which pass into the cytoplasm; one functions as the blepharoplast
while the other gives rise to an accessory body. In Aérichum the
first body separated from the nucleolus becomes the blepharoplast,
a second forms the limosphere, and a third the accessory body. 4
Pellia the origin of these structures was not determined. In all
three plants the blepharoplast goes to the periphery of the cell and
produces a threadlike structure along the plasma membrane. The
nucleus then moves against this thread and the two metamorphose
together to form the spermatozoid. WuLson regards the blepharo-
plast as ‘‘ probably derived from a centrosome.”
According to Humpurey (49) the blepharoplast of Fossombromia
is first seen in the cytoplasm of the spermatid.
The early papers dealing with the spermatozoid in pteridophytes,
such as those of BUCHTIEN (9), CAMPBELL (12), BELAJEFF (1),
GUIGNARD (35), and ScHOTTLANDER (75), give us little or no
information concerning the development of the blepharoplast.
Our more definite knowledge of this subject dates from 1897, when
BELAJEFF published three short papers. In the first of these (3) it
is stated that the fern spermatozoid consists of a thread-shaped
nucleus and a plasma band, with a great many cilia growing out
from the latter. In the plasma band is inclosed a thin thread
which arises by the lengthening of a small body seen in the sperma-
1912] SHARP—SPERMATOGENESIS IN EQUISETUM 93
togenous cell. In the second paper (4) the blepharoplast of
Equisetum is first described as a crescent-shaped body lying against
the nucleus of the spermatid. This body stretches out to form the
cilia-bearing thread. The third contribution (5) is a short account
of the metamorphosis of the spermatid in Chara, ferns, and Equi-
setum. In all of these forms a small body elongates to form a
thread upon which small Hécker arise and grow out into cilia.
In a comparison with animal spermatogenesis, BELAJEFF here
homologizes the Koérperchen (blepharoplast) in the spermatid,
the thread to which it elongates, and the cilia of the plant, with the
centrosome, middle piece, and tail (perhaps only the axial filament),
respectively, of the animal. The following year, in connection
with a further discussion, he figured the details as made out by him
in Gymnogramme and Equisetum (6). In Gymnogramme the
blepharoplasts appear at opposite sides of the nucleus in the
spermatid mother cell, while in Equisetum a single blepharoplast is
first figured lying close to the nucleus of the spermatid, behaving
as outlined in the earlier accounts.
One of the most interesting cases is that of Marsilia, first
described by SHaw (76). According to this investigator a small
granule or “blepharoplastoid”’ appears near each daughter nucleus
of the mitosis which differentiates the grandmother cell of the
spermatid. During the next division these divide but soon dis-
appear, and a blepharoplast appears near each spindle pole. In
the next cell generation (spermatid mother cell) the blepharoplast
divides to two which become situated at the spindle poles in the
final mitosis. In the spermatid the blepharoplast shows a small
internal granule; this multiplies to several and forms a band which
elongates spirally with the nucleus and bears the cilia. SHAW sees
in these facts no ground for the homology of the blepharoplast and
the centrosome. BELAJEFF’s paper dealing with Marsilia appeared
in the following year (7). He found that centrosomes occur at the
poles during all, excepting possibly the first, of the series of divisions
which result finally in the 16 spermatids. After each mitosis the
centrosome divides to two which occupy the poles during the
next mitosis, and in the spermatid it performs the function of a
blepharoplast. BrLayerr regards this as a strong confirmation
94 BOTANICAL GAZETTE [AUGUST
of his theory that the blepharoplast and the centrosome are
homologous structures.
In Adiantum and Aspidium (THom 84) the blepharoplast is
described as a round body in the cytoplasm of the spermatid. It
is stated that it does not act as a centrosome during division, though
no figures of these stages are shown.
The most recent work dealing with the blepharoplast in pteri-
dophytes is that of YAMANOUCHI (97) on Nephrodium. In this
form there are no centrosomes in the whole life history. The two
blepharoplasts, which arise de novo in the cytoplasm of the spermatid
mother cell, take no active part in nuclear division, merely lying
near the poles of the spindle. In the spermatid the blepharoplast
elongates in close union with the nucleus to form the cilia-bearing
band.
The first known blepharoplast in plants above the algae was
discovered in Ginkgo by Hiraské (45) in 1894. He observed two,
one on either side of the body cell nucleus, and because of their
great similarity to certain structures in animal cells believed them
to be attraction spheres. It was not until two years later that this
investigator announced the discovery of the swimming sperm of
Ginkgo. In 1897 WEBBER (89) observed the same structures,
noting their cytoplasmic origin. On account of several differences
existing between these bodies and known centrosomes he expressed
the belief that they are not true centrosomes, but distinct organs
of spermatic cells, and first applied to them the name blepharo-
plast. Fuym (30, 31, 32) gave several figures of spermatogenesis
in Ginkgo, which agree with the accounts of Hrrasé and
WessBer. The same subject has been dealt with more recently
by Miyake (67).
In two short papers appearing in sag7, WEBBER described the
blepharoplast of Zamia (87, 88), and in 1901 a very full account
was published (90). According to this author two blepharoplasts
arise de novo in the cytoplasm. They are surrounded by radiations
up to the time of the division of the body cell, but these have no
part in the formation of the spindle, which is entirely intranuclear.
During mitosis the blepharoplasts, lying opposite the poles, become
vacuolate and break up to many granules which unite to form the
1912] SHARP—SPERMATOGENESIS IN EQUISETUM 95
cilia-bearing band. In this paper WEBBER gives a very extensive
discussion of the morphological nature of the blepharoplast which
will be referred to later.
IKENO (51) expressed the opinion that the blepharoplast of
Ginkgo and the cycads is not only similar to a centrosome but is a
true centrosome, a view shared by GuIGNARD (36). Soon after
this IkeNo’s full account of gametogenesis and fertilization in
Cycas appeared (52). In this paper it was shown that the blepharo-
plasts appear in the body cell, lie opposite the spindle poles during
mitosis, and break up to granules which fuse to form the spiral band
in a manner similar to that described by WEBBER for Zamia.
Several years later the same writer published two papers
-dealing with the morphological nature of the blepharoplast. In
the first of these (54) he reviews the former work on the subject and
makes comparisons with analogous phenomena in animals, which
he believes sustain the homologies of BELayerr. He points out
that in Marchantia centrosomes are present in all the spermatoge-
nous divisions, while in other liverworts they appear much later,
and from this argues that the bryophytes show various stages in the
elimination of the centrosome. He strongly reasserts his. belief
that blepharoplasts are centrosomes and speaks of the “ Umwand-
lung eines Zentrosoms zu einem Blepharoplast” in the development
of a spermatid into a spermatozoid. The Hautschicht organs of the
algae are also held to be ontogenetically or phylogenetically derived
from centrosomes. In the later contribution (55) he insists less
strongly upon the morphological identity of all blepharoplasts,
separating them into three categories: (1) centrosomatic blepharo-
plasts, including those of the myxomycetes, bryophytes, pterido-
phytes, and gymnosperms; (2) plasmodermal blepharoplasts, those
of Chara and some Chlorophyceae; (3) nuclear blepharoplasts,
found only in a few flagellates.
The blepharoplasts of Microcycas (CALDWELL 11) appear in the
cytoplasm of the body cell, often very close to each other. They
are surrounded by prominent radiations and lie opposite the spindle
poles through mitosis. At metaphase they have already broken
up and begun the formation of the spiral band.
CHAMBERLAIN (15) observed in the cytoplasm of the body cell
96 BOTANICAL GAZETTE [AUGUST
of Dioon a number of very minute “black granules” which he was
inclined to believe originate within the nucleus. Very soon two
undoubted blepharoplasts are present, and are apparently formed
by the enlargement of two of the original black granules. Very
conspicuous radiations develop about them, and after mitosis they
form the cilia-bearing band as in other cycads. In an earlier
paper (13) on the homology of the blepharoplast CHAMBERLAIN
expressed the opinion that it is to be regarded as a centrosome.
From the foregoing historical review it is evident that there are
two general views concerning the morphological nature of the
blepharoplast as seen in bryophytes, pteridophytes, and gymno-
sperms:
(1) The blepharoplast represents a centrosome (Hiras£, IKENO,
BELAJEFF, GUIGNARD, SCHAFFNER, WILSON, CHAMBERLAIN).
(2) The blepharoplast is specialized kinoplasmic or cytoplasmic
material but not a centrosome (STRASBURGER, WEBBER, SHAW,
Lewis, THom, EscovEz, WooDBURN).
The present study of spermatogenesis in Equisetum was under-
taken in the hope of shedding further light upon the relative merits
of these two views, and it is with particular reference to this prob-
lem that the results are given consideration in the following pages.
Materials and methods
Spores were collected in Chicago, May 15, 1911, and sown upon
clean sand watered from below. These cultures were kept under
ground glass in the greenhouse of the Hull Botanical Laboratory.
In five weeks, a somewhat longer time than is usually necessary,
sperms were swimming in large numbers.
Several killing fluids and stains were used. By far the most
satisfactory results were obtained with the iron-hematoxylin of
Haidenhain after a killing fluid made up as follows: bichromate of
potash 2.5 gm., bichloride of mercury 5 gm., water 9o cc., freshly
distilled neutral formalin to cc.
Description
The usual statement concerning the antheridium of Equisetum is
that it occurs in two forms, developing in some cases like the anthe-
ridium of the eusporangiate pteridophytes, and in others from a
1912] SHARP—SPERMATOGENESIS IN EQUISETUM 07
papillate cell as in the Filicales. The mode of development has
usually been correlated with the position of the antheridium
initial in the prothallium. An adequate study of antheridium
development was not made in connection with the present work on
Equisetum arvense, but of the many young antheridia examined
not one was unmistakably of the latter form. Apparently any
of the cells of the prothallium, especially those near the apex, are
able to divide periclinally and produce antheridia of the well known
imbedded type.
In the nuclei of the spermatogenous cells the chromatin has the
form of a ragged network of rather close mesh, the greater part of
it being accumulated in knots at the intersections. One or more
conspicuous nucleoli are present. The cytoplasm during the earlier
cell generations may contain many plastids in various stages of
is tion; in most cases these are no longer evident by the
time the 8 or 16-celled stage has been reached, but occasionally they
persist and are found in considerable numbers in the penultimate
cell generation, or even in the spermatids. It is obviously neces-
sary to select for critical study of the details of blepharoplast
development those antheridia in which the plastids do not introduce
an element of uncertainty.
The main point to be noted in connection with mitosis in the
early cell generations is that there are present no bodies which
could possibly be interpreted as centrosomes. The spindle fibers
are very weakly developed and end at the poles without any signs
of centrosomes, centrospheres, or asters.
The first conspicuous indication of approaching sperm formation
is seen in the rounding off of the cells of the penultimate generation
(fig. 1). They begin to separate at the corners and gradually draw
away from each other until they are entirely free. Although the
division of these cells results in the production of sperms n pairs,
it becomes inaccurate to speak here of mother cells with two sperms
developing in each, since the intervening walls may persist until
the aie are mature or may break down at once. By designating
them “penultimate cells” this ambiguity is avoided. Their
number at the time of rounding off varies greatly in different
antheridia. The observed range was 64 to 512, which means that
98 BOTANICAL GAZETTE [AUGUST
the number of sperms per antheridium varies from 128 to 1024
(approximately). Correlated with this is a great difference in the
size of the antheridia. The sperms themselves also show consider-
able variation in dimension, as a comparison of figs. 28 and 29 will
show. The nucleus of the penultimate cell at the time of separa-
- tion is in the resting condition. The cytoplasm has a very fine
and uniform structure, and in most cases is entirely free from
plastids or other inclusions. Vacuoles are present only very
rarely.
While the penultimate cells are rounding off from one another
there appears in the cytoplasm near the nucleus a very minute
granule which stains intensely with iron-hematoxylin (fig. 2). Its
diameter lies between 0.25 and 0.3. Very faint cytoplasmic
radiations extend out from it in all directions, forming a very weakly
developed aster. In other cells of the same antheridium the granule
is seen to be dumb-bell shaped, and in still other cells distinctly
double, showing that it divides to two (figs. 3, 4). These paired
bodies are the blepharoplasts. Immediately after division their
diameter increases to 0.5. Their radiations become more pro-
nounced and the nucleus often becomes flattened or slightly
indented at the point where they lie, as in fig. 8.
The origin of the single granule cannot be stated with certainty.
When first made out it holds a position near the nuclear membrane,
a fact which would suggest its nuclear origin, but no other evidence
in favor of this interpretation was obtained. The nuclear mem-
brane shows no indication of recent disturbance. Moreover, it is
highly improbable that such a granule could be distinguished within
the nucleus because of its small size, its similarity in staining reac-
tion to the chromatin network, and the density of the latter. Some
light may be shed upon the question by exceptional cells like that
shown in fig. 5. Here are scattered through the cytoplasm many
very small intensely staining bodies, a few of which occur in pairs.
When first seen these granules lie in all positions with respect to the
nucleus and the plasma membrane. Some of the paired granules
are distinctly larger than the single ones; the pair nearest the nu-
clear membrane is always the largest, has the most evident radi-
ations, and is without doubt the same structure shown in fig. 4-
1912] SHARP—SPERMATOGENESIS IN EQUISETUM 99
In other cells of the same antheridium only this pair is present,
the other bodies, if formerly present, having been resorbed.
One can hardly speak conclusively regarding all points in the
history of such minute structures. The evidence at hand, however,
inclines the present writer toward the belief that the original single
granule, which by division gives rise to the two blepharoplasts, is
in some cases one of a number which may appear de novo in the
cytoplasm and start development.
The two blepharoplasts, which lie very close together for a little
time immediately following their formation from a single body, soon
begin to move apart. As they do so a very distinct central spindle
develops between them, so that a faint but undoubted amphiaster
is formed (figs. 6, 7). In some preparations the rays on the side
toward the nucleus are somewhat heavier than the others and form
a distinct cone (fig. 6). This feature is not made out in all cases.
A line joining the two blepharoplasts may lie in any position with
respect to the nuclear membrane, though the situation shown in
fig. 6 is the most usual one. The blepharoplasts continue to
separate, moving in paths close to the nuclear membrane, until
they lie 180° apart (figs. 8-12). During the earlier stages of the
migration the central spindle gradually fades out (fig. 8). The
astral radiations persist, and when the blepharoplasts reach polar
positions those on the side toward the nucleus become more distinct,
being especially conspicuous when the blepharoplasts move a little
distance away from the nucleus (fig. 13). They form two cones
with the blepharoplasts at their apices, while the radiations extend-
ing in other directions remain very faint. The rays of the cone
do not diverge from a single point on the blepharoplast, but pass
out from a large portion of its surface. At this stage the blepharo-
plast may reach a diameter of o. 75 #.
In the nucleus are now seen indications of the approaching
mitosis which is to differentiate the spermatids. The nuclear
reticulum gradually becomes coarser and eventually resolves itself
into a spirem (fig. 14). While the spirem is segmenting to form the
chromosomes the nuclear membrane breaks down and the fibers
radiating from the blepharoplasts extend into the nuclear cavity
and establish the karyokinetic figure. The spindle is extremely |
I0O BOTANICAL GAZETTE [AUGUST
weak in development, so that the relation it bears to the blepharo-
plasts is not always easily determined at this time. There is no
question, however, that the blepharoplasts continue to occupy the
poles (fig. 15), as would be expected after the situation in the imme-
diately preceding stages. In the later stages of division many
extremely fine strands are present between the daughter nuclei.
Whether these are the remains of fibers passing from one blepharo-
plast to the other or represent the visible effect of the separation of
the chromatin upon the cytoplasm was not determined. The cell
plate separating the paired spermatids is very late in forming.
During the anaphases of karyokinesis a peculiar change occurs
in the blepharoplasts. For a time they lose their affinity for iron-
hematoxylin, so that in many preparations treated in the usual way
with this stain they may be wholly indiscernable. In more deeply
stained cells they appear as translucent bodies considerably larger
than during the earlier phases of division (fig. 16). They are no
longer solid but contain one or two large vacuoles, which give them
in section the appearance of small rings. It is probable that the
decrease in staining capacity is due to swelling through the absorp-
tion of water without any increase in stainable material. This
condition exists only through the remainder of the division; when
the sister spermatids are well rounded away from each other the
blepharoplasts as a general rule stain deeply again. The vacuole
or vacuoles form an irregular cavity, and the whole structure soon
takes the form of an uneven ring (figs. 17, 18).
The blepharoplast now breaks up to several pieces which become
arranged in a row, usually at once (fig. 19). These pieces multiply
rapidly by further fragmentation and form a beaded chain extending
about halfway around the nucleus (fig. 21). Fig. 20 shows a mass
of these granules just beginning to draw out into a row.
It is at this beaded stage that the cilia begin to develop. From
the blepharoplast granules there are seen very fine strands extend-
ing toward the periphery of the cell (fig. 21). Whether more than
one of the strands, or rudimentary cilia, ever grow out from a single
granule was not definitely determined, but since the cilia of the
mature spermatozoid and the granules are approximately equiva-
lent in number, it is probable that as a rule each granule gives rise
1912] SHARP—SPERMATOGENESIS IN EQUISETUM IOI
to one cilium. The further details of cilium development were not
worked out. ;
The blepharoplast granules, wh'ch have been lying close together
or in contact, now fuse to form a continuous thread. The coales-
cence usually begins at one end of the chain so that at certain
stages it appears solid at one extremity and broken at the other
(fig. 22). The union, although intimate, is not so complete that
the thread is uniform in diameter throughout, even in the later
stages. When the metamorphosis of the spermatid is half complete
the beaded nature of the blepharoplast is clearly evident, and when
the spermatozoids are mature it still shows an uneven outline.
Immediate y after the union of the granules the nucleus begins
to show marked changes. It moves to one side of the cell and
begins to draw out into a flattened point next to the blepharoplast
(fig. 23). At this stage the nucleus and the blepharoplast lie rather
close together; the relative position of the two is seen in fig. 24,
which represents a portion of a similar cell viewed from the direc-
tion a. The nucleus continues to elongate and quickly assumes a
crescentic form, while its reticulum becomes very coarse and deeply
staining (fig. 25). The blepharoplast also lengthens spirally, and
the two become widely separated from one another. Figs. 26 and
27 represent respectively an entire cell like that of fig. 25 viewed
from the direction @, and a section in the plane ab. No connections
other than the undifferentiated cytoplasm are present between the
nucleus and the blepharoplast. The cilia have now increased
markedly in length.
As previously noted, the mature spermatozoids vary greatly in
size in different antheridia, which may be seen by ‘comparing
figs. 28 and 29. The nucleus now stains intensely with iron-
hematoxylin. Its surface presents a mottled appearance, while
very lightiy stained sections show that its interior is quite homo-
geneous, with several very small vacuoles along the central region.
Scattered over the nucleus, mostly along its concave face and occa-
sionally elsewhere in the cytoplasm, are many black globules whose
origin and nature were not determined. A few vacuoles are present
in the cytoplasm. The blepharoplast continues its spiral growth
until it has made about 1.4 turns. The nucleus makes 0.7 of a
102 BOTANICAL GAZETTE [AUGUST
turn, but lies parallel to the blepharoplast for 0.44 of a turn, so
that the entire spermatozoid makes 1.66 turns. In all of the
spermatozoids examined the direction of coiling is the same—from
right to left beginning at the innermost end of the blepharoplast
when the side of the cell containing the latter is turned toward the
observer. :
After escape from the antheridium the larger or posterior portion
of the nucleus becomes extended and somewhat flattened. Both
nucleus and cytoplasm absorb water and show decided enlarge-
ment, the cytoplasm, especially in the posterior portion of the
spermatozoid, becoming very coarse and foamy through the great
enlargement of the vacuoles. Such a mature spermatozoid fixed
in the swimming condition over osmic fumes is represented in fig.
30. Exclusive of the cilia it has a length of 19.7 ».
Discussion
The morphological nature of the blepharoplast is a topic which
has been so extensively discussed by STRASBURGER, WEBBER, IKENO,
and others that the present writer does not take up the subject with
reference to the additional evidence afforded by Equisetum without
risk, or even necessity, of a certain amount of repetition. In the
foregoing historical résumé it was seen that the central point of the
discussion has been the question of the possible morphological
identity of the centrosome and the blepharoplast. Any analysis
of the relationship existing between these two structures must
include a consideration of the centrosome as found elsewhere in the
plant kingdom, and since it has to do with a cell problem of general
interest it should proceed in the light of certain phenomena occur-
ring in the spermatogenesis in animals.
One of the earliest known centrosomes in plants was that dis-
covered by Bi'rscutt (10) in the diatom Surirella. It had earlier
been seen by SmirH (77), who, however, did not recognize its true
nature and termed it the “germinal dot.’”’ A full account of this
centrosome was given by LAUTERBORN (59) in his magnificent work
on the diatoms, and later by Karsten (57). It lies near the nu-
cleus, becomes surrounded by radiations, divides and forms the
central spindle of the karyokinetic figure in a very peculiar manner.
1912] SHARP—SPERMATOGENESIS IN EQUISETUM 103
During karyokinesis it lies near the pole of the broad-poled
spindle.
Centrosomes in the Sphacelariaceae have been described by
STRASBURGER (78), Humpurey (48), and SwIncLe (83). In the
vegetative cells of Sphacelaria the centrosome, according to STRAS-
BURGER, is situated in a centrosphere at the center of an aster.
Previous to mitosis it divides to two which take up positions at
opposite poles. In Stypocaulon SwiNGLE has shown that the
centrosome, which lies close to the nucleus, divides, the daughter
centrosomes diverging to opposite sides of the nucleus and occupy-
ing the spindle poles throughout mitosis. At all stages asters are
present. SWINGLE is inclined to regard this centrosome as a
permanent organ of the cell.
In the oogonium and segmenting oospore of Fucus FARMER
and WILLIAMS (24, 25) described two centrospheres arising inde-
pendently 180° apart. In the centrosphere they often observed
several granules, but were inclined to attach no importance to
them. StTRASBURGER (79) reported definite centrosomes with
asters all through karyokinesis; in the sporeling are stages which
indicate that it is a dividing body. He regarded it as a permanent
cell organ. In a more recent investigation YAMANOUCHI (98)
demonstrates in the antheridium and oogonium two very definite
centrosomes, which appear independently of each other, become
surrounded by conspicuous asters, and occupy the spindle poles
during karyokinesis. He further shows that when the sperm
reaches the egg nucleus a new centrosome appears on the nuclear
membrane at the spot where the sperm entered.
The centrosome of Dictyota has been dealt with by two investi-
gators. Mortrer (69, 70) states that in the two divisions in the
tetraspore mother cell, in at least the first three or four cell genera-
tions of the sporeling and in all the vegetative cells of the tetrasporic
plant, a curved rod-shaped centrosome with an aster occurs at the
spindle pole. During the early phases of karyokinesis it divides,
the daughter centrosomes passing to opposite poles. WILLIAMS
(91) figures centrosomes and asters essentially like those described
by Mortier. He also states that the entrance of the sperm causes
a centrosome with radiations to appear in the egg cytoplasm.
104 BOTANICAL GAZETTE [AUGUST
Wo tFe (94) found in his study of Nemalion that the spindle
poles are always occupied, except possibly in the antheridial mi-
toses, by two heavily staining bodies which he considers centro-
somes. They are surrounded by hyaline areas and apparently
divide, but no radiations are present.
In Polysiphonia (YAMANOUCHI 96) there are during the pro-
phases of every mitosis two centrosome-like bodies in the kinoplasm
at opposite poles of the nucleus. A little later the small bodies
disappear, while the kinoplasm takes the form of large centrosphere-
like structures without radiations. During the late anaphases these
become indistinguishable. YAMANOUCHI believes that these struc-
tures are not permanent cell organs, but are formed de novo at the
beginning of each mitosis.
In the tetraspore mother cell of Corallina (DAvis 19, YAMA-
NOUCHI 99) two deeply staining masses, or centrospheres, occur at
opposite ends of the nucleus during the prophases of karyokinesis.
They occupy the spindle poles and are surrounded by radiations.
During the later anaphases they disappear and are formed de novo
at the next division. No true centrosomes are present.
Among the fungi the best known centrosomes are those of the
Ascomycetes. HARPER (40, 41, 42, 43) has described in the asci of
Peziza, Ascobolus, Erysiphe, Lachnea, Phyllactinia, and other genera
granular disc-shaped centrospheres surrounded by asters at the
poles of the spindle. He regards them as permanent organs of the
cell. GUILLIERMOND (37, 38) shows the presence of centrosomes
and asters in several other genera. Especially interesting is the
account of Gallactinia succosa given by Matre (62) and later by
GUILLIERMOND (39). In the ascus of this form a single centrosome
arises within the nucleus with a cone of fibers extending toward the
chromatin. It divides to two which take up positions 180° apart
at the nuclear membrane, at which time asters develop in the cyto-
plasm. Fav (26) found that in Hydnobolites a large centrosome
appears outside the nucleus during the prophases of karyokinesis.
In Neotiella the spindle terminates in minute centrosomes with
astral rays very faint or absent. In Sordaria he describes the
centrosomes as disc-shaped while the cell is in the resting condition
and round and smaller during division. The formation of the
-
1gI2] SHARP—SPERMATOGENESIS IN EQUISETUM TO5
spindle was not made out in these three forms. According to SANDS
(73) the discoid “central body” or centrosome of Microsphaera
divides with its aster to two which occupy the poles during karyo-
kinesis. In Humaria rutilans Miss FRASER (27) saw at first two
centrosomes lying near each other, each at the apex of a cone of
fibers and surrounded by a very faint aster. These move apart
and establish the spindle in the usual way. Centrosomes are also
figured in Ascobolus and Lachnea (FRASER and Brooxs 29). In
Otidea and Peziza vesiculosa (FRASER and WELSFORD 28) there are
distinct centrosomes and asters. The figures given in this paper
indicate that division of the centrosome occurs in the latter species.
In a recent contribution CLAUSSEN (16) figures centrosomes with
weakly developed asters in Pyronema. The origin of the spindle
is not shown.
The first centrosome described in the liverworts was that of
Marchantia by ScHoTTLANDER in 1893 (75). According to this
observer the centrosome in the spermatogenous cells divides
during the anaphases of. mitosis, so that each daughter nucleus
is accompanied by two. In the gametophytic cells certain minute
bodies with radiations at the poles of the elongated nucleus and
of the spindle are believed by Van Hoox (86) to represent
centrosomes.
Pellia has been the subject of four investigations dealing with
the centrosome. In 1894 FARMER and REEVES (23) gave an
account of mitosis in the germinating spore. They reported two
centrospheres at opposite sides of the nucleus with conspicuous
radiations but no true centrosomes. The centrospheres occupy
the spindle poles and disappear during the telophases of division.
Davis (20) studied the same mitoses and obtained similar results.
He states, however, that the centrospheres fade out somewhat
earlier. The account given by CHAMBERLAIN (14) agrees with
these in the essential features. The structures are very distinct
in the first mitosis but become less so in the succeeding ones. The
most recent work is that of GREGOIRE and Bercus (33). By using
improved methods these investigators have found that neither in
the resting cells nor during mitosis are there centrospheres or central
corpuscles. The centrospheres described by other writers are
106 BOTANICAL GAZETTE [AUGUST
shown to be appearances due to the intersection of the very
numerous astral radiations at a common point or region. The
achromatic figure is derived entirely by the rearrangement of the
cytoplasmic network.
As the centrosome becomes more widely pasties it becomes
increasingly difficult to formulate for it any adequate definition.
There is scarcely a single attribute common to all true centrosomes;
nevertheless there are in general certain features which are fairly
characteristic of them as they appear in plants and animals, most
prominent among which are the position at the spindle poles with
all that this implies, the possession of an aster, and the division to
form daughter centrosomes. Because of many exceptions no one
of these by itself will definitely determine the morphological nature
of a structure possessing it, but when all of them are present we can
no longer doubt that we are dealing with a true centrosome.
In a survey of the cilia-bearing structures of bryophytes, pterido-
phytes, and gymnosperms it is seen that in general the centrosome-
like characteristics of the blepharoplast become less and less evident
in passing upward through these groups, while the phenomena
connected with the bearing of cilia become increasingly prominent.
‘In the bryophytes the conflicting accounts leave us in some doubt
concerning the early history of the blepharoplast, but in some cases -
at least it appears that centrosomes exist through several cell
generations and after the last mitosis function as blepharoplasts.
In those forms which show them only during the last division they
occupy the spindle poles and behave as typical centrosomes. In
the spermatids each simply elongates and bears two cilia. In the
Filicales, as shown by YAMANoUcHI’s work on Nephrodium, the
blepharoplast is limited to the last mitosis and does not exhibit the
characters of a centrosome, having no division, no radiations, and
only occasionally occupying the pole of the spindle. It elongates
in intimate union with the spermatid nucleus and bears many cilia.
In the gymnosperms the blepharoplast, although surrounded by
prominent radiations, appears to play little or no active part in
mitosis. In its subsequent behavior it differs widely from the
blepharoplasts of the bryophytes and Filicales. After enlarging
it becomes vacuolate and breaks up into many fragments, which
1912] SHARP—SPERMATOGENESIS IN EQUISETUM 107
arrange themselves in a row and coalesce to form the cilia-bearing
band.
The peculiar interest of the phenomena in Eguisetum is here
evident. Although limited to a single mitosis in the antheridium,
the blepharoplast retains in its activities the most unmistakable
evidences of a centrosome nature, and at the same time shows a
metamorphosis strikingly like that in the cycads. In thus combin-
ing the main characteristics of true centrosomes with the peculiar
features of the most advanced blepharoplasts, it reveals in its
ontogeny an outline of the phylogeny of the blepharoplast as it is
seen developing through bryophytes, pteridophytes, and gymno-
sperms, from a functional centrosome to a highly differentiated
cilia-bearing organ with very few centrosome resemblances. In
Marsilia the same pronounced centrosome behavior is shown
through at least three cell generations, and in the formation of the
cilia-bearing band the cycad situation is foreshadowed, though not
to the marked degree seen in Equisetum. To the present writer
these facts seem to constitute conclusive evidence in favor of the
theory advanced by BELAJEFF and by IKENo, that the centrosome
has gradually assumed the function of bearing cilia, at the same time —
losing the usual properties of a centrosome.
The points brought out in such a review are especially suggestive
in connection with the conclusions to which WEBBER has been
drawn by his studies on Zamia (90). This investigator empha-
sizes very strongly the view that the blepharoplast is a distinct
organ functioning only as a cilia-former, and urges several objec-
tions to its centrosome nature. He points out that it differs from
known true centrosomes in not being at the center of an aster at
the poles and having no connection with spindle formation, in
being limited to a single cell generation, in its great size, in its
fragmentation, in its growth into a band, in its function of bearing
cilia as far as plant centrosomes aré concerned, and in its behavior
in fertilization. Although the blepharoplasts of other plant groups
are discussed, it appears that these conclusions must have been
formulated largely through a consideration of the cycad situation.
When the blepharoplast is regarded as an organ developing pro-
Sressively through bryophytes, pteridophytes, and gymnosperms,
108 BOTANICAL GAZETTE [AUGUST
and is treated in the light of analogous phenomena in animals, much
of the apparent force of these objections is removed.
In Marsilia, as BELAJEFF indicates in his fig. 7 (7), and in
Equisetum, the blepharoplasts are surrounded during the early
- stages by asters, though these are very weakly developed. When
they separate there appears a central spindle, forming with the
asters an amphiaster so characteristic of animal cells. In Equisetum
the radiations persist during the divergence of the blepharoplasts to
opposite sides of the cell, and those on the side toward the nucleus
remain as the achromatic portion of the karyokinetic figure. The
weakness of the other rays or their failure to remain seems to be a
matter of secondary importance in the light of spindle-forming
activity of this sort. Furthermore, the figures given by zoologists
indicate that the occurrence of an aster about the centrosome at the
spindle pole is by no means universal in animal cells. In discussing
this phase of the question IkeNo (54) cites the work of MEvEs and
KorrF (65) upon the myriopod Lithobius forficatus, in which the
spermatocyte centrosomes lie at a considerable distance from the
spindle poles during mitosis. The figures given by MEvEsS and
Korrr are strikingly like those of Ginkgo (Hiraské) and Cycas
(IkENO).
It is true that the blepharoplast is, as a rule, limited to a single
mitosis, but here we must remember the case of Marsilia where it is
present during three, possibly all four, of the spermatogenous divi-
sions, and also certain liverworts in which a similar condition has
been reported. WEBBER accounts for the occurrence of blepharo-
plasts in all the spermatogenous cell generations in Marsilia by
considering the latter potential spermatozoids, and thus regards
the fact that they appear de novo in each cell generation only to
disappear at the close of division as a support to his theory of the
independent nature of the blepharoplast. If the cells between the
central cell of the antheridium and the final spermatids are held to
be potential spermatozoids, we should expect, as WEBBER points
out, blepharoplasts or their rudiments to be present occasionally.
Although these ideas are in accord with the conception of the
blepharoplast as an organ sui generis, at the same time it does not
seem to the present writer that they offer any necessary argument
1912] SHARP—SPERMATOGENESIS IN EQUISETUM 109
against its centrosome nature, especially since such “rudiments”
as are seen in the spermatogenous cells of Marsilia and probably
certain liverworts are so remarkably centrosome-like. Moreover,
many true centrosomes appear de novo in each successive cell genera-
tion only to disappear at the close of mitosis.
If the centrosome be an organ which has been practically elimi-
nated from higher plants, we should not be surprised to see it
retained, if at all, in different degrees in different plants, and in those
cells in which it performs an important biological function, as
other workers have suggested. WerBBER’s statement that no known
plant centrosome has the function of bearing cilia is no longer
without a possible exception, since JAHN (56) has seen the flagellum
of the swarmer of Stemonitis growing out from the centrosome
during mitosis, exactly paralleling what HENNEGUY (44) observed
in an insect. That the bearing of cilia is the function which is
to be held accountable for the retention of the centrosome in
spermatogenous cells seems highly probable. After having lost
the usual functions of a centrosome we might well find it appearing
still later, in the spermatid itself, as WoopBURN (95) believes it
does in certain liverworts. BErLAJEFF’s view concerning the pres-
ence of these structures only in the eo cells is that
every cell has its definite ‘‘dynamic center,” but “only in these cases
isa staining substance present.
That growth into a band or thread does not deny the centrosome
nature of an organ is shown by the great bodily elongation of the
inner centrosome in the spermatozoon of Helix (Korrr 58) and
certain elasmobranchs (SuzuKI 82, Moore 68). The rodlike
centrosome of Dictyota and the discoid one of certain ascomycetes
constitute a further argument against allowing the character of
shape to enter into the definition of the centrosome.
Thus from the standpoint of the theory stated in the foregoing
pages, the occurrence of secondary peculiarities developed in con-
nection with cilia-bearing in the cycads and certain pteridophytes,
such as large size, fragmentation, and growth into a band, does
not dist nguish the blepharoplast from the centrosome. This is
emphasized by the fact that the first two of these features do not
occur in the blepharoplasts of bryophytes and most pteridophytes,
IIo BOTANICAL GAZETTE [AUGUST
but begin to appear in other members of the latter group, combined
with earlier stages in all essential points centrosome-like.
Both WEBBER and STRASBURGER have pointed out that the
blepharoplast, since it remains behind in the cytoplasm of the egg
and does not meet the female nucleus, is inactive in fertilization,
while in animals the centrosome brought into the egg by the
spermatozoon plays a very important réle in fertilization and in the
first cleavage mitosis. They advance this as a further evidence
that the blepharoplast and the centrosome are not homologous.
We have seen that as the blepharoplast has become more and more
highly differentiated in relation to the bearing of cilia, it has gradu-
ally lost the characters which would serve to mark it as a centro-
some. The disappearance of activity during fertilization along
with the other usual centrosome functions would be expected, if,
indeed, the sperm centrosome of plants ever did take any active
part in this process. In Nephrodium (YAMANOUCHI 97) and
probably many other pteridophytes and bryophytes the entire
spermatozoid enters the egg nucleus, but it is highly improbable
that the presence of the blepharoplast in these cases is necessary
to fertilization. On the other hand, we cannot yet certainly
conclude that a structure is entirely passive in fertilization merely
because it does not reach the female nucleus or produce other
striking visible effects. In any case it should be remembered that
function is not that upon which we can base homology.
In denying the identity of the blepharoplast and the centrosome
STRASBURGER (80) derives the blepharoplasts of bryophytes,
pteridophytes, and gymnosperms from the thickened Hautschicht
organs of algal swarm spores and gametes. This theory appears
to have the support of current conceptions of phylogeny, but it
leaves the remarkable behavior of the liverwort, Marsilia, and
Equisetum blepharoplasts to be accounted for. That the Haul-
schicht organ seen in algae should assume, during the course of
evolution, such centrosome-like characters, adding them at the
earlier end of its life history, seems more difficult of comprehension
than the theory stated in the foregoing pages—that the centrosome
has gradually taken on the cilia-bearing function.
Igt2] SHARP—SPERMATOGENESIS IN EQUISETUM TE}
Through his work on Marchantia IkENO was led to state a view
which might appear to lessen the contrast between the above two
theories. He pointed out (54) the resemblance between the elonga-
tion of the blepharoplast along the plasma membrane of the
Marchantia spermatid and the formation of the thickened portion
of the Hautschicht in the algae as described by STRASBURGER and
others, and concluded that this thickening has almost without doubt
been derived from a centrosome ontogenetically or phylogenetically,
that it is the metamorphosis product of a centrosome. His belief
that the basal body in the swarm spore of Hydrodictyon is to be
accounted for in a similar way was strengthened by the fact that
TIMBERLAKE (85) observed what were evidently centrosomes at
the poles of the spindles giving rise to the spore Anlage. In his
later paper (55) IKENo is less inclined to include the algal Haut-
schicht organs in the same morphological category with the blepharo-
plasts of the higher plants, but places them in a class apart—“‘plas-
modermal blepharoplasts.”
In the light of our limited knowledge of the history of the bleph-
aroplasts in algae it seems wisest to make this disposition of them
for the present. Otherwise we should be compelled to assume
their homology with those of the higher groups from which they
differ so widely in origin, appearance, and general behavior. Since
we can no longer remain in doubt concerning the centrosome nature
of the blepharoplast of higher plants, this assumption would mean
that the alga blepharoplast has lost all centrosome properties and
now arises in the motile cell itself in a very modified manner, making
it farther advanced in this respect than those of the higher groups,
which we can hardly regard as probable. Before any final judg-
ment can be rendered on this question more data must be gathered
from the algae themselves, from those forms which show both cen-
trosomes and blepharoplasts in their life histories.
The researches of Moore (68), MEvEs (63, 64), Korrr (58),
PAULMIER (72), and several others have established beyond ques-
tion the fact that the centrosome (or centrosomes) of the animal
spermatid plays an important réle in the formation of the motor
apparatus of the spermatozoon, the axial filament of the flagellum
II2 BOTANICAL GAZETTE [AUGUST
growing out directly from it. HrNNEGUY (44) even observed cilia
attached to the centrosomes of the karyokinetic figure in the sper-
matocyte of an insect.
In comparing the structures of the plant spermatozoid with those
of the animal spermatozoon, BELAJEFF (5) regarded the blepharo-
plast, the thread to which it elongates, and the cilia of the former
as homologous with the centrosome, middle piece, and tail, respec-
tively, of the latter. The blepharoplast of Chara is included in this
comparison in spite of the apparent difference in its mode of origin.
STRASBURGER (80), although agreeing that the body at the base
of the flagellum of the animal sperm is a centrosome, homologized
only the axial filament of the flagellum with the blepharoplast.
This comparison leaves both the cilia of the plant spermatozoid
and the centrosome of the animal spermatozoon without counter-
parts, though a complete homology of this sort is by no means a
necessity. The behavior of the centrosomes in the spermatid of
Helix (KorrF 58) has made it evident that the axial filament of
the flagellum is not a differentiation of the cytoplasm, starting at the
centrosome, but is made up of the centrosome substance itself.
Thus in comparing the blepharoplast to the axial filament its
centrosome relationship is not entirely avoided. In a discussion of
this question E. B. Witson (92) regards the work of SHaw and
BELAJEFF on Marsilia as establishing beyond question the identity
of the blepharoplast and the centrosome. He considers the
comparison of BELAJEFF as justified and concludes that “the facts
give the strongest ground for the conclusion that the formation of
the spermatozoids os in its essential features with that
of the spermatozoa. ....
The deeply staining bodies at the base of the flagella in other
ciliated animal cells have also been investigated for further light
upon this problem. That they correspond to centrosomes has been
rendered highly probable by the work of HENNEGUY (44) and
LENHOSSEK (60), while StupNicKA (81) has obtained evidence
apparently in favor of a contrary interpretation. This question
must remain with others for further researches to clear up.
In the meantime it should be borne in mind that whatever
interpretation is finally put upon the cilia-bearing structures of any
‘ 1912] SHARP—SPERMATOGENESIS IN EQUISETUM 113
plant or animal group, it must not be forced upon those of all other
groups. Since homologies are not determined by function, there
is no necessity for expecting all of these organs to belong to the same
‘morphological category. It is in the algae that the blepharoplast
of plants at present stands most in need of elucidation. In the
bryophytes, pteridophytes, and gymnosperms there can now remain
no question that the blepharoplasts are all homologous structures,
and that they are, to use IkENO’s expression, “ontogenetically or
phylogenetically centrosomes.”’
Summary
1. In the early mitoses in the spermatogenous tissue of Equi-
setum there are no centrosomes, centrospheres, or asters.
2. A minute granule, surrounded by a weakly developed aster,
appears in the cytoplasm near the nucleus in each of the cells of the
penultimate generation. This granule divides to two, which
become the blepharoplasts.
3. The two blepharoplasts, each with its aster, diverge to oppo-
site poles of the nucleus. During the early stages of separation a
distinct central spindle develops, so that an amphiaster is present.
4. The astral rays on the side toward the nucleus form two
cones of fibers which, when the nuclear membrane breaks down,
become the achromatic portion of the karyokinetic figure. The
blepharoplasts occupy the poles.
5. During the anaphases and telophases of karyokinesis the
blepharoplast enlarges, becomes vacuolate, and breaks up to a
number of pieces. After further fragmentation these unite to form
the cilia-bearing thread.
6. In the metamorphosis of the spermatid the nucleus and
blepharoplast elongate spirally side by side, but have no connection
other than that afforded by the undifferentiated cytoplasm.
7- The activities of the blepharoplast in Eguisetum, taken
together with the behavior of recognized true centrosomes in
plants and analogous phenomena in animals, are believed to con-
stitute conclusive evidence in favor of the theory that the blepharo-
plasts of bryophytes, pteridophytes, and gymnosperms are derived
ontogenetically or phylogenetically from centrosomes.
II4 BOTANICAL GAZETTE [AUGUST
The investigation here recorded was carried on under the direc-
tion of Professor JoHN M. Coutter, Dr. CHARLES J. CHAMBER-
LAIN, and Dr. W. J. G. LAND, to whom the writer wishes to express
his sincere thanks. He is also greatly indebted to Dr. SHIGEO
YamAnoucul for many helpful suggestions.
THE UNIVERSITY OF CHICAGO
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3
>
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7. ———, Ueber die —— in den spermatogenen Zellen. Jdem
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1912] SHARP—SPERMATOGENESIS IN EQUISETUM II5
17.
mal
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Griccs, R. F., The development and ison of Rhodochyirium. Bor.
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GuicNnarp, L., Developpement et constitution des anthérozoides. Rev.
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3°344-361. pls. To-I2. 1905.
116 BOTANICAL GAZETTE [AUGUST
39. GUILLIERMOND, M. A., Apercu sur l’évolution nucléaire des ascomycetes
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, Kerntheilung und freie Zellbildung im Ascus. Jahrb. Wiss. Bot.
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. ——, Cell division in sporangia and asci. Ann. Botany 13: 467-525.
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45. Hrrasé, S., Notes on the attraction — in the pollen cells of Ginkgo
biloba. Bot. Mag. Tokyo 8:359
is
rr
y
+
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47. Untersuchungen iiber das Verhalten des Pollens von Ginkgo
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48. Humpurey, J. E., Nucleolen und Centrosomen. Ber. Deutsch. Bot.
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ou
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Ig12] SHARP—SPERMATOGENESIS IN EQUISETUM II7
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a
oo
me
118 BOTANICAL GAZETTE [AUGUST
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EXPLANATION OF PLATES VII AND VIII
All figures were drawn at the level of the table with the aid of an Abbé
camera lucida under a Zeiss apochromatic objective 2mm. N.A. 1.40, with
compensating ocular 18. They have been reduced one-third in reproduction,
and now show a magnification of 2533 diameters.
PLATE VII
Fic. 1.—Cell of penultimate generation rounding off.
Fic. 2.—Deeply staining body with faint aster present in cytoplasm.
Fic. 3.—Division of small body in cytoplasm.
Fic. 4.—Two blepharoplasts formed by division of the original body.
BOTANICAL GAZETTE, LIV PLATE VII
BOTANICAL GAZETTE, LIV
PLATE VIilI
+ ie "te"
oo SS
Bs tnt 2h Us
RE eB
qowres
re ee
ean ’
Ee)
c
=
5at
~
.
03
&
ér
1
ae)
“
3
SHARP on EQUISETUM
1912] SHARP—SPERMATOGENESIS IN EQUISETUM IIQ
Fic. 5.—Blepharoplasts at upper side of nucleus; other single and paired
bodies present in cytoplasm; exceptional condition.
Fic. 6.—Blepharoplasts beginning to separate; central ne present;
the radiations on the side toward the nucleus form a distinct cone.
1G. 7.—Later stage; no cone of rays present.
Fic. 8.—Still later stage; central spindle fading out. ©
Fics. 9-12.—Stages in the divergence of the blepharoplasts.
Fic. 13.—Blepharoplasts lying at a greater distance from nucleus; the
radiations on the side toward the nucleus form two well marked cones; the
chromatin network becoming coarser.
1G. 14.—Spirem stage: nuclear membrane beginning to break down;
astral rays much shorter.
Fic. 15.—Late prophase: the spindle fibers have been formed from the
radia tis: of the blepharoplasts, which occupy the poles.
Fic. 16.—Telophase: blepharoplasts have enlarged and become vacuolate.
PLATE VIII
Fic. 17.—Pair of spermatids differentiated: blepharoplasts have the form
of — rings; plastids present in cytoplas
G. 18.—Spermatid: blepharoplast bedlecdas to fragment.
Fre 19.—Blepharoplast broken up to several pieces.
IG. 20.—Granules formed by fragmentation of blepharoplast beginning
to draw out into a row; nucleus again in resting condition.
Fic. 21.—Blepharoplast granules arranged in a long row; cilia beginning
to grow out from them; plastids present.
Fic. 22.—Blepharoplast granules fusing at right end of chain; still separate
at a seas degenerating plastids in cytoplasm
23.—Blepharoplast now a contiiabes thread; cilia partially
ee. nucleus beginning its metamorphosis.
Fic. 24.—Portion of a similar cell viewed from the direction a, showing
proximity of nucleus and blepharoplast; cilia not drawn
Fic. 25.—Later stage: nucleus and blepharoplast have elongated spirally;
chromatin network very coarse.
1G. 26.—Entire cell similar to that of fig. 25 viewed from the direction a,
showing independence of nucleus and blepharoplast; cilia not drawn.
Fic. 27.—Section of similar = in plane ab: m, nucleus; 0, blepharoplast;
cilia not drawn.
Fic. 28.—Mature spermatozoid still in antheridium: the blepharoplast
makes 1.4 turns, the nucleus 0.7 of a turn; deeply staining globules in cyto-
plasm near nucleus.
1G. 29.—Smaller spermatozoid in another antheridium, viewed from a
different policies
. 30.—Spermatozoid fixed in the swimming state over osmic fumes: the
dark spiral band bearing the cilia is the blepharoplast; the lighter, homo-
geneous portion the nucleus; the vacuolate portion the cytoplasm; length
exclusive of cilia, 19.7 u
THE PRIMARY COLOR-FACTORS OF LYCHNIS AND
COLOR-INHIBITORS OF PAPAVER RHOEAS"
GEORGE HARRISON SHULL
The frequency with which the presence of hereditary characters
is dominant over their absence naturally suggests that inhibiting
factors may be operating when the reverse relation appears to
exist, as when the hornless character of polled cattle dominates
over horns, and the “smooth” character over the ‘‘bearded” in
wheat, oats, etc. Some writers (DAVENPORT, BATESON, Powe
have even taken the extreme view that dominance is in all cases
a criterion of “presence.” That this position is untenable I have
shown several years ago (SHULL 11, 12), and CASTLE (2) also opposes
such an idea, calling attention to Woop’s well known sheep hybrids
(Woop 15), in which the horned condition is dominant in the male
and hornlessness in the female offspring from the same cross, as a
proof that no such sweeping generalization is permissible. It may
be granted, however, that presence is usually dominant, and that
the dominance of the apparent absence of a character is probably
in most cases, but not in all, the dominance of an inhibiting factor
over its own absence. It is only necessary to keep the mental
reservation that in any single instance of a putative inhibitor
another hypothesis is always available, namely, that the gene for
the character that is supposed to be inhibited, when existing singly
as in the heterozygote, may be nearly or quite incapable of reaching
the threshold of visible expression.
Both of the characters mentioned above by way of example—
the polled condition in cattle and the lack of long awns in wheat—
are structural characters. When a color-character is inhibited, the
* Under the title “Inhibiting factors in Lychnis and Papaver,” this paper was
read before the Botanical Society of America, Washington, D.C., December 28,
1911. The change of title and slike changes in the text isos been rendered
necessary by the discovery that the purple-flowered male parent of family 10201
discussed below was probably heterozygous in both the primary factors for color.
This discovery in no wise affects the general considerations presented in the papet
as read, but it withdraws Lychnis dioica for the present as an example of domi-
nant white.
Botanical Gazette, vol. 54] [120
1912] SHULL—LYCHNIS AND PAPAVER 121
result is a “dominant white” if the inhibition of all pigmentation
is practically complete, or there may result parti-colored forms
exhibiting various color-patterns, or the dominance of what appears
to be a lower grade of pigmentation over a higher grade when the
inhibition is localized or otherwise incomplete.
One of the earliest known and most familiar examples of domi-
nant white is found in the plumage of domestic fowl, in most breeds
of which white is epistatic to all colors, but not always quite per-
fectly so. It was soon found, however, that not all of the plumages
of white fowl are of the same nature, for the “‘Silkie”’ fowl’s white
plumage is recessive to colors. Dominant and recessive whites
have been discovered in a number of other cases, both in plants and
in animals. BATEsoN (1, p. 105) and Grecory (7) found that
white-flowered primulas with red stems are dominant whites,
while those with green stems are recessive whites;? KEEBLE,
PELLEW, and Jones (9), and Miss SAUNDERS (10) have demon-
strated dominant and recessive whites in Digitalis purpurea; and
East (4,pp. 81 f.) has shown that an inhibitor for blue aleurone-color
exists in some maize plants though absent in others.
In many cases, perhaps generally, the inhibition is not quite
complete, and dominant whites are often distinguishable by the
possession of patches or washings of color not found in recessive
whites. Similar incompleteness of action of genre is seen ly
the occasional appearance of rudimentary horns or “‘scurs” in
pure-bred polled cattle, in the development of a few feathers on
the legs of pure clean-legged fowls, the production of short awns
or “beards” on “smooth” wheat, oats, etc.
Not only are there dominant and recessive whites, but there
are also different kinds of these, dependent upon the fact, now
well known, that the same visible effect may be attained in various
ways. It has been demonstrated that pigmentation is generally
_ due to the interaction of at least two independent factors. When
only two such factors are required, e.g., C and R, there may be
three kinds of recessive whites, one lacking C, one lacking R, and
? While this is the general rule, Kress and PELtew (8) have found exceptions
in the variety “Pearl,” which has dominant white flowers and green stems, and in
“Snow King,” in which both dominant and recessive whites were found associated
with dark red stem
122 BOTANICAL GAZETTE [AUGUST
one lacking both C and R; and each of these whites will behave
differently in certain crosses, though all are recessive to colors
and may be quite indistinguishable from one another when pure-
bred. Individuals lacking either C or R, when crossed with other
individuals having the same genotypic constitution, or when crossed
with individuals of the third type, which lack both C and R, will
produce only white offspring; but when recessive whites of the
first two types are crossed together, the complementary factors,
C and R, necessary for the production of color, are brought together
and a colored F, results, as exemplified by the classic case of
‘Emily Henderson” sweet peas, in which two white-flowered
plants, differing externally only in the form of the pollen-grains,
produced ‘‘reversionary” purple offspring when crossed together.
Many similar ‘‘reversions” have been discovered by experimental
breeders in a considerable number both of plants and of animals,
and the old riddle of “reversion on crossing,” exemplified by these
phenomena, has been given a satisfactory solution in the ‘factor
hypothesis.”” In so many organisms have different kinds of reces-
sive whites been found, that their discovery in additional species
no longer occasions surprise.
Less is known of the chemistry of dominant whites, but it is
conceivable that these may also be of several kinds. It is plain
that any pigment which is readily converted into an allied colorless
compound would give a basis for a dominant white in which the
pigment nucleus coexists with a factor which changes it to its
colorless derivative. A suggestive illustration im vitro of such a
reaction is the ready reduction of indigo blue (CisH,.N,0.) in
alkaline solutions to indigo white (C,sH,,N.,0,). SPIEGLER (14)
believed that he had succeeded in isolating a ‘white melanin”
from white wool and white horsehair, and while GoRTNER (5; 6)
has been unable to confirm SpreGLER’s conclusions in this regard,
the general type of reaction suggested by SPrEGLER may be retained
as possibly explaining some cases of dominant white. GORTNER
(5) has proposed a very different hypothesis, namely, that as mela-
nin is the product of an oxidase acting on a chromogen (tyrosin),
dominant whites may be the result of anti-enzymes which inhibit
the action of the oxidase. The same hypothesis is applicable to
1912] SHULL—LYCHNIS AND PAPAVER 123
the widely distributed plant-pigment anthocyanin, whose method
of origin appears to be in essential agreement with that of melanin.
More recently GorTNER (6) has shown that anti-enzymes are not
necessary for the inhibition in question, as the oxidizing action of
tyrosinase is prevented by the presence of small quantities of such
relatively simple m-dihydroxyl phenolic compounds as orcin,
resorcin, and phloroglucin. GorTNER shows that on the basis of
his investigations a satisfactory explanation can be given of those
rare cases in which a white is dominant in some crosses and reces-
sive in others, as apparently exemplified by the Shirley poppies
described below.
I have been making numerous crosses among strains of Lychnis
dioica L., and during the past six years have grown about 660
pedigreed families of this species. Nearly 300 of these families
have resulted from matings between white-flowered individuals,
many of the matings having been arranged for the specific purpose
of finding different kinds of whites possessing complementary
color-factors. Until the past summer (1911) all of these crosses
between white-flowered parents have given uniformly white-
flowered progenies,’ and a similar number of crosses between white
and colored individuals have invariably shown the whites to be
recessive to colors, though they differed genotypically in that some
of the whites carried a factor for reddish-purple and others a factor
for bluish-purple, the red being epistatic to blue.
ith the bringing in of two new strains of Lychnis dioica
from their native habitats in Germany (for seeds of which I am
indebted to Dr. Baur), I have realized the complementary factors
for color for which I had been looking thus far in vain.‘
3 The several purple-flowered individuals from white-flowered parents, mentioned
in an earlier paper (SHULL 13), appear now to eth been plus-fluctuants of a “tinged
white” which had not been recognized as such at the time that paper was written.
They have no bearing on the problem of omnpisastany color-factors here under
consideration,
‘ That the several kinds of recessive whites exist among my Cold Spring Harbor
Strains, though I have not yet made a mating among them between two whites which
resulted in a purple-flowered F;, is sufficiently demonstrated by the facts presented
in my earlier paper. My failure thus far to secure a purple-flowered F, from two
whites among these strains must be due to the mere chance that I have not selected
whites from the proper families.
124 BOTANICAL GAZETTE [AUGUST
These two forms of Lychnis from Germany are with apparent
good reason classified by German taxonomists as distinct species,
the white-flowered form being called Melandrium album Garcke,
and the purple-flowered form M. rubrum Garcke. Melandrium
album, as it appears in my cultures, has relatively narrow, spatulate,
moderately ascending rosette-leaves of a rather dull dark green;
the corollas are white, slender, and long-exserted from the calyx-
tube; the styles are long and slender, with inconspicuous stigmatic
papillae. The plants are easily grown as annuals by early sowing.
Melandrium rubrum Garcke, grown under the same conditions,
has the rosette-leaves broader, with more rounded apices; the
leaves are nearly horizontal, a little darker green, and more shining.
The corollas are reddish-purple, shorter, scarcely extending beyond
the mouth of the calyx; the styles shorter and relatively heavy,
with prominent stigmatic papillae. A very small percentage of
the plants are forced to bloom as annuals, even when seeds are sown
early in February. In so far as visible characters are concerned,
these two forms have shown but slight fluctuations, except that
in M. album the calyx varies from plain green through green
striped with purple to a rather deep dull crimson. They have
kept quite distinct from each other in regard to the characteristics
enumerated, but because they breed together with undiminished
fertility and because I have many other strains showing similar
differences and various degrees of intermediacy, I must continue
for the sake of convenience the use of the Linnean name (Lychnts
dioica) for the entire aggregation. To what extent the other forms
in my cultures may have been derived from hybridizations between
M. album and M. rubrum cannot be surmised, but all strains which
I have thus far found in America have presented one or more
characteristics which are not directly traceable to either of the
German forms, nor obviously derivable from them by recombina-
tions of their characters. For instance, my original material of
this species, collected at Cold Spring Harbor, has considerably
lighter green foliage than either M. album or M. rubrum, and from
the vicinity of Harrisburg, Pa., I have secured a “chlorina”
(CORRENS 3) variety having light yellow-green foliage.
Three crosses were made in 1910 between the German Melan-
1912] SHULL—LYCHNIS AND PAPAVER 125
drium album and my original white-flowered strain from Cold
Spring Harbor. Two of these families (10200 and 10202) were
the result of crossing two different German white-flowered females
with pollen from a single Cold Spring Harbor white-flowered male.
Both of these matings produced only white-flowered offspring,
totaling 182 individuals. The young seedlings were indistinguish-
able from Cold Spring Harbor seedlings of the same age, but later
they became darker green and were intermediate between the
parents. A third family (1068) was essentially reciprocal to the
two just described, being produced by crossing a female sib of
the male used in 10200 and 10202 with pollen from a German
white-flowered male. The 77 offspring were vegetatively indis-
tinguishable from the reciprocal families, but the flowers were all
reddish-purple. These different results in supposedly reciprocal
crosses probably indicate that there was an unsuspected hetero-
geneity in the German strain. That the difference was due to
heterogeneity in the Cold Spring Harbor parental family is rendered
improbable by the fact that a mating (1060) between the female
used as the mother of 1068 and the male used as the father of
10200 and 10202 resulted in a progeny of 73 white-flowered plants.
It is unfortunate that a similar check was not applied to the German
plants entering into these families, by also crossing them together.
The only cross (10203) made between two specimens of M. album
resulted in 84 offspring, all white-flowered. The mother of this
family was also the mother of 10202, but the father was not the
same as the father of 1068.
Several crosses were also made between the purple-flowered
German Melandrium rubrum and my Cold Spring Harbor strains,
both white-flowered and purple-flowered. Families 1092 and 1093
were produced by crossing a single white-flowered female of the
Cold Spring Harbor strain with two males of M. rubrum, one
derived from seeds collected at Furtwangen in the Schwarzwald,
and the other from Oefingen in Baden. A female sib of the last-
mentioned plant (i.e., from Baden) was crossed (10204) with
pollen from a white-flowered sib of the mother of families 1og2
and 1093. It represented a cross, therefore, as nearly reciprocal
to 1093 as is possible in dioecious material. Two other families
126 BOTANICAL GAZETTE [AUGUST
(10206 and 10207) were produced by crossing two females grown
from the Baden seeds with pollen of a single pure-bred purple-
flowered male from Cold Spring Harbor. As Melandrium rubrum
has reddish-purple flowers and as this color has been shown to be
epistatic to bluish-purple (which may have been carried as a
latent character by the white-flowered plants), there was no reason
to expect that the F, progeny of any of these five crosses would
present any noticeable difference in flower-color from that of their
M. rubrum parent. This expectation was realized, the 262 off-
spring from these crosses all having reddish-purple flowers. The
young plants in these families were generally indistinguishable
_ from pure-bred M. rubrum, but later they differed by being notably
more vigorous, having enormous rosettes of broad, shining, dark-
green leaves. They were also much more easily grown as annuals
by early sowing, being in this regard intermediate between the
parents. Almost all of the hybrids were blooming by the middle
of July, before the first flowers of any pure M. rubrum had opened.
Compared with these crosses between Melandrium rubrum and
the Cold Spring Harbor plants, a cross of M. rubrum with M. album
gave a totally different and unexpected result. A mating between
a female of the white-flowered album and a purple-flowered male
rubrum produced an F, (10201) consisting of 23 white-flowered
individuals and 3 (probably 4) purple-flowered ones. The white-
flowered plants were unlike either parent in vegetative characters,
having relatively short, sharp-pointed, grayish-green leaves which
were strongly ascending in the fully developed rosette, while
both parents have long, spreading, dark-green leaves. The flowers
were not only white like those of their white-flowered mother, but
they were also nearly identical with them in form. It was noted
that rarely some of the flowers became faintly and unevenly
streaked and washed with purple just as they were fading, a
feature never observed in the flowers of any of my other white-
flowered plants. These white-flowered hybrids were a little later
in blooming than their white-flowered parent, but were still easily
induced by early sowing to behave as annuals. The purple-
flowered offspring of this cross were of an altogether different
character, and were not readily distinguishable in rosette and
1912] SHULL—LYCHNIS AND PAPAVER 127
floral characters from their purple-flowered male parent.. They
were also like pure M. rubrum in not blooming until late in the
season. One plant having a rosette identical with those of the
three purple-flowered specimens remained a rosette, but will
doubtless have purple flowers if it survives the winter.
Why there should be this segregation of types in the F,, and
why one of these types should so completely resemble the male
parent, while the other type was goneoclinic to the female parent,
though abundantly distinct from it in the rosettes,-are mysteries.
Perhaps this unexpected segregation of characters in a putative F,
is further evidence of the heterogeneity of the M. album material.
If the white-flowered mother were heterozygous in a dominant
white factor, the expected result of a cross with M. rubrum would
be 3 white-flowered to 1 purple-flowered, or in this particular
family 20 white-flowered to 7 purple-flowered, to which expectation
the observed result is in sufficiently close agreement considering
the small number of individuals. The same result would be
attained if the rubrum parent were heterozygous in respect to
both the primary factors for color, C and R, it being assumed
that the album parent lacked both these factors. No other evi-
dence of heterogeneity in M. rubrum has yet appeared in my
cultures. It should be remarked that neither of these German
strains had been pedigreed in controlled cultures, but were simply
collected in separate regions in nature, so that questions as to
their genotypic purity are legitimate.
In the derivatives of the corn-poppy (Papaver Rhoeas L.),
among which are the dainty and beautiful ‘‘Shirley”’ poppies of
our gardens, color-inhibitors are also found. According to his own
statement; Rev. W. WILKS was first induced to pursue the course
of selection, which resulted in the strain known as the “Shirley
poppies,” by discovering a bud-variation on a wild corn-poppy
growing in a corner of his garden. Several flowers on this plant
differed from the rest in having petals with a narrow white margin.
Such a white margin is now a frequent feature of garden poppies,
and when appropriate crosses are made, it is found that the presence
5 Note added ier 5, t912. This plant is now blooming and has purple
flowers as predicted
128 BOTANICAL GAZETTE [AUGUST
of a margin is dominant over its absence. It is probable, therefore,
that the white margin is due to the presence of an inhibitor whose
action is localized in the margins of the petals.
In 1911, among 73 pedigreed families of Papaver Rhoeas grown
at the Station for Experimental Evolution, 45 resulted from crosses
between plants of which the presence or absence of a margin had
been recorded, and of which a goodly proportion of the offspring
were capable of being similarly recorded. The rest either had one
white-flowered: parent whose possession (or lack) of a margin
could not be determined by inspection, or for some other reason one
or both parents or the offspring could not be safely characterized
with respect to margins. Of the 45 families having the margins
of parents and offspring recorded, 3 represented crosses between
plants both of which had margined petals, 17 were from crosses
between one margined and one unmargined parent, and 25 re-
sulted from matings between plants none of which had margined
petals. The three families from matings between margined parents
consisted of 236 individuals, including in each family a mixture of
plants with margined and with unmargined petals. Records
of the margins were often impossible, owing to the interference of
other factors not yet fully investigated, so that the numbers
of each type of offspring have no special significance in the present
connection and they will be reserved for discussion at another
time.
Of the 17 families produced by mating plants with margined
and with unmargined petals, 12 were composed of a mixture of
plants, some with margins and some without, 3 contained only
plants with unmargined petals, and in 2 families practically all of
the individuals had margins. With margins dominant over their
absence, only two kinds of families were to be expected from this
type of mating, namely, all margined if the margined parent
chanced to be homozygous, and mixtures of plants with margined
and unmargined petals if the margined parent was heterozygous.
The three families (10272, 10273, 10274) in which no margins
appeared, though one of the parents had a margin, are exceptions.
One margined individual was the mother of all three of these
exceptional families. The records show that this plant differed
1912] SHULL—LYCHNIS AND PAPAVER 129
from the usual type, the margin being in this case red-violet® instead
of nearly white. Whether this red-violet margin was a purely
somatic modification of the dark-red body-color, or whether it
was germinal, it was clearly of a different nature from the white
margins involved in the other families.
In the two families (10287, 10289) whose margined parents
were evidently homozygous, a small number of plants were recorded
without margins. These exceptional plants occurred among those
set into the garden, while larger numbers of plants from the same
families, which were grown to maturity in pots in the propagating-
house, were all margined. In family 10287 there were 6 plants
with unmargined petals among 40 grown to maturity in the garden,
and none among 133 which flowered in pots, and in family 10289
one was noted as unmargined among 47 plants in the garden and
none among 83 which developed in pots.’ However these seven
unmargined specimens are to be accounted for, it is clear that
each of these families is the offspring of a homozygous margined
parent.
In the 25 matings between plants, neither of which possessed
margined petals, there appeared only 15 plants with margins
among a total of 1402 offspring, and in a number of those recorded
as margined the margin was merely a trace of lighter color of more
or less doubtful character. Only in one family (10291) were the
margins unmistakable, and in this family the margined plants
occurred only among those which were retained in the greenhouse.
Of 21 which matured in the garden none had margins, while among
99 which flowered in pots in the greenhouse there were 10 with
margins, several having only a trace, while others had well marked
white margins 2 mm. wide—in one plant 3 mm. wide. No attempt
need be made at present to account for these few margined plants,
for their number is too small to vitiate the conclusion that the
unmargined condition is recessive, and that typically all the
offspring of two unmargined parents are unmargined.
The most interesting matings in which margins were ‘eck
° The color-nomenclature adopted in this opis . based sess = mauris ier
as arranged in the Milton Bradley system
but for the sake of simplicity these ie: not been reproduced here.
130 BOTANICAL GAZETTE [AUGUST
were those in which the wild poppy was crossed with its garden
derivatives, for as already noted the margin is a new character
which does not normally occur in the wild poppy. In the two
families representing such matings, the wild poppy was used as
the mother in 10298 and as the father in 10310. Both families
consisted of mixtures of margined and unmargined plants, showing
conclusively here also that margined petals is a dominant character,
since the wild plants are certainly homozygous in the lack of such
margins. The dominance of the margined condition of the garden
poppies over the unmargined condition of their wild prototype is
in marked contrast to all the other color-characters of Papaver
Rhoeas yet investigated, for the dark red-orange body-color’ of
the wild poppy is epistatic to all the body-colors presented by
the numerous garden forms. If dominance were a secure criterion
of the presence of a gene which is absent in the recessive type,
these results would indicate that while the various body-colors
of the garden forms originated as retrogressive mutations, 1.€.,
by losses of characters, the white margins of the petals represent
a progressive mutation through the addition of a gene which
inhibits the development of color in that region. Doubleness
also proves to be dominant over the single type of the wild poppy,
and, on the basis of the same assumption, would have to be classed
as a progressive mutation. I cannot forbear, however, to repeat
the caution that dominance does not necessarily demonstrate the
progressiveness of a mutation, since the alternative hypothesis,
mentioned above in the first paragraph, allows for the dominance
of a character which has originated by a retrogressive mutation.
There is still one other color-inhibitor (possibly several) in
the derivatives of Papaver Rhoeas, which is in some respects more
noteworthy than that which produces the white margins. This
affects the body-color of the petals, producing what is essentially
a dominant white, though in this case the inhibition is not usually
complete and the flowers often show some irregular striation of
dull violet, reddish, or bluish color on the petals, especially in
the presence of purple stamens.
7 By the expression ‘‘body-color”’ it is intended to indicate the color of the general
intermediate region of the petals as distinct from “center’’ (proximal) and “ma: argin
(distal).
1912] SHULL—LYCHNIS AND PAPAVER 131
A single white-flowered plant with yellow stamens was crossed
in 1909 with three red-flowered plants (yielding families 10275,
10281, 10282) and with two plants having dull striations on the
petals (families 10280, 10283), and thé offspring of these five matings
were generally white or whitish-flowered. Of 559 plants in these
families only 25 were neither pure white nor white with traces of
reddish color, and of these 25, all that had a full red (i-e., not
striated) parent were lighter in color than that parent. These
fully pigmented offspring may simply represent minus-fluctuations
in the action of the inhibitor derived from the white-flowered
parent. If this is the correct interpretation of these few plants
with colored flowers, it should be possible to secure from them
progenies displaying the presence of the inhibitor though it be
invisible in both parents. While I have as yet grown no offspring
from the colored plants of these families, I have two other families
(10270, 10308) in which the same whitish offspring have appeared,
though both parents in each case were fully pigmented. Family
10270 was produced by mating two dark-red parents which were
sibs in a family consisting of red, red-orange, pink (light violet-
red), and white. The progeny of these two dark-red plants con-
sisted of 68 white or whitish and 70 pigmented, the latter often
striated and generally much less intensely pigmented than either
parent. Only two of the offspring showed as deep shade as that
of their parents. The parents of family 10308 were also red-
flowered sibs in a family containing red, red-orange, pink, and white.
They were considerably lighter red than the parents of 10270, but
were fully and evenly pigmented. Their offspring consisted of 80
white- and whitish-flowered plants and 13 with pigmented flowers,
none of which were as deeply pigmented as either parent, and
several of which showed the peculiar striation which seems to be
one of the manifestations of the inhibitor believed to be operating
in these crosses. Similar results were obtained in seven families
(10266, 10273, 10274, 10297, 10303, 10305, 10311) produced from
mating together two plants with striated petals, or a striated with
a plain red, and only in one family, containing three individuals
(10268), did the “dominant white” fail to manifest itself in pro-
genies from matings of this character. In the latter family a
132 BOTANICAL GAZETTE [AUGUST
cross between a light-red and a striated individual produced three
offspring, all with flowers slightly darker red than those of their red-
flowered parent. Considering the complexity of some of these
families, this number of individuals is entirely inadequate for
the deduction that family 10268 was really exceptional.
While I have laid no emphasis thus far on the fact, it may have
been noted that all of these poppy-families in which a ‘‘dominant
white” has made its appearance have been derived from red or
striated parents, never from red-orange or pink (light violet-red).
It seems that the factor under discussion is not a general inhibitor
of color but only of pure spectrum-red. The following facts seem
to prove this: The same white-flowered plant with yellow stamens
which we have seen producing white-flowered progenies when
mated with red (families 10275 and 10281) was also mated with
two homozygous pink-flowered plants (families 10277 and 10278)
and a homozygous red-orange plant (10279) and in all of these
three crosses the white-flowered parent proved to be a recessive
white. Families 10277 and 10278 consisted of 43 pink-flowered
and 25 red-flowered plants, and 10279 contained 226 red-orange-
flowered plants and 1 red-flowered. Not a single individual in
any of these three families had white or whitish flowers. In
keeping with these results are families in which striated plants
were mated with pink (10295) and red-orange (10301), for in
neither of these families appeared a white-flowered offspring or
one with striations, 10295 yielding 37 pink-flowered and 33 red-
flowered and 10301 giving 22 which were red-orange and 5 inter-
mediate between this and red.
The occurrence of many red-flowered plants in these families,
when one of the parents supposedly contained an inhibitor for
red, is not satisfactorily explainable on the assumption made
above, that there is a single inhibitor for red whose effectiveness
fluctuates to such an extent that its presence may not be detected
' in its extreme minus-fluctuations. An alternative hypothesis may
be suggested, which must await further experimentation for its
confirmation or rejection. If there be two factors, A and B,
which are ineffective when existing apart from each other, but
which become an inhibitor when acting together, the observed
1912] SHULL—LYCHNIS AND PAPAVER 133
results could be explained by assuming that in those matings which
produced whitish-flowered offspring, the one parent possessed A,
the other B, while in those matings in which a fully pigmented
progeny was produced, the two parents had the same factor—either
both A or both B—or else one of them lacked both A and B and
the other parent lacked one of them. The occurrence of fully
pigmented individuals in association with ‘dominant whites”
need not then be minus-fluctuations of a single inhibitor, but
might be the result of segregation of inhibiting factors, one or
more of which were heterozygous in one or both parents.
Summary
Dominant and recessive whites have been discovered in a
number of different plants and animals. Both the dominant
whites and the recessive whites may be of different kinds, though
externally indistinguishable.
Dominance does not necessarily indicate presence of an added
gene, but when the absence of a character appears to be dominant
over its presence, the action of an inhibiting factor may usually
be inferred. An alternative hypothesis is always available, how-
ever, which should prevent a too dogmatic assertion that dominance
is synonymous with presence.
A white-flowered form (Melandrium album) of Lychnis dioica L.
from Germany, when crossed with the purple-flowered form (M.
rubrum) from the same country, produced 23 white-flowered and
4 purple-flowered offspring, but in certain crosses with a white-
flowered strain derived from plants growing at Cold Spring Har-
bor, the German white-flowered plants produced purple-flowered
offspring in the F,, in other crosses only white-flowered offspring
were produced.
In the “Shirley” poppies (Papaver Rhoeas L.), the presence of
a white margin of the petals is a dominant character and is probably
due to an inhibitor limited in its effective action to the margins
of the petals.
These white margins and doubleness of the flowers are the only
characters in the garden poppies which were found dominant over
the corresponding characters of the wild type from which they
134 BOTANICAL GAZETTE [AUGUST
were derived. They may represent the results of progressive
mutations, but here again caution is necessary because of the
alternative hypothesis.
There is also an inhibitor which affects the body of the petals
in the “Shirley” poppies, producing what is essentially a dominant
white, though the inhibition is often very imperfect, in which case
the flowers are more or less washed and striated with color, though
generally whitish.
This supposed inhibitor was evident only in crosses involving
at least one red-flowered or striated parent. The same white-
flowered plant which was a dominant white in crosses with red-
_ flowered and striated plants was a recessive white in crosses with
pink-flowered and red-orange-flowered plants.
In several cases red-flowered plants crossed together produced
a whitish progeny and a similar result was produced when two
striated plants were mated or when striated was crossed with red.
Two hypotheses to account for these facts are considered:
(a) that there is one inhibitor affecting only the pure spectrum-red
and having no effect on pink and red-orange; the minus-fluctua-
tions of this inhibitor pass the limit of visibility; (6) that there are
two factors, A and B, which have no visible effect when existing
alone, but which act as an inhibitor when brought together. These
two hypotheses must be tested by further breeding.
I take pleasure in acknowledging here the faithful work of
Mr. E. E. Barker, who assisted me in making the records upon
which this paper is based.
STATION FOR EXPERIMENTAL EVOLUTION
OLD Sprinc Harsor, L.I.
LITERATURE CITED
1. Bateson, W., Mendel’s principles of heredity. Cambridge: University
Press. 1909.
2. CasTLe, W. E., Heredity in relation to evolution and animal breeding.
New York: D. Appleton & Co. rgr1.
3. Correns, C., Vererbungsversuche mit blass(gelb)griinen und bunt-
blattrigen Sippen bei Mirabilis Jalapa, Urtica pilulifera, und Lunaria
annua. Zeitschr. Ind. Abst. Vererb. 1: 291-329. figs. 2. 1909.
1912] SHULL—LYCHNIS AND PAPAVER 135
4. East, E. M., seit in maize. Bull. 167, Conn. Agr. Exp. Sta.
pp. 142. pls. 25. 19
GORTNER, R. A. Sia ‘“‘white melanin” as related to dominant and
recessive whites. Amer. Nat. 442497. I9I10
, studies on melanin: III. The ehiiitory action of certain phenolic
pbtances upon tyrosinase. Jour. Biol. Chem. 10:113-122. IgII.
- Grecory, R. P., Experiments with Primula sinensis. Jour. Genetics
1273-132. pls. 3. figs. 2. IO1t.
. Keeste, F., and PELLEW, Miss C., White-flowered varieties of sucess
sinensis. foe Genetics 1: 1-5.
9. KEEBLE, F., PELLEW, Miss C., and Jor , W. N., The inheritance of
peloria and ds téecclor 3 in foxgloves Dieisalis sisi’, New Phytol.
& 2
LP See eae |
R., On inheritance of a mutation in the common
foxglove (Digitalis purpurea). New Phytol. 10:47-63. pl. 1. figs. 14.
al
9
Nn
j
I
Ps
wm
7
wm
4
IQII.
11. SHutt, G. H., The “presence and absence” hypothesis. Amer. Nat.
43: 410-410. T90
12. os bole. chemical ers to ease Mendelian inheritance.
Plant World 12°145-153. $i.
, Color inheritance in Lychnss dioica L. Amer. Nat. 44:83-91. 1910.
14. SPIEGLER, E., Ueber das Haarpigment. Beitr. Chem. Physiol. Path.
4:40. 1904.
15. Woop, T. B., Note on the inheritance of horns and face-color in sheep.
Jour. Agr. Sci. 1: 364. 1906.
CONTRIBUTIONS FROM THE ROCKY MOUNTAIN
HERBARIUM. XI
NEW PLANTS FROM IDAHO
AVEN NELSON
(WITH TWO FIGURES)
The papers in this series numbered IX and X both dealt with
novelties secured by Mr. J. FRancis MAcBRIDE, of New Plymouth,
Idaho, in his collections of 1910. The region that proved of great-
est interest during that season was certain portions of Owyhee
County in the southwestern part of the state. However, he found
it possible to visit other counties, and in all of them much of interest
was secured.
He spent the season of 1o11 also in the field, revisiting some of
the favored localities at earlier dates, and going into new fields
later in the season. The writer found it possible to join MACBRIDE
in his work during the month of July, at which time certain of the
lava lands of southern Idaho were investigated. A few days were
spent also in the Sawtooth and in the Lemhi National forests.
This and a succeeding paper will deal with some of the many inter-
esting things that were found. The plants to be sent out will bear
MACcBRIDE’s numbers, but those secured while both were in the
field will have both collectors’ names upon the labels.
Sisyrinchium inalatum, n. sp.—Roots coarsely fibrous, in-
ordinately numerous from the small cormlike rhizome, widely
spreading: stems simple, tufted and crowded, erect, 3-4 dm. high,
rather stout, wholly wingless, leafy below, more than twice as long
as the longest leaf, about ro-striate: leaves g—15-nerved, hyaline-
margined at the middle only where they are often 6-8 mm. broad,
the upper half somewhat divergent, either straight or somewhat
arcuate: the outer spathe large and conspicuous, 4-6 cm. long,
many-nerved, at its widest part (where it is more or less scarious-
margined) 8-10 mm. broad, tapering gradually to the apex, usually
surpassing even the mature umbel by nearly half (sometimes more),
Botanical Gazette, vol. 54] [136
1912] NELSON—IDAHO PLANTS 137
the upper one-fourth closed: inner spathe 6—8-nerved, with inter-
mediate nerves, the whole margin broadly hyaline, less than half
as long as the outer and shorter than the mature pedicels: scales
thin, silvery scarious, from half to nearly as long as the inner spathe,
the primary one with 3 conspicuous green nerves: flowers 1-4,
medium size, seemingly purple or purplish (the material at hand
quite mature and the flowers out of condition): stamineal column
short: pedicels erect, 25-45 mm. long: capsules 5-6 mm. long,
obovoid-globose but evidently trigonous, pale green: seeds about
I5, 2 mm. long, flattened-oval, sometimes slightly trigonous or
rhomboidal but always compressed and more or less wing-margined,
and rugulose-pitted.
It is not clear to what species this is most nearly allied, but it is so strongly
marked by its mass of fibrous roots, its stout wingless stems, its broad leaves
and spathes, and its large capsule and numerous large winged seeds, that its
recognition is not difficult.
MACBRIDE’S no. 909, Silver City, June 17, rort, is the only collection at
hand. This, singularly enough, was secured on a dry open hillside.
Eriogonum shoshonensis, n. sp.—Annual, 1-2 dm. high, more
or less white-lanate throughout and densely so on the under side
of the leaves: stems few to several from the base, slender, dichoto-
mously or tricotomously branched, the lower internode rather long,
the succeeding ones gradually shorter, all the branches rather
closely erect and therefore appearing fasciculately crowded above: -
leaves open-rosulate, 1-2 cm. long, on slender petioles as long or
longer: bracts minute, triangular-subulate: involucres sessile, in
the forks and lateral, and rather numerous on the branchlets,
firm and somewhat angled by the thickened greenish nerves that
terminate in the very short teeth, nearly tubular, about 2 mm. long,
5-1o-flowered: perianth glabrous, on slender unjointed filiform
pedicels which protrude about 1 mm.; perianth segments pinkish-
white, with greenish midrib, obovate, obtuse, 2 mm. long, the outer
noticeably broader than the inner: achene ovoid-triangular,
abruptly contracted into a rather slender beak, nearly as long as
the body, both together as long as the perianth.
’ Probably most nearly allied to E. iruncatum T. & G. Proc. Amer. Acad.
8:173, but differing essentially in habit. That may perhaps best be described
138 BOTANICAL GAZETTE [aveusr
as stemless, with a short stout peduncle from the summit of which spring few-
several foliar-bracted rays which are then dichotomous or trichotomous. The
involucre of that species is tubular campanulate
Secured by NEtson and MacsripE at Sicahdne: Idaho, in the rich lava
soil of sagebrush swales, July 18, no. 1186.
Polygonum emaciatum, n. sp.—Very slender glabrous silver-
green annual, 15-40 cm. high: stem usually simple below but
branching dichotomously from near the base and upward, the
internodes rather long, noticeably geniculate at the nodes so as to
give the stems and branches a zigzag aspect: leaves few, linear,
revolute, short, or even reduced to mere bracts: sheaths scarious,
irregularly lacerate into a few acuminate awns: flowers in slender,
rather open, terminal, spicate racemes; 1 or 2 in the axils of the
small bracts which are more or less concealed by the lacerate
sheaths; pedicels short, slender, erect, not exserted: perianth
segments obovate-cuneate, whitish with a red line, about 3 mm.
long: ovary oblong, triangular, as long as the slender styles:
mature fruit not at hand.
This suggests P. tenue Michx., from which its peculiar skeletonized appear-
ance, its zigzag branching, its very small not cuspidate leaves, and its usually
solitary white flowers easily separate it.
he type is MAcBRIDE’s no. 1692, ‘“‘doby” lava slopes, near Sweet,
Idaho, August 14, 1911; also by JuNE CLarK, August 18, no. 269, in the
same locality.
Loeflingia verna, n. sp.—A diminutive, vernal, glabrous annual,
1-5 cm. high, with short filiform root: stem simple or with few-
several filiform ascending branches: leaves triangular-subulate,
not cuspidate, 2 mm. or less long, opposite at the few nodes: flowers
few, solitary-axillary on rather long filiform pedicels forming an
open few-flowered cyme: sepals 5, entire, about 3 mm. long,
lanceolate, acute, scarious-margined, 1-nerved but neither carinate
nor setaceous tipped: petals usually wanting, if present scarious,
narrowly lanceolate, as long as the sepals, apparently 3 only:
stamens 3 or rarely 5: anthers small, on capillary filaments, stigmas
3 (or 2?), subsessile but distinct: ovary several-ovuled; capsule
1-celled, ovoid-triangular, as long as the sepals: seeds attached to
the central-basal placenta on rather long funiculi: embryo moder-
ately curved, accumbent.
>
1912] NELSON—IDAHO PLANTS 139
It is interesting to add another American species to this singularly erratic
genus. I have no doubt that the describer of L. pusilla Curran was right in her
observation ‘“‘stamens 5,” in spite of the fact that later observers have noted
only 3. The plants now at hand show this tendency to vary the number of
stamens, and occasionally to develop petals also. Is the following statement
of the manuals correct, “ovules attached laterally,” or does the wording in this
description come closer to the fact ?
Secured by Macprive in the grass among the sagebrush, on the plains
near New Plymouth, April 24, ror1, no. 773.
ARABIS LIGNIPES impar, n. var.—Larger and coarser than the
species (A. lignipes A. Nels. Bot. Gaz. 30:191. 1900), the lignescent
caudex apparently more enduring, often 8-10 cm. high and marked
only by the scalelike leaf bases: pubescence extending to the
inflorescence and mature pods.
The type of this variety is MACBRIDE’s no. 828, dry, stony slopes, on Squaw
Creek, Sweet, Idaho, May 8, 1011. Irefer here also specimens by C.N. Woops,
Hailey, Idaho, no. ga, 1910.
DRABA LAPILUTEA A. Nels. in Coult. & Nels. Man. 222. 1900.
D. yellowstonensis A. Nels. Bot. Gaz. 30:189. 1900.—Fine speci-
mens of this strongly marked species were secured by NELSON and
MacsripE on a high mountain near Mackay. It accords very
closely with the type except that some of the specimens indicate
that it may sometimes at least be perennial. The flowers are
truly white and not merely so on fading.
Draba McCallae and D. columbiana Rydb., Bull. Torr. Bot. Club 29: 241.
IQOI, are very near allies, if indeed they be not both referable to D. lapilutea.
Parrya Huddelliana, n. sp.—Perennial from very long slender
flexible woody roots which penetrate far down among the rocks in
subalpine slides: caudex of few-several very slender (almost
filiform) somewhat scaly branches which elongate (even to several
dm.) sufficiently to bring the herbage out among the surface rocks:
leaves rosulate on the tips of the branches of the caudex, with some
scales or petioles for a few cm. below, narrowly spatulate-
oblanceolate, 12-25 mm. long, somewhat cinereous with a stellately
branched pubescence: inflorescence a short crowded corymbose
raceme almost hidden among the leaves but the pedicels elongating
in fruit, the few-several large pods appearing umbellate upon rays
10-15 mm. long: pods oblong or bicuneate, 2-3 cm. long, the acute
140 BOTANICAL GAZETTE [AUGUST
apex tipped with the short, slender, obscurely lobed stigma, very
flat, with perfect septum and the few large seeds in two rows: seeds
oval, silvery-white, with a crisped or cellular seed-coat.
To find so perfect an example of a true Parrya in this region was a most
agreeable surprise. It is nearer to P. arctica R. Br. than to P. macrocarpa
R. Br.
This fine species was discovered by Cotumpus I. Huppte, supervisor of
the Lemhi National Forest, Mackay, Idaho. It was growing in the loose
black-limestone slide-rock, in Bear Canyon, altitude about 10,000 feet. The
specimens, secured in good quantity, were in full fruit. The species is named
for its discoverer, to whose courtesy the writer owes the memory of a glorious
summer day’s splendid collecting in the forest, under Mr. HuppLe’s watchful -
supervision, July 30, 1911. Distributed under NELSON and MAcBRIDE’S
no. 1466.
CHYLISMA SCAPOIDEA seorsa, n. var.—Annual or winter annual,
green and glabrous in appearance but minutely puberulent on stems
and in the inflorescence: stems branching from the base and upward,
2-3 dm. high, equally leafy up to the rather long naked open raceme,
the basal leaves falling away sooner than the upper: leaves oblong
to ovate or even obovate, entire or denticulate with callous-tipped
teeth
The best example of this at hand is AVEN NELSON’s no. 4125, Evanston,
Wyo., July 27, 1897. NEtson and Macsripe’s no. 1145, King Hill, July 16,
rgrt, is also referable to this variety.
Taraxia tikurana, n. sp.—Perennial from long, and in older
plants, rather thick fleshy roots with 1-3 crowns, strictly acaules-
cent, green but under a lens sparsely and minutely appressed
hirsutulous: leaves 8-15 cm. long (including the petiole), narrowly
oblanceolate in outline, pinnately deeply and irregularly toothed,
the rounded sinuses often extending to the midrib; the slender
petiole shorter than the blade: flowers rather numerous, yellow; the
calyx tube 6-10 cm. long, slender: calyx lobes narrowly lance-
oblong, about 8 mm. long, twice as long as the obconic tube: petals
large, obovate, emarginate or rounded, 1o-14 mm. long: stamens
unequal, the shorter stamens only about half as long as the others;
anthers attached about one-third of their length from the base:
capsule small, subulate, ridged by the rounded sutures; seeds in
two rows, irregularly oblong.
1912] NELSON—IDAHO PLANTS 141
This splendid species is nearest to T. breviflora Nutt., from which it is so
different that there is no need to emphasize the differences.
MaAcsrivE secured it in Jordan Valley, near Silver City, June 22, 1911;
NELSON and MAcBriDE’s no. 1302, from Tikura, Blaine Co., is taken as the
type. It seems to occur in the rich soil of river bottoms.
Cicuta cinicola, n. sp.—TIFrom a thick stout root (?)' widely
and freely branched, 2 m. (more or less) high: leaves large; the
lower often 1 m. long, bipinnate with some of the larger pinnae
trifoliate, gradually reduced and simplified upward, the uppermost
very small and trifoliate
or simple; the leaflets of
the lower leaves from ovate
to broadly lanceolate, 12—
20 cm. long including the
long stout petioles, coarsely
serrate, the teeth broadly
triangular and abruptly
apiculate; upward the
leaflets become gradually
smaller and narrower, the
uppermost lance-linear and
only 2-3 cm. long; invo-
lucre wanting or of a few
green or rarely scarious-
margined bracts, or some-
times a single foliar bract
2-4 cm. long: pedicels
numerous, 3-7 mm. long; Fic. 1.—Cicuta cinicola A. Nels., n. sp.
the involucels of many
lance-linear, scarious-margined bractlets, as long as or longer than
the pedicels: fruit strongly compressed laterally, the dorsal diameter
twice as great as the lateral, about 3 mm. long, the stylopodium
low-conical, the styles about 1 mm. long: the carpels somewhat
oblique at base and more or less inequilateral: the low rounded
ribs in surface display about equally the intervals in which lie the
large irregular solitary oil tubes; commissural face plane, rather
narrow, with two smaller oil tubes (fig. 1).
The root was not collected, but the impression of the collectors is that it was too
large and deep-set to be removed with the means at hand.
sf J
“SG @ See @-
SS nee Py
Y1 \
4 |
ve
142 BOTANICAL GAZETTE [AUGUST
This species is singularly like C. Bolanderi Wats., except for the much
larger leaves and the large broad leaflets. The fruit, however, is much more
flattened dorsally and the pericarp much thickened with strengthening tissue.
It is extremely improbable, however, that the species heretofore supposed to
be restricted to the tide-land marshes of Suisun, Cal., should next appear in the
lava lands of Idaho.
The plants are large, stately, well branched, and conspicuous objects
among the underbrush that borders Rock Creek, near Twin Falls. The stem
at the base is often 4-5 cm. in diameter. The soil in this neighborhood is the
well known volcanic ash that has proven so well suited to the production of
apples. NE tsoN and Macsripe’s no. 1315, July 25, 1911, is the type.
Cynomarathrum Macbridei, n. sp.—Glabrous: acaulescent:
root woody, surmounted by a branched caudex which is clothed
lh
"
LF)
naens
ely
ite
Fic. 2.—Cynomarathrum Macbridei A. Nels., n. sp.
with dead leaf bases: leaves narrowly oblong, bipinnate, 3-7 cm.
long including the very slender petiole; the pinnae often pinnately
cleft; the leaflets elliptic, very numerous and minute, only 1-2 mm.
long: scapes 1-3 times as long as the leaves, slender: the flowers
closely capitate in a small cluster, white: rays few and short (only
a few mm.) even in fruit: pedicels nearly wanting: seeds flattened
dorsally, all of the ribs thin-winged, the lateral more than half as
broad as the body, the others not much narrower: oil tubes 3-5 in
the intervals, 4-8 on the commissural side: calyx lobes evident:
the stylopodium low and flat (fig 2).
This species is decidedly distinct from any of the known species in this
genus. Some of its characters suggest the genus Phellopterus, but the char-
1912] NELSON—IDAHO PLANTS 143
acteristic caudex and the presence of the stylopodium leave scarcely any doubt
that it is a Cynomarathrum.
Secured by Macsripe in the shale slides near the summits of the moun-
tains bordering Bear canyon, in the Lemhi National Forest, July 31, 1911, no.
1502.
DODECATHEON PAUCIFLORUM shoshonensis, n. var.—Similar to
the species in size, but the root system consisting of a short corm
from which the fleshy-fibrous roots seem to detach at the end of the
season, at which time there has formed laterally on the corm 1 or 2
elongated bulblike buds. These probably give rise to the next
year’s plants. The flowers are paler than in the species.
The material at hand is rather scanty and over-mature. Possibly ampler
collections may show further differences. The specimens were secured by
NELSON and MacsripeE at Shoshone Falls, July 26, rg11, no. 1362
Phacelia firmomarginata, n. sp—Annual or possibly biennial,’
divaricately branched from.the base, with assurgent branched
stems 1-2 dm. long: pubescence short, fuscous, obscurely glan-
dular, with some small scattering hispid hairs which are most
numerous on the calyx: leaves alternate, rather small, 1-4 cm.
long, sessile or short-petioled, oblong in outline, pinnately cleft or
parted into few ovate or obovate crenulate-toothed lobes: the
ebracteate spikes dense even in fruit, 3-6 cm. long: calyx decidedly
enlarged in fruit, apparently persistent, cleft to the base and only
loosely inclosing mature capsule; sepals narrowly oblong-lanceolate,
at maturity about 1 cm. long, reticulated by the veins which run
from the stout mibrib to the greatly thickened firm hispid margins:
corolla minute, pale or white, much shorter than the calyx, the
rounded denticulate lobes about half as long as the short broad
tube, the vertical folds obsolete; stamens and style well included:
capsule ovoid, minutely hispid-pubescent, 3-4 cm. long, seeded:
seeds oblong, about 2 mm. long, brown, distinctly pitted.
Probably nearest P. hispida, from which it is quite distinct. It is a plant
of the desert, being secured by MAcBRIDE on dry hillsides near Twilight Gulch
in Owyhee County, June 23, 1911, no. 979.
PHLOX LONGIFOLIA filifolia, n. var.—The woody caudex short,
freely branched: the stems delicately filiform, 1-3 dm. long:
leaves filiform, about 1 mm. broad, mostly 3-6 cm. long but often
* In full fruit June 23 and the root leaves largely wanting.
144 BOTANICAL GAZETTE [AUGUST
longer: bracts, pedicels, and calyx glandular-pubescent: corolla
tube one-half longer to nearly twice as long as the calyx lobes.
The strongest character of the variety is its glandular inflorescence and its
longer corolla tube. Represented by NELSON and Macsripe’s no. 1192 from
Ketchum, July 19, 1911, found among the sagebrush on the river bottom lands.
Gilia Burleyana, n. sp.—Perennial from a completely lignified,
rather large root, with a more or less branched caudex, producing
few-many slender leafy suberect stems, 15-30 cm. high: pubescence
scanty, soft and crisped, more abundant on stems and inflorescence
than on the leaves: leaves alternate, small, numerous, entire, linear,
1-nerved, slightly thickened on the margins, mucronate-tipped,
1-4 cm. long: inflorescence capitate, or of 2 or more heads in a
terminal congested corymb: flowers numerous, small and very
crowded: calyx tube delicately scarious, twice as long as the green-
ish hirsute subulate mucronate lobes: corolla white, tubular, with
more or less reflexed lobes half as long as the tube; tube less than
5 mm. long, slightly exceeding the calyx, obscurely pubescent
within: anthers exserted; filaments inserted in the sinuses, shorter
than the corolla lobes: style about equalling the stamens: ovules
solitary in the cells, usually only one maturing and producing an
inequilaterally distended capsule: seed large, oblong, slightly
curved as is also the embryo, developing mucilage and spiracles
when wetted.
This rather extraordinarily strong species falls into the section ELAPHO-
cERA Nutt. as arranged by Dr. BRAND in his recent monograph. Until now
this section contained no perennials.
is species is named in honor of Mr. D. E. Burtey, general passenger
agent of the Oregon Short Line Railroad Company, whose cordial cooperation
and intelligent interest in scientific work is so greatly appreciated. The
type of the species is Netson and Macsripe’s no. 1126, from loose white
clay banks, a few miles from King Hill, Idaho, July 16, 1o1tr.
Cryptanthe scoparia, n. sp.—About 15 cm. high, fastigiately
branched from the base and upward, the erect branchlets broom-
like in their compactness: pubescence of a few stiff hispid spreading
hairs and a rather close layer of short white appressed ones: leaves
linear, the hispid hairs from pustulate bases: racemes numerous,
3-6 cm. long at maturity: fruiting calyces numerous and rather
crowded on the rachis: sepals very narrow, but thick, bluntly
1912] NELSON—IDAHO PLANTS 145
subulate, 4-5 mm. long in fruit: corolla not seen: nutlets 4, about
2 mm. long, narrowly conical, attached their whole length by an
open but narrow groove to a slender-subulate gynobase, the small
areola at base scarcely forked, closely muricate with silvery-gray
spinellae on a brown background.
Material in this genus is-assigned with difficulty. Floral characters give
but little clue. Aspect and the nutlets are the most reliable characters. Even
these seem to vary much, but after making due allowance for this fact, the
present specimens cannot be referred to C. multicaulis A. Nels., Bot. Gaz.
30:194, nor to C. grisea Greene, Pitt. 5:53, apparently the two nearest allies.
Both of these differ essentially as to the nutlets.
The type is NELSON and MAcBRIDE’s no. 1311, from sagebrush plains, near
Minidoka, July 24, ror.
PENTSTEMON CONFERTUS Dougl. —Perhaps in no group of
Pentstemon does a tendency to vary with every change in the
ecological conditions manifest itself so fully as in P. confertus and
its allies. In this group there are three rather strongly marked
species: P. attenuatus, P. confertus, and P. procerus, all by Douc-
LAS. In recent years several others have been added, some as
species and some merely as varieties. How many of these should
stand may not yet be said, but certainly not all of them. The
undue multiplication of species might be held measurably in check
if we could reach some agreement as to the relative importance of
the characters ordinarily relied upon in describing these plants.
The diagnostic characters mostly used are (1) pubescence in corolla
throat and on the sterile filament, (2) shape and size of the corolla
and the calyx lobes, (3) glandulosity of the inflorescence, (4)
pubescence on the herbage, (5) color of the corolla. Now it is
evident that if one phytographer considers one of these as of funda-
mental value in determining relationship, and another takes one
of the other characters as basic, and a third still another, and so on,
the number of species that may be described by the rearrangement
of these characters becomes merely a problem in permutation.
It seems, therefore, that one ought to place first those characters
which are probably modified the least by reason of a change of
environment, that is, those characters which are fundamentally
concerned with the perpetuation of the species should stand first
and the others should be serially arranged in the order in which they
146 BOTANICAL GAZETTE [AUGUST
relate themselves to this one great fact of reproduction. To illus-
trate: in this Pentstemon group the characters enumerated above
may well stand in the order given, for is it not probable that those
points of structure concerned with insect visitation come true
generation after generation, while such as viscosity, pubescence,
and color may change with every change of environment ?
How close are the three species enumerated may be seen in the
following facts: all have the sterile filament and the lower lip of
the corolla more or less bearded; all have the flowers in verticils
(two or more); all have calyx lobes more or less scarious-margined
and mostly more or less lacerate. If one undertakes to state cate-
gorically their differences, about all one can say even of supposedly
typical material is:
1. P. attenuatus.—Flowers yellow, rather large (20 mm. or more);
inflorescence glandular and pubescent.
2. P. confertus—Flowers yellow but small (less than 20 mm.
long); inflorescence pubescent or puberulent but not glandular.
3. P. procerus—Flowers not yellow (usually blue-purple),
small (less than 20 mm. long); inflorescence neither pubescent nor
glandular.
Of the three species, no. 2 seems most readily maintained as a
pure and fixed species. The scores of variants may rather satis-
factorily be grouped under 1 and 3. This being true, why not let
the large-flowered forms, having the other floral characters in
harmony, constitute the variety ?
P. attenuatus varians, n. var., without reference to color or the
presence or absence of pubescence or glandulosity.
Similarly let the small-flowered variants, having the other
floral characters of P. procerus, become P. procerus aberrans,
n. comb.
This varietal name was used by M. E. Jones as P. confertus aberrans, but
the specimens to which the name was applied are clearly of the P. procerus
group (see Proc. Cal. Acad. 2: 5-715).
I am fully aware that this disposition of this troublesome group means the
ieee of several pseudo-species, among which may be named P. micranthus
, P. Owenii and P. Rydbergii A. Nels., P. pseudoprocerus Rydb., and a
score hes or less) of Dr. GREENE’s species (see vol. I of Leaflets).
As excellent examples of P. attenuatus varians, I name MACBRIDE’S NO. 974,
1912] NELESON—IDAHO PLANTS 147
Twilight Gulch, Owyhee County, June 23, 1911, and his no. 1693, Pinehurst,
Boise County, August 17, rorr.
Pentstemon laxus, n. sp.—Minutely puberulent on stems and
foliage, the pedicels and calyx wholly glabrous: stems solitary or
few, from a compact mass of thick fibrous roots, slender and weak,
5-8 dm. high: leaves 6-9 pairs, not much reduced above, lanceolate-
linear, 5-10 cm. long: flowers in a crowded subcapitate terminal
cluster on a peduncle 6-12 cm. long and naked but for 1 or 2 pair
of linear approximate bracts; besides the terminal cluster there are
rarely produced from the axils of the upper leaves a pair of small
pedicellate clusters: calyx short, cleft to the base; its lobes broadly
obovate, obtuse, slightly erose, scarious with greenish center espe-
cially toward the tip, only 2-3 mm. long or about one-fifth as long
as the corolla: corolla a vivid blue, narrowly tubular and only
slightly dilated upward, 2-lipped, but the lips short, the longer
lower lip densely bearded with long yellow hair; the lobes all very
short, suborbicular: stamens glabrous, shorter than the corolla:
sterile filament shorter than the fertile, not dilated, blue at tip,
tapering and flexed at the very apex, glabrous or with 1-7 deciduous
airs.
This is probably not a very ‘strong species, but it seems fully as distinct
from any Pentstemon previously discussed as any two of them are from each
other. Further, if made merely a variety it would be difficult to say to which
one to unite it.
It was found on slopes in rich sagebrush lands. NeEtson and MAcsRIDE,
no. 1196, Ketchum, July ro, rort.
PENTSTEMON LINARIOIDES seorsus, n. var.—Very similar to
P. linarioides Gray (Bot. Mex. Bound. 112), from which it differs
primarily as follows:
Larger in every way, the rootstock notably woody: calyx green
and only half as long as the corolla; its lobes ovate, abruptly acute,
thick and green at tip, slightly scarious below: corolla glabrous in
the throat: the sterile filament longer than the fertile ones and
densely pubescent with short yellow hairs for its whole length.
At first it seemed impossible that these specimens from southwestern Idaho
should be referable to a species so long known only from southern Colorado,
New Mexico, and Arizona, and the above characters led to their being desig-
148 BOTANICAL GAZETTE [AUGUST
nated as a new species, P. seorsus. On further reflection it seems better,
however, to consider them as representing merely a variety.
Collected by MacsrinE at Twilight Gulch, Owyhee County, in lava fields,
June 22, IgII, no. 970.
PENTSTEMON ERIANTHERA Whitedii, n. comb.—P. Whitedii
Piper, Bot. GAZ. 22:490. Igot.
Mr. Piper, in Contrib. Nat. Herb. 11: 500, reduces his species to a synonym
of P. erianthera Pursh, but this was hardly justified. P. erianthera Whitedii is
of different habit, producing several stems (instead of only 1 or 2) from a wood
taproot; the stems are more slender; the leaves narrower and more numerous;
the glandular-pubescence throughout is less pronounced; the sepals are lanceo-
late, acute (not acuminate); the corolla is light blue without any of the peculiar
red found in typical P. erianthera. While the pubescence in the throat and on
the sterile filament is of the same character, it is far less copious. For these
reasons it seems that the northwest forms may well be abieie: as a variety of
the typical Rocky Mountain P. erianthera.
NELSON and MAcBRIDE’s no. 1421, secured at Mackay, on gravelly sage-
brush slopes, July 30, 1911, is typical of the variety.
CASTILLEJA VISCIA Rydb.
The range of this excellent species is greatly extended by MACBRIDE’s no.
990 from Silver City, Owyhee County. While Macsripe’s plants are not quite
typical, yet they help to a better understanding of the species. These are more
densely glandular and lack the crimson or scarlet tips in bracts and corolla.
The corolla is of the right proportions, but smaller.
Castilleja multisecta, n. sp.—Freely branched from a woody
caudex, the ascending stems sparingly branched, 2-4 dm. high,
including the long fruiting spike which is often more than one-
third of the plant: pubescence inconspicuous, very softly lanate
throughout: leaves 2-4 cm. long, numerous, pinnately parted into
5-7 narrowly linear lobes, the lateral ones sometimes again parted,
the undivided base obcuneate and strongly 3-nerved: bracts
resembling the leaves but the segments tipped with red, as are also
the margins of the galea: calyx more deeply parted above than
below, the primary lobes deeply toothed, the thin triangular teeth
acute: corolla slender, about 3 cm. long; the galea being about
one-third of this; the lower lip very short, saccate, its short broad
truncate teeth with a central cusp: seeds beautifully honey-
combed on the surface with shallow scarious cell walls.
1912] NELSON—IDAHO PLANTS 149
In spite of the large number of species of Castilleja of somewhat similar
aspects and with dissected leaves, I do not seem to be able to refer this to any
near ally. The type number is NELSON and MAcsriDE’s 1261, secured on
disintegrated granite slopes at Ketchum, Blaine County, Idaho, July 21, ro11.
MISCELLANEOUS SPECIES
Eriogonum loganum, n. sp.—Perennial with woody branched
caudex, the current year’s stems short, simple, leafy, densely
white-lanate as are also the leaves, peduncles, and involucres,
assurgent, 1 dm. or less long and terminating in a stout ascending
scapelike peduncle 12-25 cm. high: leaves oblanceolate, mostly
narrowly so, obtuse or subacute, very white and densely appressed
lanate, 2-3 cm. long, on pedicels of about the same length: invo-
lucres tubular-campanulate, thin and scarious between the 5 or
6 nerves, 4-5 mm. long, many-flowered: perianth glabrous, pale
(greenish-white), directly articulated to the capitate apex of the
slightly exserted pedicels; perianth segments thin but with a stout
rounded midrib raised on the inside, the outer and inner similar,
oblong, obtuse, about 2 mm. long: achene glabrous, 3 mm. long,
the ovoid-triangular body not longer than the tapering beak.
This description has been drawn from specimens supplied by CHARLES
Piper Smitu, of Logan, Utah, under no. 1704. It occurs on the dry bench
lands or terraces near the college, and is in blossom late in June, with ripe
achenes in July. These specimens have been referred to E. ochrocephalum
Wats., but that species seems quite distinct from this.
LESQUERELLA LUNELLII lutea, n. var.—Much like the species,
seemingly blossoming even the first year from seed, hence some
specimens appear as annuals, some as biennials, and still others as
perennials, with slender woody taproot: leaves narrowly oblanceo-
late: flowers yellow, a little larger than in the species.
This variety is probably only an ecological variation. Dr. LUNELL has
now secured the species itself from several localities in Benson County, and
these sustain the characters as originally given, including the purple blade of
the petals. The variety he has secured in three other counties (Ward, Mc-
Henry, and Rolette), and it differs primarily in that the petals are yellow, as
one expects them to be in this genus. It would no doubt have been more in
harmony with our conception of the genus had the form with yellow petals been
discovered and named first, the purple one becoming the variety.
150 BOTANICAL GAZETTE {AUGUST
Astragalus Batesii, n. sp.—Stems few to several, spreading from
the summit of a slender woody taproot, only 1-4 cm. long, very
leafy; leaves pinnate, 5-9 cm. long including the slender petiole;
leaflets mostly 7-11, narrowly oblong, obtuse, strigose-canescent,
greenish and becoming glabrate above: flowers in terminal, capitate,
few-several-flowered racemes on very slender peduncles which in
fruit equal or exceed the leaves; bracts lance-linear, silky, shorter
than the silky calyx: calyx lobes linear, as long as the tube: corolla
pale violet, 6-8 mm. long, exceeding the calyx, turning somewhat
yellowish with age: pod strictly 1-celled, with straight keel except
the tip, narrowly oblong, tapering to the acuminate or cuspidate
tip, with short silky appressed pubescence, 12-15 mm. long, when
mature lightly transverse rugose.
Rev. J. M. Bates, of Red Cloud, Neb., for many years a careful student
of his local flora, contributes the fine specimens upon which this description
is based. Having carefully studied the plant in the field and being familiar
with the species of Astragalus of his range, he submitted this as probably
different from any of the described species. In this opinion I must concur, and
I therefore take this opportunity to dedicate the species to its discoverer. The
species is most nearly allied to A. Jotiflorus Hook. from which it is at once
distinguished by its more appressed pubescence, its violet flowers, and its
strictly 1-celled pod in which the dorsal suture is not at all impressed. The
type is deposited in the Rocky Mountain Herbarium under the collector’s no.
5501, Red Cloud, Neb., May 17 and May 23, 1911. A splendidly fruited speci-
men secured at the same place, June 9, 19090, in also deposited with the type.
Mertensia campanulata, n. sp.—Glabrous throughout, even
to the calyx lobes: root thick and semi-fleshy, giving rise to few
or solitary erect stems: stems moderately leafy, pale below:
root leaves oblong, tapering to both ends, obtusish at apex, cuneate
at base, the blade 8-12 cm. long, on petioles usually longer than
the blade: stem leaves oblanceolate, tapering to a margined base, the
middle ones the largest but these smaller than the root leaves, the
uppermost very much reduced: panicle rather small and open,
short-peduncled, 1-3 slender accessory peduncles from the upper-
most leaves: calyx campanulate, about 5 mm. long, the broadly
triangular obtusish lobes not more than one-fourth as long as the
tube: corolla deep blue, beautifully veined with brown, 18-20 mm.
long, tubular, the tube proper about half of it; the relatively long
Igr2] NELSON—IDAHO PLANTS ISI
throat but slightly dilated; the short lobes (3-4 mm.) abruptly
reniformly expanded: anthers linear-oblong; filament inserted at
the summit of the tube proper, as broad as the anther but only half
as long, the two together as long as the throat: nutlets smooth or
nearly so.
This seems to be an unusually strong species. Carelessly examined it
migltt be referred to M. ciliata, but in reality it is closer to M. Macdougallii
Rydb., of Arizona, from which it is clearly distinct and is equally distinct from
M. Leonardi Rydb. Its calyx is distinctive in this genus.
Mr. C. N. Woops, supervisor of the Sawtooth National Forest, secured it
“in moderately moist meadows” and sent in the ample specimens, at the same
time calling attention to its salient characters. No. 325, Blaine County,
Idaho, tort.
UNIVERSITY oF WYOMING
LARAMIE, WYOMING
BENEFICIAL EFFECT OF CREATININE AND CREATINE
to lS EINN ER
(WITH ONE FIGURE)
This paper embodies a series of experiments on the influence of
creatinine and creatine on seedling wheat. These experiments
were made in an endeavor to throw light on the action of organic
manures in soils, and the influence of soil organic matter on pro-
ductivity. Creatinine has been discovered as a soil constituent in
this laboratory by Dr. E. C. SHorEy,? and an account of its occur-
rence and properties will be given elsewhere. This nitrogenous
constituent occurs plentifully in animal products, wine, meat, etc.,
but has recently been found in these laboratories by Dr. M. X.
SULLIVAN; to be a constituent part of many plants and seeds,
and to occur in the medium in which plants have grown. The
general methods for studying the effect of creatinine on plants in
solution cultures is the same as that employed in connection with
the harmful soil constituent, dihydroxystearic acid, previously
reported in this journal.
Effect of creatinine on growth
Two sets of cultures, composed of the fertilizer salts calcium acid
phosphate, sodium nitrate, and potassium sulphate in varying pro-
portions, used singly and in combinations of two and three, were
prepared, the proportions varying in 10 per cent stages, thus mak-
ing a total of 66 culture solutions according to the plan in the
* Published by permission of the Secretary of Agriculture, from the Laboratory
of Soil Fertility Investigations.
2 SHoREY, Epmunp C., The isolation of creatinine from soils. Jour. Amer.
Chem. Soc. 34:99. 1912.
3 Surtivan, M. X., The origin of creatinine in soils. Jour. Amer. Chem.
Soc. 3322035. tori.
+ SCHREINER, O., and SKINNER, J. J., Some effects of a harmful organic soil con-
stituent. Bot. Gaz. 50: 161. 1910; Ratio of phosphate, nitrate, and potassium on
absorption and growth. Bor. GAz. 50:1. 1910,
Botanical Gazette, vol. 54] [152
Ig12] SKINNER—CREATININE AND CREATINE 153
papers cited. Young wheat seedlings were grown in this series of
solutions from March 3 to March 15. To one set of the 66 cultures
only the nutrient salts were added, to the second set 50 ppm. of
creatinine were added to each culture. Every three days the
solutions were changed and analyzed.
When the two sets of cultures had grown for several days, it
was noticeable that the creatinine plants were better developed,
having broader leaves and longer and well developed roots. This
was more noticeable in some of the fertilizer mixtures than in others.
The total growth made in the 66 cultures of nutrient salts with-
out creatinine, designated as normal cultures, was 166.7 grams as
against 181.2 grams in the case of the 66 cultures with 50 ppm. of
creatinine. Putting the normal at 100, the latter becomes 109, or
an increase of 9 per cent as an average of the 66 cultures. As
already mentioned, the effect was much more pronounced in cer-
tain fertilizer combinations, especially those containing no nitrates,
or those low in nitrates. The effects of creatinine in these cultures
will now be considered in detail.
Effect of creatinine on growth in cultures containing no nitrate
Table I gives the growth of two sets of cultures composed of
mixtures of phosphate and potash, varying in ro per cent =
TABLE I
SHOWING THE EFFECT OF CREATININE ON GROWTH IN CULTURES CONTAINING NO
NITRATES ,
PPM. OF FERTILIZER INGREDIENT IN CULTURE GREEN WEIGHT OF CULTURE
SOLUTION IN GRAMS
No.
P.0, NE, K.0 creatinine | cruptiahib
Eo ° ° 80 1.400 1.576
ee rye, Serra 8. ° 72 1.470 2.200
Siac 16 fo) 64 1.950 2.100
ene 24 fo) 56 1.527 2.000
Sree a2 ° 48 1.490 2.200
Ort os 40 ° 40 1.558 2.408
(SO eee 48 ° 32 1.795 2.328
Si 56 fe) 24 1.540 2.400
ee eae 64 ° 16 1.444 2.220
TO a a 72 ° 8 1.400 2.100
1G a 80 fe) ° 1,100 1.150
Sten
154 BOTANICAL GAZETTE [AUGUST
there being no nitrate in the solutions; the concentration was
80 ppm. of P,O,+K,0 in each culture. To one set of cultures was
added 50 ppm. of creatinine. In the fifth column are given the
green weights of the cultures without creatinine, and in the last
column are given the weights of the cultures with creatinine. It
is apparent from these figures that the creatinine has caused a
Fic. 1.—Wheat plants growing in culture solutions containing various propor-
tions of potash and phosphate (with no nitrates) without (a) and with (6) creatinine.
considerable increase in growth. This is true in each of the 11
cultures. The total growth of the eleven cultures, without
creatinine, was 16.674 grams against 22.682 grams for the
cultures with creatinine. This is an increase of 36 per cent in
the creatinine cultures.
The effect of creatinine in cultures with no nitrogen are shown
in the plants in fig. 1. Cultures marked with the same number,
for instance 1a and 16, have similar fertilizer ratios. The cultures
marked a have no creatinine, the numbers with the letter ) have
1912] SKINNER—CREATININE AND CREATINE 155
50 ppm. of creatinine. As shown in the photograph, the plants in
each culture containing creatinine, regardless of the proportion of
potash and phosphate, is larger than the plants grown in a similar
solution without the creatinine. The increased growth is notice-
able in the roots as well as the tops. The tops in each case are
broader and taller, the roots are larger and better branched.
Effect of creatinine in cultures containing 8 ppm. NH, as nitrate
Since creatinine was very beneficial in cultures containing no
nitrate, it is interesting to observe its effect in cultures which con-
tain a small amount of nitrate. Table II gives the result of the
TABLE II
SHOWING THE EFFECT OF CREATININE ON GROWTH IN CULTURE SOLUTIONS COMPOSED
F FERTILIZER MIXTURES, CONTAINING 8 PPM. OF NH, AS NITRATE
PPM. OF FERTILIZER INGREDIENTS IN CULTURE GREEN WEIGHT pak CULTURE
SOLUTION IN GRAM
No.
P.Os NH; K.0 eudaian Pai
Saar ara ° 8 72 1.820 2.190
Be 8 8 64 2.470 3.100
Oe eee 16 8 56 2.748 3.250
foe eae 24 8 48 2.9007 3.420
sa rarie Sat 32 8 40 2.670 2.450
OSS: 40 8 32 2.928 3.258
et re 48 8 24 2.526 3.340
Be ee 56 8 16 2 3.000
See eee 64 8 8 2.048 2.359
TO bee cey as 72 8 ° 1.354 1.750
effect of creatinine on growth in culture solutions composed of
8 ppm. of NH, as nitrate, and varying amounts of phosphate and
potash, the total concentration of each solution being 80 ppm. of
P,O;+NH,+K.,0. By comparing the figures it is seen that the
growth with creatinine, given in the last column, is larger than the
growth without creatinine, given in the fifth column. The differ-
ence, however, is not nearly so large as in solutions containing no
nitrate, presented in table I. The total green weight of the cultures
composed of fertilizer mixtures containing 8 ppm. of nitrogen with-
out creatinine was 24.071 grams against 28.117 grams in the cul-
156 BOTANICAL GAZETTE [AUGUST
tures with creatinine, an increase of 17 per cent. In the cultures
with no nitrate creatinine produced an increase of 36 per cent.
Effect of creatinine in cultures with larger amounts of nitrate
It has been shown that creatinine was very beneficial in cultures
which contained no nitrates. In a group of cultures, composed of
mixtures of phosphate and potash in different proportions, creatinine
increased the growth 36 per cent. It has also been pointed out
that the beneficial effect of creatinine was not so great in cultures
containing a small amount of nitrate. In a second group of
cultures, composed of mixtures of potash, phosphate, and 8 ppm.
of NH, as nitrate, creatinine increased the growth only 17 per cent.
In table III are given the results of growth in cultures with and
without creatinine, composed of mixtures of phosphate, potash,
and nitrogen having 16ppm. NH, as nitrate. The green weights
of the creatinine cultures given in the last column of the table are
slightly larger than the normal cultures, as shown in the fifth
column. The total green weight of the cultures without creatinine
was 25.516 grams against 27.573 grams for the cultures with
creatinine, an increase of 8 per cent.
TABLE III
SHOWING THE EFFECT OF CREATININE IN CULTURES CONTAINING 16 ppM. OF NH;
AS NITRATE
PPM. OF FERTILIZER INGREDIENTS IN CULTURE GREEN WEIGHT OF CULTURES
SOLUTION IN GRAMS
No.
P.0s NH, K.0 or cont
Sea 8 ° 16 64 2.200 2.579
Fons cunts 8 16 56 3.200 3-720
a a aes! 16 16 48 3.500 3-500
Cos 24 16 40 3-007 3-792
5 as 16 32 3.250 3-259
Cie apace 40 16 24 3.228 3.390
Fe oS ep ais a 48 16 16 2.975 3.240
Sica ee 56 16 8 2.626 2.551
Oi fore wes. 64 16 ° 1.440 1.749
In other cultures composed of the three fertilizer ingredients
P,0,, NH,, and K,O, but containing 24 ppm. of NH, as nitrate,
creatinine increased growth only 2 per cent. Its effect in cultures
1gt2] SKINNER—CREATININE AND CREATINE 157
composed of fertilizer mixtures having more than 24ppm. of
nitrate was uncertain; in some cases there was a slight increase in
growth and in others there was a slight decrease, that is, the growth
with these higher amounts of nitrate in the solution was practically
the same in the normal and creatinine cultures.
Before discussing further the effect of creatinine, it will be
necessary to recall the effect which nitrates have on the growth of
plants in mixtures of the other two fertilizer ingredients potash and
phosphate. In work previously published,’ it was shown that the
better growth occurred in the normal cultures when the three fer-
tilizer elements P,O,, NH;, and K.O were present. It was best in
mixtures which contained approximately equal amounts of NH,
and K,O and a small amount of P,O, (about 16ppm.). The
growth in the cultures containing the three constituents was much
greater than in the cultures containing only two constituents.
This was especially marked when nitrogen was not in the compo-
sition. In illustration of this, the average growth of a number of
cultures, composed of mixtures of phosphate and potash in amounts
of 80ppm. of P,O,+K.,0, was 1.000 gram against 3.155 grams as
the average growth of cultures composed of mixtures of these two
ingredients, with an addition of only 8 ppm. of NH, as nitrate, the
total concentration of nutrients being the same. In a second
experiment conducted in a similar manner, but at a later date, the
average growth of the cultures, composed of mixtures of phosphate
and potash, was 0.878 gram, and the average growth of cultures,
in mixtures of the three ingredients, containing 8 ppm. of NH, as
nitrate, was 2.107 grams.
n the present experiment the growth in the normal cultures —
composed of varying proportions of phosphate and potash, com-
pared with the growth in mixtures of these two ingredients, with
8 ppm. of NH, as nitrate added, is given in table IV. By a close
examination of the figures in this table, it is seen that the growth
in the mixtures of phosphate and potash is smaller than in cultures
composed of mixtures of the three ingredients, though containing
5 SCHREINER, O., and SKINNER, J. J., Ratio of phosphate, nitrate, and potassium
on absorption and growth. Bor. Gaz.50:1.1910. Some effects of a harmful organic
soil constituent. Bull. 70, Bureau of Soils, U.S. Dept. Agric. rgro.
158 BOTANICAL GAZETTE [AUGUST
but 8ppm. of NH,. The average growth of the cultures without
nitrogen is 1.516 grams against 2.407 grams with 8 ppm. of NH;
in the fertilizer mixture. Putting the growth of the cultures with-
out nitrogen at 100, the relative growth of the cultures with nitrogen
becomes 159, or an increase of 59 per cent.
TABLE IV
SHOWING THE GROWTH OF CULTURES, COMPOSED OF FERTILIZER MIXTURES CONTAINING
NO NITRATE, AND 8 ppm. OF NH; AS NITRATE, WITHOUT AND WITH CREATININE
a a ne aes GREEN WEIGHT OF CULTURES IN GRAMS
ane Without creatinine With creatinine
P.O; NH; K.0
No nitrate | 8 ppm. NH;/ No nitrate | 8 ppm. NH;
Toor fo) ° 80 1 feo aires Cetera T.570 Lee
Po ° 8 Fo ee ane ete £8205 5G oe 2.190
fee les 8 ° 72 ane Trois Mego 2.200 Abo ea
Mie ce es 8 8 be 1. SATO ae, 3.100
Bee eh. 16 ° 64 £OS00 1 Ga BOO OV es ce
Deere, 16 Bo Oe CSE Se ee 3.250
Fees 24 ° 56 $5275 | Sess z.GOO jes
Ee ee 24 8 Be ee, O07 bet: 3.420
1 ae ge 32 fo) 48 EeADO bee, @,900) forse
LL eecnewe 32 8 A Pp 9.670 Po Geeis 2.459
ot. 40 fe) 40 8 ge 3.408 fb a50e,
ES eee 40 8 i gees, ys ne ee) ae We ea Ce 3.258
bs ea 48 ° 32 T9082 fs 22965 fees
sO ae eae: 48 8 pt as ae Sepa S20 te 3.340
Peo Se. 56 ° 24 £540.) es 2°400 | sea
> Gee 56 8 EO ei ee 2.000. 2) ngs ss 3.000
EP: 64 ° 16 PARA oe 9.2201 eras
BES, 64 8 Se DAB ol ee 2.359
1G. 72 ° 8 E400 1 Oey Dees .4 eed Cae
yo ee 72 8 eee ee 1.554 | <--> 1.759
255 4 80 ° ° PIOO es ce L550. we
With soppm. of creatinine in the solution, the. cultures con-
taining no nitrogen produced better growth than the corresponding
cultures without creatinine, as shown in the last two columns of
table IV. The difference between the last two columns is not as
marked in the creatinine set as in the corresponding columns for the
normal set. The average growth of the creatinine cultures without
nitrate is 2.062 grams against 2.812 grams for the cultures having
8 ppm. of NH; as nitrate in the fertilizer mixture. If the growth
of the cultures without nitrate is put at roo, the growth with 8 ppm.
1912] SKINNER—CREATININE AND CREATINE 159
of NH; in the fertilizer mixture becomes 136, or an increase of only
36 per cent.. In other words, in the absence of creatinine from the
cultures, the nitrate (8 ppm.) caused an average increase of 59 per
cent in the various cultures; in the presence of the creatinine
(50 ppm.) the nitrate (8 ppm.) caused an average increase of only
36 per cent. It appears, therefore, that plants supplied with
creatinine do not respond so markedly to added nitrate, thus seem-
ing to indicate that the plant can utilize this nitrogenous compound
for plant syntheses.
Effect of creatinine on absorption of fertilizer salts
The foregoing discussion has shown clearly the influence of
creatinine on growth and its effect in cultures containing no nitrates.
There remains to be discussed the effect of the creatinine on the
removal of nutrients from the solution during the growth of
the plant.
Mention has been made already of the fact that the concentra-
tion differences produced by the growth of the plants in the various
cultures were determined by making an analysis for nitrates at the
termination of every three-day change, and of the phosphates and
potassium on a composite of the solutions from the four changes.
It is thus possible to compare the results obtained under the so-
called normal conditions without the creatinine and under the
conditions where 50 ppm. of creatinine were present in the solution.
The sum total of P,O,, NH,;, and K,0 removed from solution by
the growing plants in the cultures containing all three of these
constituents was 1684 milligrams under the normal conditions, and
1584 milligrams in the creatinine set. The figures show the total
of plant nutrients to be slightly less in the creatinine set, although
the green weight in this set was g per cent greater than in the normal
set. The examination of the results for the three constituents
separately as given below shows that the phosphate and potash were
slightly greater than normal, as is demanded by the larger growth,
whereas the nitrate is considerably less than in the normal set.
Phosphate-—The amount of phosphate stated as P,O, removed
from the total number of solutions during the experiment was 364
milligrams for the normal cultures and 383 milligrams for the cul-
160 BOTANICAL GAZETTE [AUGUST
tures containing creatinine, a difference of 19 milligrams in favor
of the creatinine cultures.
Potassium.—The amount of potash stated as K,0 removed by
the plants in the total number of cultures was 760 milligrams in
the case of the normal cultures and 778 milligrams for the cultures
with creatinine. As with the phosphate, the creatinine cultures
removed a little more potash than the normal cultures, there being
a difference of 18 milligrams in favor of the creatinine set.
Nitrogen.—The total amount of nitrogen stated as NH, removed
from the total number of solutions during the course of the experi-
ment was 560 milligrams for the normal cultures and 423 milligrams
for the creatinine cultures. The creatinine cultures though making
a larger growth used 137 milligrams less nitrate.
Effect of creatine on growth
Creatine is closely related chemically to creatinine, the latter
being the anhydride of creatine. Both probably occur in soils,
. manures, and green crops, a discussion of which is given in the two
other papers referred to. Experiments in nutrient cultures with
creatine have been conducted similar to those with creatinine.
The plants grew from April 22 to May 4. After the plants had
grown for several days, it was apparent that the effect of creatine
was very similar to that of creatinine. The leaves were broader,
and further developed than those of the normal culture. The roots
were longer and better branched. The plants growing in cultures
with creatine, which contained phosphate and potash but no nitrate,
were a great deal larger than similar cultures without creatine.
Like the creatinine, when small amounts of nitrate were in the fer-
tilizer mixture, the beneficial effect of creatine was not so marked,
and in the presence of larger amounts of nitrate creatine had no
additional effects.
The total green weight of 66 cultures containing the fertilizer
salts only, that is the normal set, was 174.4 grams, against 186.8
grams for the 66 cultures containing 50 ppm. of creatine in addition
to the fertilizer salts. This is an increase for the creatine cultures
of 8 per cent over the normal cultures. _
Table V shows the effect of creatine on growth in a number of
Igt2] SKINNER—CREATININE AND CREATINE 161
cultures containing varying amounts of phosphate and potash, but
no nitrates, the amount of total fertilizer ingredient in each culture
being 80ppm. By an examination of the table it is apparent that
the growth of each of the creatine cultures given in the last column is
considerably larger than the growth of the cultures without creatine
given in the fifth column. The total green weight of the cultures
without creatine was 16.2 grams against 23.3 grams for the cul-
tures with creatine, an increase of 44 per cent.
TABLE V
SHOWING THE EFFECT OF CREATINE ON GROWTH IN CULTURES CONTAINING NO NITRATE
PPM. OF FERTILIZER INGREDIENT IN CULTURE GREEN WEIGHT OF CULTURES
OLUTION IN GRAMS
No.
Without With
P.Os NH K:0 creatine creatine
Besa ° ° 80 1.329 1.709
Ye er et ito 8 ° 72 I.420 1.948
pie oe VEG 16 ° 64 1.558 2.130
BEST es 24 ° 56 1.579 2.370
ie Pen gees 32 ° 48 1.528 2.470
2 ep Cte PO LEse 40 ° 40 1.500 2.400
Regie Pes alt 48 oY 32 1.670 2.270
SiN 56 ° 24 1.628 2.420
See nee 64 ° 16 . 2.450
EO eee ra 72 fe) 8 1.428 2.070
bo ea ata ah 80 ° ° 0.978 I.090
In table VI are given the green weights of plants grown in
cultures with and without creatine, containing 8ppm. of NH,
as nitrate and varying amounts of P.O; and K,O, the total
constituents being 80ppm. of P.O;+NH;+K.0. These figures
show that the creatine cultures given in the last column are
somewhat larger than the cultures without treatine given in
the fifth column, but the difference is not nearly so large as
in the cultures containing no nitrate given in table V. The total
growth of the cultures without creatine was 26.4 grams against
29.4 grams for the cultures with creatine, an increase of only
II per cent in favor of the creatine cultures. There was a
difference of 44 per cent in favor of the creatine cultures in the
case of the solution which contained no nitrate.
162 BOTANICAL GAZETTE [AUGUST
The growth in the cultures which contained varying amounts
of phosphate and potash and 16 ppm. of nitrate was only 3 per cent
greater with than without creatine. In solutions containing
24ppm. of nitrate the increased growth with creatine was 6 per
cent, and in solutions containing 32 ppm. nitrate the increased
growth 4 per cent. In solutions containing higher amounts of
nitrate the creatine had no additional effect. Thus it appears that
the effect of creatine in replacing the effect of nitrate in producing
growth is very similar to that of creatinine.
TABLE VI
SHOWING THE EFFECT OF CREATINE ON GROWTH IN CULTURES CONTAINING 8 PPM. OF
NH; AS NITRATE
PPM. OF FERTILIZER INGREDIENT IN CULTURE GREEN WEIGHT OF CULTURES
SOLUTION IN GRAMS
No.
P.O, NH K.0 phere ae
2 ne ° é 72 2.299 2.4590
ois ees 8 ‘ 64 2.940 3.200
Sas 16 3 56 2.700 3-350
Bac so Sa 24 } 48 2.920 3-400
Sakic ea ve 32 } 40 3.050 3-979
Ores. 40 } a2 3.150 3-309
5 EEE 48 24 3.220 3-359
Sila cee es 56 16 2.5 2.854
ee EA see 64 ; 8 2.222 2.800
1... oS 72 ro) 1.400 1.600
It is also interesting to note the effect of creatine on the removal
of salts by the plants and the similarity between the action of
creatine and creatinine in this respect. It will be remembered that
in the creatinine cultures the removal of phosphate and potash was
slightly greater in the creatinine cultures than the normal cultures,
but a great deal less nitrate disappeared from solution in the
creatinine than in the normal cultures.
In the creatine experiments the removal of total P,O,, NH;, and
K,0 by plants in the normal cultures was 1978.3 milligrams,
against 1854.5 milligrams for the creatine cultures. ‘The normal
cultures removed 471.0 milligrams of P,O,; and the creatine cul-
tures 474.4 milligrams. In the case of potash the normal cultures
Igt2] SKINNER—CREATININE AND CREATINE 163
removed 769.4 milligrams of K,O against 767.4 milligrams for the
creatine cultures. The removal of both phosphate and potash was
practically the same in the normal and creatine cultures. The
disappearance of nitrate was much less in the creatine than in the
normal cultures. The normal cultures removed 737.7 milligrams
against 612.7 milligrams for the creatine cultures, a difference of
125 milligrams.
The influence of the creatine in regard to the removal of P.O,,
NH,, and K,0O is very similar to that shown by creatinine, and it
again appears that this substance as well as the creatinine can
replace nitrates in its effect on plant growth.
Bureau or Sorts, U.S. DEPARTMENT OF AGRICULTURE
WASHINGTON, D.C.
BRICPERM ARTICLES = =
A NOTE ON THE GENERATIONS OF POLYSIPHONIA:?
(WITH ONE FIGURE)
YAMANOUCH?? concludes from his cytological work on Polysiphonia
violacea that “there is an alternation of a sexual plant (gametophyte) and
an asexual plant (sporophyte) in the life history of Polysiphonia, the
cystocarp being included as an early part of the sporophytic phase.”
He found that on the cystocarpic plants there was an occasional ab-
normality “in the form of a cell resembling a monospore, but having
the same cell lineage as the tetraspore mother cell.’ He traced the
development of these cells and found that although cleavage furrows
appeared, the nucleus rarely entered a mitosis and the cell never divided.
He makes note of the fact that Lotsy has found tetraspores on the same
plants with sexual organs in Chylocladia kaliformis and that Davis has
found the same condition in Spermatothamnion Turneri, Ceramium
rubrum, and Callithamnion Baileyi. He suggests that possibly the
structures reported as tetraspores are really monospores and are de-
veloped with a suppression of reduction phenomena, or that the sexual
organs are developed apogamously.
Lewis’ has attempted an experimental test of the truth of YAMA-
Noucui’s conclusion. He says: “Cytological observations on Poly-
siphonia by YAMANOUCHI, on Griffithsia by myself, and on Delesseria
by SvEDELIus render it probable that in these genera at least, and pre-
sumably in all Florideae in which tetraspores and sexual organs are borne
on separate individuals, there exists an alternation of sexual and asexual
plants, the carpospores giving rise on germination to asexual, and the
tetraspores to sexual individuals.” The results that he obtained by
growing plants from the spores of Polysiphonia violacea, Griffithsia
Bornetiana, and Dasya elegans are consistent with the above theory, no
carpospores having been found to produce sexual individuals, and no
tetraspores to produce asexual individuals. Both the cytological and
the experimental evidence would thus seem to unite in indicating that
* Contributions from the Puget Sound Marine Station, no. 2.
? YaMANoucuI, S., The life history of Polysiphonia. Bot. Gaz. 42:401-449-
1906.
3 Lewts, I. F., Alternation of g ions in certain Florideae. Bor. Gaz. 53:239-
242. IQI2.
Botanical Gazette, vol. 54] [164
1912] oe BRIEFER ARTICLES 165
there is an alternation of generations in at least Polysiphonia violacea,
and to offer at least some foundation for the belief that it is general
among the red algae.
In 1911 Professor T. C. Frye found in Polysiphonia material, col-
lected at the Puget Sound Marine Station in 1910, some specimens
showing both carpospores and tetra-
spores on the same individual. This
observation was made in the course
of laboratory work with a class and
no material was kept. He suggested
to the senior author of this note
that the subject be investigated
further at the Puget Sound Marine
Station. The junior author ex-
‘amined the Polysiphonia material
that was brought into the labora-
tory at the station during the ses-
sion of 1911. In one lot of material
she found the same condition to
which Professor Frye had referred.
The material was collected in the
lower littoral zone on the rocky shore
of Turn Island, near Friday Harbor,
Washington. It has been identified
by Professor W. A. SETCHELL of the Fic. 1.—Camera lucida drawing of
University of California as Pterosi- * sees abe re soca acaepegse
the same individual both
phonia bipinnata and by Dr. SuH1cko suede and a cystocarp with a
YaMANoucHI of the University of carpospore.
Chicago as Polysiphonia sp.
The fact that the mother cells had gone to the point of complete
division into tetraspores in the material examined indicates that the
tetraspores were not abortive, and the fact that carpospores were seen
issuing from cystocarpic plants that bore also perfect tetraspores indi-
cates that the cystocarps were not abortive. We have thus an indi-
vidual that is both sexual and asexual, which is inconsistent with there
always being in this species an alternation of a sexual individual and an
asexual.
Professor T. C. Frye and the senior author of this note are now at
work on the cytology of specimens of this species with a view to determin-
ing the sporophytic or gametophytic nature of this generation by means
of mitotic studies—GrorcE B. Rice and Annrz D. Datetry.
CURKENT LITERATURE
BOOK REVIEWS
Forest physiography'
This volume, intended primarily for the use of foresters, will be of very
eat value to ecologists, even to those working upon problems which are
unrelated to forests. Its field of a a farther still, for it is the
rst work in which the much-scattered lit re dealing with the physiography
of various parts of the United States has been summarized and systematized.
It will thus be frequently consulted by geologists, geographers, economists,
and travelers. The ecologist as a rule must work out for himself the physio-
graphic processes which are in immediate operation in his field of study. The
value of Professor BowMaAn’s work will be found to lie principally along two
lines: in the clearing up of the physiographic history of the region, and in
comparison of the field of study with other parts of its physiographic region
and with other regions.
The book comprises two parts. Part I is entitled ‘The soil,” and is a
summary of the present knowledge of that subject as it pertains to forest
growth. This section is included because the influence of the physiographic
processes upon forests is exerted largely through the formation, modification,
and destruction of soils. It seems to the present writer that a better plan
would have been to expand this section into a separate work, since the two
parts of the book are essentially independent. The topics treated are as
follows: importance, origin, and diversity of soils; physical features; water
supply; temperature; aesiieas features; humus and nitrogen supply; soils
of arid regions; soil classification.
In part II the physiography of the United States is considered by regions,
each subdivision having “an essential uniformity or unity of geologic and
physiographic conditions,’ and therefore a uniform topographic expression
in the main. The sequence is from west to east. An introductory chapter
discusses physiographic, climatic, and forest regions. In consideration of
climate, full recognition is given to the combined effect of the various factors
upon plant distribution, and yet MErR1am’s “life zones” are accepted, although
they are based upon temperature alone.
The chapters devoted to the various physiographic regions are largely
descriptive of the present topography, with only such geologic details as are
necessary to explain it. As the author remarks in the preface, the forester
* BowMAN, Isarau, Forest diet pp. xxiit+759. pls. 6. figs. 292. New
York: John Wiley & Son, torr
166
1912] CURRENT LITERATURE 167
is concerned with the relief of a region rather than with its geologic history.
At the same time, the historical treatment is entirely adequate to satisfy,the
needs of an ecologist, and abundant references to the literature are given for
the benefit of any who wish more detailed information. To illustrate the
mode of treatment, the section devoted to the Adirondack Mountains may
be cited. The subdivisions are as follows: geologic structure, topography
and drainage, glacial effects, climate and forests.
The notes upon the forests which are appended to most of the sections
are the least satisfactory portions of the work, being so brief and general as
to be almost useless, and in one case at least inaccurate. The conifer forest
of the southern Appalachian summits is referred to in three places. p. 122
it is correctly described as “spruce and balsam.” On p. 125 we read of the
“spruce and hemlock forests on the summits of the Pisgah and other ranges
in western North Carolina, where boreal conditions exist.”” The hemlock
in these mountains is found principally in deep ravines in the lower hardwood
forest belt, and rarely attains to the lower margin of the spruce-balsam forest.
p. 614 occurs the statement that ‘‘on the higher summits of the Great
Smoky, Pisgah, and Balsam Mountains are a few thousand acres of black
- On the
belongs, in “shaded ravines and on the better watered northern or north-
western slopes between 3000 and 5000 feet.”
The book is adequately illustrated and has valuable physiographic and
geologic maps. Its great weight is to be regretted, in a volume which one
would wish to carry upon his travels —WiLL1AM S. Cooper.
A Yosemite flora
Professor and Mrs. H. M. Hatt of the University of California are pioneers
in the production of a local flora or handbook of one of our great natural
playgrounds. Scores and scores of other local floras have been produced,
but these have been as a rule mere check lists, and in all cases were intended
to meet a local need. In this Flora of the Yosemite? we have a handbook that
will find its largest use among strangers to the region. It is hardly necessary
to call attention to the small size of this National Park as compared with the
ize of the great state of California, nor to the great size of the Park botanically
eat Within its 1024 square miles there are probably more kinds of
il and climate than can be found in any equal area in the world. This
varied topography and climate have supplied the 955 species included in the
flora. The grasses, sedges, and rushes are not included, but the authors
conservatively estimate that these would swell the number to 1200, a number
probably as great as that of an entire state in the prairie region.
2 Hatt, Harvey Monroe and Cartotra Case, A Yosemite flora. San Fran-
cisco: Paul Elder & Co. $2.16.
168 BOTANICAL GAZETTE [AUGUST
The book possesses practically every feature that will contribute to its
usefulness: an introduction to the Park itself; a chapter on the organography
of the plant for those who have not had a course in botany; simple but com-
plete keys; plain concise descriptions with a minimum of technical term
interesting notes on habitat, habit, distribution, etc; 11 beautiful salfeehi
plates in brown, and 174 instructive figures; a glossary and a complete index.
This little manual of sae 300 ae is ee in many ways. It indicates
an increasing interest in technically ply and clearly expressed.
It emphasizes the fact that systematic botany should be developed for the
_ use of the people, not to impress them with the futility of trying to fathom
the mysteries of recent nomenclatural practices. It shows that the breeze
is beginning to blow steadily from the ocean, littered with the wreckage of
amilies, genera, and species, to the solid shores on which an Astragalus is an
Astragalus and not a Tium; a gentian is a gentian and not an Anthopogon;
anda pine is a pine and not an apine.
When a thing is so well done it seems almost ungenerous to mention
matters which represent merely differences of opinion, but would it not have
been well to have included the grasses, sedges, and rushes for the sake of
completeness? Botanists would have valued this feature even if the descrip-
tions had been very much curtailed. Attention may also be called to the seem-
ing ultra-conservatism of the authors in the matters of the adoption of recent
names for old, well known species. To a beginner, one technical name is as
good as another, and no useful purpose is served by retaining a name that
properly a in another range, even though that name has long been
used in ou
The publishers have done their work well. The binding is limp leather,
the paper excellent in quality, and the pages are trimmed close, so that the
little volume feels good in the hand and will no doubt find its way into the
pockets of many of the visitors to the Yosemite Park.—AVEN NELSON.
NOTES FOR STUDENTS
Current taxonomic literature.—L. R. Aprams (Muhlenbergia 8: 26-44.
1912) gives a synoptical revision of the genus Monardella, as represented in
southern California, and adds 4 new species, and 3 varieties —O. Ames (Tor-
reya I2:11-13. 1912) has published a new Habenaria (H. Brittonae) from
Cuba.—J. C. Artuur (Mycologia 4: 49-65. 1912) records the results of con-
tinued studies on the “Cultures of Uredineae in 1911.” —O. BECCARI (Webbia
3:131-165. 1910) under the title “Palmae australasiche nuove o poco note”
has published several new species of palms and proposes a new genus (Pril-
chardiopsis) of this any from New Caledonia. a — (Rep. mide ey,
10: 280, 281. 1912) ch
based on the Mexican plant Nama glandulosum Peter, The s: same author
(ibid. as proposes the name Andropus carnosus for the plant hitherto doubt-
Igt2] CURRENT LITERATURE 169
fully referred to the genus Conanthus—N. L. Britron (Bull. Torr. Bot.
Club 39:1-14. 1912) under the title ‘Studies of West Indian plants IV”
places on record important data and describes 20 new species of flowering
plants.—The same author (Torreya 12:30-32. 1912) adds a new species to
the recently monographed genus Hamelia, namely H. scabrida from Jamaica.—
N. L. Britton and J. N. Rose (ibid. 13-16) record 7 hitherto undescribed
species of cacti from Cuba.—E. CHIovENDA (Ann. Bot. 10:25-29. 1912)
under the title ‘“‘Intorno a due nuovi generi di piante appartenenti alla famiglia
delle Malpighiaceae” proposes two genera, namely Tetraspis and Eriocau-
canius.—A. COGNIAUX (Rep. Sp. Nov. 10:343, 344. 1912) describes a new
species of Epidendrum (E. Rojasid) from Paraguay.—L. Drets (Leafl.
Bot. 4:1161-1167. 1911) gives a synopsis of the Philippine Menispermaceae,
recognizing 14 genera; the synopsis is based on a monograph of the group in
the Pflanzenreich by the same author.—K. Domin (Rep. Sp. Nov. 10:57-61,
117-120. 1911) describes several species of flowering plants from Australia
and proposes a new genus (Notochloe) of the Gramineae—A. D. E. ELMER
(Leafl. Phil. Bot. 4:1171-1474. 1911-1912) in continuation of his work on
the Philippine flora has described upward of 150 new species of flowering
4-336.
several specialists has issued “Beitriige zur Flora von Afr
120 species new to science are published, — mostly to the Solanaceae,
Polygonaceae, and Umbelliferae. Four new genera of the Umbelliferae are
proposed, namely Afrosison, M. slate. Volkensiella, and Frommia.—
F. Feppe (Rep. Sp. Nov. 10:311-315, 364, 365, 379, 380, 417-419. 1912),
has published new species and varieties of Corydalis from North America.—
M. L. Fernatp and K. M. Wrecanp (Rhodora 14:35, 36. 1912) record a
new variety of Juncus (J. balticus var. melanogenus) from Quebec.—C. N.
Forbes (Occ. Papers Bern. Pau. Bish. Mus. Ethl. and Nat. Hist. 5:1-12.
1912) under the title “New Hwee plants III” has published 4 new species
of flowering plants.—E. L. Gre NE (Leafl. Bot. Obs. and Crit. 2:165—-228.
1912) has described about 100 new species of North American flowering plants
mostly referred to Apocynum and Erigeron——D. Grirritus (Rep. Mo. Bot.
Gard. 22: 25-36. pls. 1-17. 1911) in a fourth article on Opuntia has described
and illustrated 10 new species from southwestern United States and Mexico.—
W. B. Grove (Journ. Bot. 50:9-18, 44-55. pls. 515, 516. 1912) in an article
entitled ‘“‘New or noteworthy Fungi, part IV” includes the description of a
new genus (Cryptostictella) found on leaves of Tilia europea at Studley Castle,
England.—The same author (ibid. 89-92) has proposed the generic name
Diplosphaerella, to include the species which have 16 spores in the ascus;
the genus is based on Mycosphaerella polyspora Johans.—E. HacKet (Rep.
Sp. Nov. 10:165-174. rgtr) under the title “Gramineae novae VIII”
describes several new species of grasses including 9 from Mexico and South
America.—E. Hassier (ibid., 344-348. 1912) has published new species and
varieties in the Rutaceae, Simarubaceae, and Scrophulariaceae from Paraguay.
170 BOTANICAL GAZETTE _ [auGusT
—A. A. HELLER (Muhlenbergia 7:125-132. 1912) describes and figures a new
species of Ivesia (I. halophila) from the Ruby Mountains, Nevada; and (ibid.
8: 21-24. pl. 4) records a new A pocynum (A. cinereum) from the same state.—
G. Hizronymus (Rep. Sp. Nov. 10:41-53, 97-116. 1911) has published 19
new ral of Selaginella from the Philippine Islands—P. B. KENNEDY
_ napa mis : —— 1912) describes a new willow (Salix caespitosa)
sae — ERN (Torreya I1:211-214. 1911) records
2 new species e penesd from the Central and Southern States.—F. KrANz-
LIN (K. Sv. Vet. Akad. Handl. 46: no. 10. 1-105. pls. 1-13. 1911) under the
title ‘‘Beitriige zur Orchideenflora Siidamerikas”’ has published 78 new species
of orchids, mostly from Brazil. The descriptions are supplemented by illustra-
tions bringing out the more salient floral characters.—G. KtKENTHAL (Leafl.
Phil. Bot. 4:1169-1170. 1911) records a new Carex (C. palawanensis) from the
Philippine Islands.—H. Lfveriié (Rep. Sp. Nov. 10:431-444. 1912) has pub-
lished several new species of flowering plants from China and the Sandwich
Islands and includes a new genus (Esquirolia) of the Oleaceae from China.—
I. M. Lewis (Mycologia 4:66-71. pls. 58-61. 1912) describes and illustrates
a new black knot disease (Bagniesiella Diantherae) found on Dianthera ameri-
cana at Austin, Tex.—J. Lunett (Am. Mid. Nat. 2:169-177, 185-188, 194,
195. 1912) describes new species and varieties in Laciniaria, Toxicodendron,
which represents a monotypic family (Mitrastemonaceae) of parasitic plants
from the temperate regions of Japan, and regarded by the author as constitut-
ing an independent series (Mitrastemonales) most closely allied to the
Aristolochiales—U. Martetit (Webbia 3:5-35. 1910) presents a synoptical
revision of the genus Freycinetia of the Philippine Islands, recognizing 35
species of which 9 are indicated as new.—W. R. Maxon (Bull. Torr. Bot.
Club 39: 23-28. r9r2) records the results of a study of the genus Phanerophlebia
and gives a key to the 7 recognized North American species—W. MOESER
(Rep. Sp. Nov. 10:310, 311. 1912) characterizes a new genus (Pseudobotrys)
of the Icacinaceae from New Guinea.—W. A. Murritt (Mycologia 4:72-83-
1912) in a fifth article on the “Agaricaceae of tropical North America” treats
13 genera and describes new species in Mycena, Pluteolus, Conecybe, Naucoria,
Cortinarius, Inocybe, and Hebeloma. The same author (ibid. g1~-100) gives 4
list of the Polyporaceae and Boletaceae collected on a recent tour of the Pacific
Coast region; the article includes 8 new species of the former family and 4 of
the latter —J. A. NreuwLanp (Am. Mid. Nat. 2:178-185. 1912) describes
two new species and four varieties of flowering plants, and (ibid. 201~247)
in an article entitled “Our amphibious Persicarias” discusses several of the
aquatic or semiaquatic smartweeds and proposes 2 additional species in the
group.—J. M. GREENMAN.
1912] ' CURRENT LITERATURE 171
Geotropism.—RITTER; applies the rotation method of Piccarp‘ for
determining the distribution of geotropic sensitiveness in various grass seed-
lings. RurTer states that it is through the application of this brilliant con-
ception alone that the distribution of geotropic sensitiveness has been settled
in some cases.5 In Avena sativa, Hordeum vulgare, and Phalaris canariensis, a
short tip zone of the coleoptile is very much more sensitive than the basal
region, which shows some geotropic sensitiveness. In Avena the very sensitive
zone is 3 mm. long, and in Hordeum and Phalaris 4-5 mm. In Setaria italica
all regions of the coleoptile are Laie sensitive, while i in Sorghum vulgare the
tip region shows slightly greater sensitiveness. Since the main curving is in
the epicotyl, a conduction of the stimulus to that region from the coleoptile
must occur. The distribution of the motile starch in all these organs cor-
responds closely with the distribution of geotropic sensitiveness, so that
RITTER considers the work confirmatory of, or at least not antagonistic to, the
statolith starch theory.
n a study of the geotropism of rhizoids carried out in HABERLANDT’S
laboratory, BiscHorF® comes to the following conclusions: The rhizoids of the
growing gemmae of Marchantia polymorpha and Lunularia cruciata are, con-
trary to the conclusion of WEINERT, positively geotropic, and those of the thalli
show the same character with lower sensitiveness. B1scHoFF asserts that the
lack of motile starch in these rhizoids does not necessarily argue against the
statolith theory, for other motile bodies may take its place. The rhizoids of
ferns are ageotropic. The main rhizoid of mosses (Bryum capillare, B.
argenteum, and Leptobryum pyriforme) is positively geotropic in light, while
the protonemata and side thizoids are ageotropic. In the mosses statolith
starch is found in the main rhizo
Jost and Sropret’ have caatked the interesting fact that under high
centrifugal force of sufficient duration the roots of Lupinus give the negative
geotropic response instead of the positive. For negative response 16 gravities
or more are needed for decapitated roots, and 70 gravities or more for intact
ones. This lines geotropic response up with OLTMANN’s findings for heliotropic
response; one and the same organ responds either positively or negatively,
depending upon the strength of the stimulus. Parallel with heliotropism a
3 RITTE RMAN VON GUTTENBERG, Uber die Verteilung der geotropischen
Empfindlichkeit i in der Koleoptile von Gramineen. Jahrb. Wiss. Bot. 50: 289-327.
#..2. 1012
4 riety W., Physiology. English ed. 3:418-419. 1905.
5 See review of Darwin in Bor. Gaz. 46:387. 1908; also review of HABERLANDT
in Bor. Gaz. 47: 482-483. 1909.
6 BiscHorr, Hans, Untersuchungen iiber den Geotropismus der Rhizoiden.
Beih. Bot. Eee 28: 94-133. 1912
7 Jost, L., and Sropret, R. Séiion iiber Geotropismus. II. Die Verainderung
der ae Reaktion eich Schlenderkraft. Zeitsch. Bot. 4: 207-229. 1912.
E72 BOTANICAL GAZETTE [AUGUST
medium intensity of the stimulus produces no reaction; also the positive curv-
ing occurs in the zone of most rapid growth, while the negative takes place in the
region of greater maturity. The quantity of stimulus law already established
for heliotropism and geotropism! is confirmed by this work. The quantity of
stimulus necessary for a negative response is about 1ooo times that necessary
for a positive response.
Jost? takes up the several positive arguments that have been offered in
favor of the starch statolith theory, and with some partisanship shows their
shortcomings. He observes that the negative argument is often used; that
while many facts do not aid in substantiating the theory they at least do not
disprove it. This statement holds, he asserts, because the theory itself has
experienced a gradual process of adaption to the demands of newly established
facts, which makes the theory of 1909 quite a different thing from that of 1900.
In its earlier form the starch must actually fall on the Plasmahaut and lie there
for some time to induce the reaction, while in the later form movement of the
starch without geo-perception is explained by lack of irritability of the plasma,
and geo-perception without movement of starch is explained by saying that
actual displacement of the starch is not necessary for perception.
The author has studied the response of the root on the Piccard centrifuge
and the effect of the removal or injury of various regions of the root tip on
geo-perception and geo-response. The results on the Piccard centrifuge agree
with those of HABERLANDT,” though the author gives them a different inter-
pretation, which he believes accords better with all the facts known. Any
injury that leaves the root tip attached or removes 0. 5-o.75 mm. gives a wound
effect that hinders geo-response for some hours. Removal of 1 mm. or more of
the tip hinders geo-response for many days. Jost believes removal of 1 mm.
or more of the tip affects the response in three ways: by wound shock, by
removing a highly sensitive geo-perceptive region, by removing a region of great
tonic significance in rendering other regions sensitive. His main evidence for
the tonic effect of the tip 1 mm. is the fact that on the Piccard centrifuge the
tip must extend over the point at least 1. 5 mm. to give a reaction in favor of the
tip, showing considerable sensitiveness in the growth zone; while removal of
only 1 mm. of the tip renders the growth zone ineffective. The author believes
that Némec’s conclusion that statolith starch is necessary in the tip for geo-
perception lacks evidence, and that such a conclusion was drawn because
NéEmec failed to recognize the important tonic effect of the tip 1 mm. JOST
believes that the meristem of the tip, along with the cap region immediately
bordering on it on the one hand and the growth region on the other, are the
regions of the maximum sensibility, while other regions may perceive but give
' 8See review of BLAauw in Bor. GAz. 49: 238. 19fo. ;
9 Jost, L., Studien iiber Geotropismus. I. Die Vertiting der eich
Sensibilitat in dex Wareelaiitce Zeitsch. Bot. 4: acon. Age
© See review in Bot. Gaz. 472482. 1912.
1912] CURRENT LITERATURE 173
no results unless the tip is present. The meristem in Lupinus, the form used,
is starch free, consequently this interpretation which seems to agree well
with all facts observed is opposed to the starch statolith theory.—WILLIAM
CROCKER.
Gummosis.—SorAvER,™ in two extensive papers, discusses gum-flow in
the cherry and related phenomena in some other trees. He concludes that the
tendency to gummy degeneration is latent in the cherry tree, and that stimuli
such as frost and wounds only accentuate a natural tendency. Individual
cells in the pith and bast, which in perfectly normal twigs of various
trees show swelling of the walls and discoloration and degeneration of
the contents, exhibit the primary evidences of the terfdency to gummosis.
Through variations in growth that may be regarded as normal, such as unusual
breadth of the medullary rays, or through variations in nutrition affecting
turgor, or through wounds, effects of frost, etc., the tension relations between
pith and wood, and between wood and bark, are frequently greatly altered,
resulting in release of pressure at certain points. At these points, islands of
parenchymatic cells are regularly formed, among and in place of the normal
prosenchymatic cells. This is a common phenomenon in many trees, without
gummosis following; but in the cherry such islands of cells are the usual foci
of gummy degeneration. They are particularly numerous in the wood formed
by late fall growth; consequently different parts of the same branch or tree
vary enormously in the tendency to gummosis.
ells having the tendency to gummosis are deficient in starch, thin-walled,
with heavy deposits of tannin and phloroglucin; in a word, they-are cells which
fail to mature. The cause of degeneration may be regarded as an excess of
enzymes; degeneration in the individual cell starts in the cell contents, and
extends to the secondary membrane, which swells and furnishes the chief
material for the gum. As the gummosis extends to adjacent cells the order
is of course reversed, the intercellular substance being first attacked, the cell
contents last.
The bulk of these papers is devoted to a minute description of the histology
and microchemical reactions of a great quantity of material illustrating various
aspects of the gummosis problem. In addition to various species and varieties
of Prunus, the following species are studied: Corylus avellana, Pinus Laricio, P.
silvestris, Fagus silvatica, Fraxinus excelsior, F. Ornus, Syringa vulgaris, Cytisus
Laburnum, Tilia sp., Ampelopsis sp., Platanus sp., and the pear. Scant atten-
tion is given to the work of previous investigators. These papers are of great
value for the abundance of detailed observations, but the logic of the deductions
is at times difficult to follow.
.
SoRAvER, Pau, Untersuchungen iiber Gummifluss und Frostwirkungen bei
Kirschbiumen. Landwirtsch. Jahrb. 39:259-207. pls. 5. 1910; and 41:131-162.
pls. 2. 1911.
174 BOTANICAL GAZETTE [AUGUST
BUTLER” rejects the earlier view of BEIJERINCK and RANT, that gummosis
is due to a cytase which, unable to attack the wall of a living cell does so as
soon as the cell is injured from any cause. He also rejects RUHLAND’S view
that the gum is an oxidation product of carbohydrates and that gummosis is
caused by admission of air through wounds. BuTLER considers that ‘“gum-
mosis is due to hydrolysis of the walls of the embryonic wood cells, which
develop into a susceptible tissue.’”’ The form of development of a spot of
gummosis shows, however, that it is correlated with release of pressure of the
cortical tissues. Gummosis does not occur unless the cambium is growing
actively and there is an abundant supply of water available to the roots; when
or
Contrary to previous investigators, BUTLER states that starch and other cell
contents play no part in gum formation. ‘‘Gummosis of Prunus and gummosis
of Citrus are indistinguishable maladies.” Both squamosis and exanthema are
considered to be forms of gummosis. An excellent bibliography is appended.—
VEN METCALF.
Root habits of desert plants.—In studying the roots of plants growing
near the Desert Laboratory, Tucson, Ariz., CANNoN® has made a rather
detailed investigation of more than 60 species, including winter and summer
annuals as well as various types of perennials. Three general types of root
systems are recognized, namely, a generalized system with both tap and lateral
roots well developed, a specialized type with the tap root the chief feature,
and a second specialized type in which the laterals, placed near the surface
of the ground, are especially well developed. The cacti are almost the sole
representatives of the last type, and represent a specialization of a xerophytic
form capable of absorbing a water supply from rains which penetrate a few
centimeters only. This type seems necessarily limited to plants with very
considerable water-storage capacity. A further specialization in the roots of
most cacti is to be seen in the development of an anchoring and an absorbing
system.
Plants having prominent tap roots include comparatively few species.
They are mostly perennial in habit and limited in their distribution to areas
with considerable depth of soil. In contrast, the generalized system is charac-
teristic of the majority of both the perennial and annual species. It facilitates
distribution because of its plasticity, and because its representatives are found
in widely varying situations. It is to be regarded as the least xerophilous of
” BUTLER, OrmonpD, A study on gummosis of Prunus and Citrus, with observa-
tions on squamosis and exanthema of the Citrus. Ann. Botany 25:107-153- ls. 4-
IQII.
3 CANNON, W A., The root habits of desert plants. Carnegie Institution of
Washington. ek No. 131. pp. 96. pls. 23. 1911.
1912] CURRENT LITERATURE 75
the three systems, and hence includes almost all the annual plants. Few of
these annuals penetrate the soil deeper than 20 cm., and most of the lateral
branches are less than half this distance from the surface. Competition is
evident between the various members of the generalized type, and also between
them and those of the first specialized class. The best development of root
systems is found in the summer annuals, due to more favorable vegetative
conditions, and particularly to more favorable soil temperature during that
portion of the year.
The details of root development in the various species are illustrated by
many photographs and drawings, while the detailed descriptions contain many
interesting facts concerning the different plants—Gro. D. FULLER.
Chromatophores and chondriosomes.—FoORENBACHER™ has made a
study of the origin of chloroplasts and leucoplasts in the stem and root of
Tradescantia virginica, the object of which is to show the origin of these struc-
tures from chondriosomes (filamentous mitochondria). Beginning with the
fully formed chloroplasts of the stem cortex and leaves and proceeding toward
the tip, he finds a complete gradation between the fully formed chloroplasts
and the chondriosomes. The intermediate forms present themselves as dumb-
root tip and the leucoplasts. This work thus confirms the results of PENSA
and Lewirsky and those of GUILLIERMOND on the origin of the chloroplasts
from oe (chondriosomes).
me doubt is justified of the efficiency of the methods employed for
Sie tie the chondriosomes of plant cells. Merves, for example, foun
these structures in the tapetal cells of Nymphaea, but not in the spore mother
cells, in which, however, by suitable methods they may be shown to be very
numerous. The reason was the small power of penetration of the fixing
fluid, which did not reach the deeper tissues before the mitochondria had
undergone change or disappeared. In eliminating acetic acid wholly from
tration. His figures are not convincing, for the structures labeled as chondrio-
somes do not conform in shape or number to the usual condition in rapidly
dividing cells of higher plants. It is quite possible that his young chloroplastids
do not belong to the category of mitochondria (chondriosomes) at all.—R. R.
BENSLEY.
Vascular anatomy of Salicales.—Miss HoipEN*™ has investigated the
position of Salicales on the basis of the vascular anatomy of the North American
“4 FORENBACHER, AUREL, Die Chondriosomen als Chromatophorenbildner. Ber.
Deutsch. Bot. Gesells. 29: 648-660. 25. Igtt.
*s HoLpen, Rutu, Reduction ae reversion in the North American Salicales.
Ann. Ea 26: 165-173. pls. 20, 21. 1912.
176 BOTANICAL GAZETTE [AUGUST
representatives. In the ENGLER arrangement, based on floral characters,
they are one of the three most primitive groups of the Archichlamydeae.
Most of the eastern representatives of the group have uniseriate rays and
“‘terminal” parenchyma (‘‘only at the end of the annual ring”) in the stem
cylinder, but in the conservative regions multiseriate rays and vasicentric
parenchyma are found. This latter combination is found also in the stem
cylinders of certain western forms. e conclusion from these facts is that
multiseriate rays and vasicentric parenchyma represent the primitive con-
dition of the group, and that their present simple structure is due to a reduction
from a more complex structure. This means that, according to the testimony
of vascular anatomy, the Salicales should be transferred from a very low
position to a relatively high one among the Archichlamydeae.—J. M. C
The fruit of Compositae.—LaviALLE™ has begun the publication of a
volume of observations on the development of the wall of the akene of the
Compositae, a complex of testa and pericarp. The first chapter and part of
the second have appeared in the Annales as cited. Since 2098 species, repre-
senting 65 genera, have been studied, the number of observations are very
great. Just what the value of them will be is also obvious. In the account
of the “actual state of knowledge of the structure of the fruit of Compositae,”
the actual state of knowledge of the author is very apparent. The citations
are few, and apparently no contributions in English were available—J. M. C.
A new Cordaites.—Miss Brnson” has described a new species of Cor-
daites from a fairly well preserved specimen obtained from the coal mines at
Shore, England. It is compared with related species, and the intimation is
given that along with C. Wedekindi Felix it may represent a new genus, whose
seeds are already suspected to be those of a Mitrospermum closely associated
with it in the deposit. The whole leaf is said to have ‘‘a markedly xerophilous
character.”—J. M. C
soe Se r., — sur le développement de l’ovaire en fruit chez les
posées i. Nat. Bot. IX. 15: 39-64.
17 BENSON, pasa Cordaites Felicis, sp. nov., a cordaitean leaf from the
Lower Coal Measures of England. Ann. Botany 26: 201-207. pl. 22. fig. I. 1912.
Vol. LIV No. 3
THE
BoTANICAL GAZETTE
september ro1r2
Editor: JOHN M. COULTER
CONTENTS
The Life History of Aneura pinguis ; Grace L. Clapp
Plant Geography of North Central New Mexico J. R. Watson
The Perfect Stage of Actinonema rosae Frederick A. Wolf
Undescribed Plants from Guatemala and Other Central
American Republics. XXXV John Donnell Smith
Influence of Phosphate on the Toxic Action of Cumarin
J. J. Skinner
Briefer Articles
Absorption of Barium Chloride i Aragallus Lamberti
C. Dwight Marsh
Current Literature
The University of Chicago Press
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THE MARUZEN-KABUSHIKE-KAISHA, Tokyo, Osaka, Kyoto
The Botanical Gazette
: 2B Monthy Journal Embracing all Departments of Botanical Science
Bdited by JoHN M. CouLTER, with the assistance of CE members of the botanical staff of the
University of Chic :
Issued September 21, 1942
Vol, Liv. tas ‘CONTENTS FOR SEPTEMBER 1912 _No. ai¢
THE LIFE HISTORY OF ANEURA PINGUIS.. Conrrrputions From THE Hutt BoTanicaL.
-LAwoRaTorY I 50 (WITH PEATES Ix-xt1). Grace L. Clapp: °- - -
| , PLANT GEOGRAPHY OF NORTH CENTRAL NEW MEXICO. Coxrersutions FRoM se ::
4 £48 Biot Borantcap LABORATORY 160 (WITH SEVEN FIGURES): J. R. Watson +o “4 £98. x
THE PERFECT STAGE OF ACTINONEMA ROSAE (witn pLate xr). Frederick A. Wolf. 218
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, REPUBLI | es XXXV. John Donnell Smith - 335 <a
~ INFLUENCE OF PHOSPHATE ON THE TOXIC ACTION OF CUMARIN. . J: J. Sion 245
BRI EPER ART T CEES + . ae ; :
ABSORPTI ON OF Batu Cuonipe BY. ARAGALLUS 5 Lasteserr "pe one Marsh 2 Saye
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VOLUME LIV NUMBER 3
PIT
BOTANICAL <GAZETTE
SEPTEMBER 1912
THE LIFE HISTORY OF ANEURA PINGUIS
CONTRIBUTIONS FROM THE HULL BOTANICAL LABORATORY 159
GRACE L. CLAPP
(WITH PLATES IX~—XII)
Historical
In his classical study of liverworts, LErTGEB (19) has given a
comparative treatment of the genus Ameura. Stages of develop-
ment chosen from several species picture the life history of the
genus rather than that of any one species from spore to spore.
HoFrMEIsTER (13) earlier described the apical cell and sex organs of
Aneura pinguis, and Kny (15) worked out in an elaborate scheme
the segmentation of its apical cell. Le Crerc pu SaBLon (18),
GOEBEL (10-12), CAMPBELL (3), and CavERs (4) have since added
facts, but gaps have been left in the continuous development,
chiefly in the embryogeny and in the growth of the sporeling.
Material
Material of Aneura pinguis was collected by Dr. LanpD at
Xalapa, Mexico, in the autumns of 1906, 1908, and 1910. The
region around Chicago has offered abundant supply for field study.
The plants were killed in the field in Flemming’s fluid (weaker), in
alcohol (50 per cent) and formalin, and in chrom-acetic acid without
osmic acid. Following the close series of alcohols in dehydration,
the material imbedded in paraffin was cut in sections 3-10 » thick.
Safranin and anilin blue, Haidenhain’s iron-hematoxylin with and
without Magdala red, and Flemming’s triple stain were used for
177
178 BOTANICAL GAZETTE [SEPTEMBER
stains. Shrinkage in the young embryo and resistance to infiltra-
tion of the mature capsule were the chief difficulties met.
Thallus
SCHIFFNER (23) describes Aneura pinguis as a cosmopolitan
species, strictly dioecious. LAND reports the growth of the species
on decayed fallen logs in the rain forest as most luxuriant. The
plants exceed only slightly, however, those growing in the hydro-
mesophytic habitats of Chicago. On fallen hemlock logs in shady
ravines and on the mossy edges of pine-oak dunes bordering sloughs
the plants form a close mat. Wherever moss forms a humus layer
along the lines of seepage of the clay bluffs along Lake Michigan,
the thalli are also found. In the prairie meadows Aneura pinguts
often extends half an inch on Typha and Acorus leaves or grows on
clumps of exposed grass roots. In all these places moisture,
diffused light, and fairly low temperature are the favorable condi-
tions for its growth. Plants grow fairly well in the laboratory
when these conditions are imitated.
Aneura pinguis is strictly dioecious, but both kinds of plants
grow side by side in the field, often with margins overlapping (fig. 1).
In general the thallus is a flat ribbon-shaped plant closely appressed
to the ground, with frequent branches, and slight indentations
along the margins. While it averages 5—7 mm. in width, it may be
reduced when growing in a moist chamber with light from one side
in the laboratory to less than 2 mm. (NEMEC 21).
The thallus consists of compact cells, unequally elongated in the
direction of the main axis of the plant. Although it lacks a midrib,
the plant is usually thicker along the center, thinning out toward
the lateral margins. All the cells contain chloroplasts at some
time and the plastids often have 5 or 6 starch grains. Ordinarily it
is 1012 cells thick. There is no definite differentiation into tissues,
but the superficial layer is clearly composed of smaller cells with a
larger number of chloroplasts. This dorsal “small-celled epider-
mis” has undergone one more division, longitudinally and trans-
versely vertical, than the layers beneath (fig. 2). Plants in the
shade appear succulent and are deep emerald green in color. The
numerous chloroplasts are found dividing as often as in Funaria
or Elodea.
1912] CLAPP—ANEURA PINGUIS 179
On the ventral surface rhizoids (figs. 13-15) and mucilage hairs
(fig. 12) indicate slight cell differentiation. The rhizoids contain
chloroplasts at first like the other superficial cells (fig. 13). Such
cells project slightly, elongate, the chloroplasts disappear, and the
rhizoids look like root-hairs. As they grow longer the position of
the nucleus changes and the cytoplasm varies in amount and dis-
tribution. Both are near the somewhat thickened tip when the
rhizoid is old. The rhizoids resemble root-hairs in that they become
irregularly lobed in contact with soil particles (fig. 15) and flatten
out in a most deformed way against other thalli and bark.
BOLLETER (2) notes this same lobing in Fegatella conica and it is
common among liverworts. The length and number of rhizoids
varies greatly. In contact with an underlying thallus or bark they
are very short (0.09-0.16 mm.); in soil and moist air they average
less than 1 mm., and only occasionally reach 2 mm. On closely
appressed plants the rhizoids are numerous and scattered; in soil
they grow along the central axis but are never definitely localized.
Irregularity may come from fungi in the rhizoids, and again they
may be as straight as if uninfected. In no case were the lobes of
the rhizoids cut off by walls.
Gemmae have been described by many for Aneura pinguis. In
- the material at hand no gemmae were found. If they are charac- _
teristic of this species, their absence must be due to the conditions
under which the plants grew. Evans (7) has found in species of
Meizgeria that gemmae are not likely to appear when the plant is
growing luxuriantly. This would account for their absence in the
field, but one might expect them to appear on plants idee under
less favorable conditions in the laboratory.
Increase in the number of plants is brought about, as in many
other thallose liverworts, by the dying away of older parts, when
branches become the main axes of new individuals.
Aneura pinguis produces three kinds of branches, the ordinary
vegetative ones and those bearing the two different sex organs.
Such branches have their origin in the segments of the apical cell.
All of the descriptions of this cell agree that it cuts off segments
on two sides alternately right and left (figs. 3-11). Vertical
sections through any of the marginal indentations which indicate
180 BOTANICAL GAZETTE [SEPTEMBER
growing points show clearly that its nee axis is the vertical one
(fig. 2).
Very rarely at the forward end of the thallus can only one apical
cell be found (figs. 5, 6). Usually two indentations are separated
by a narrow marginal projection and each sinus contains two apical
cells (figs. 9-11). One set carries on the main axial growth, the
other produces a branch. The apical cell of the branch originates
in a segment of the axial apical cell by a curved vertical wall bent
to the right or left so that it strikes the wall of the segment opposite
the last cutting one. |
The more rapidly growing dorsal surface carries the apical cell
to the ventral side (fig. 2). The wall-formation in either direction,
therefore, shows an obliquity which later is distinctly vertical or
horizontal. The primary segment is divided by a vertical trans-
verse wall into an inner posterior cell and an outer anterior marginal
one. Walls parallel to the surface come in now, followed by more
vertical ones. The order of vertical, transverse, or longitudinal
does not seem fixed. Clearly these three directions give thickness,
length, and width to the thallus.
If the growth of two apical regions is nearly equal, the thallus
appears dichotomously branched; if one grows faster, the other is
. recognizable as an indentation on the lateral margin, where it may
remain growing very slightly if at all; or if the main axis be injured,
it becomes the apical region of the main thallus, growing rapidly.
Characteristic of the apical cell are the mucilage hairs borne on
the ventral surface of the thallus (fig. 12); 6-10 of them curve
inward and upward around the growing point. Kwny and LEITGEB
describe the mucilage cells as bearing no direct relation to the
thallus in arrangement. They show an alternation, however,
corresponding to that of the apical cell segmentation. The super-
ficial cell from which the hair originates first projects from the
surface, and then divides into two cells. The basal inner cell
retains its plastids permanently; the chloroplasts of the outer one,
after some growth, are transformed into a mucilaginous stuff, which
stains very deeply. These are the hairs which are sloughed off as
the thallus grows. The basal cell divides like any superficial cell.
Apparently it is the posterior ventral surface cell, cut from the
1912] CLAPP—ANEURA PINGUIS 181
primary segment by a vertical transverse and horizontal wall,
which produces it.
Sex organs
ANTHERIDIA.—The antheridia of Aneura pinguis are borne in
the upper surface of lateral branches which occur singly, in groups
of three, or occasionally in groups of two. On the branch their
arrangement is extremely regular, in two alternating rows corre-
sponding to the segments of the apical cell. They appear imbedded
because of the rapid marginal growth of the surrounding cells.
LEITGEB’s diagram for their arrangement in Aneura palmata.
holds true also for Aneura pinguis. After the division of the
primary segment into an outer marginal and an inner posterior cell
by a vertical transverse wall, and after horizontal cleavage of the
latter into a dorsal and a ventral cell, the dorsal cell by a vertical
longitudinal division forms an inner (toward the median axis of the
thallus) and an outer (toward the lateral margin) cell. The inner
by a transverse vertical cut divides into two cells, the anterior of
which gives rise to the antheridium. This dorsal superficial cell
(the antheridium initial), containing a large nucleus and abundant
cytoplasm, enlarges and projects (fig. 16). It divides into two
cells, the outer of which, by a horizontal wall, forms a stalk cell
usually dividing once at least, and the antheridium mother cell (fig.
17).
The method of development follows the Jungermannia type.
. First a vertical wall divides the outer cell into two equal halves (fig.
18). By two vertical intersecting walls in each half, a wall layer of
four cells surrounds two central cells—primary spermatogenous
cells (figs. 22, 23). By rapid growth the antheridium becomes
spherical and appears transparent (fig. 26). Its wall cells, however,
contain chloroplasts which persist until the sperm mother cells are
distinguishable.. The wall cells of the upper half grow noticeably
larger than those of the lower half.
No definite cytological study of spermatogenesis was made, but
some few points were noted. No centrosome was evident during
any division of the spermatogenous cells. The diagonal division of
the sperm mother cells separates them by a membrane which
182 BOTANICAL GAZETTE [SEPTEMBER
stains as deeply as does the cell wall of the mother cell. The
oval nucleus stains deeply and soon occupies one end of the pro-
toplast (fig. 27). At the other end, a dark spot appears in the
cytoplasm—the blepharoplast—which gives rise to the cilia. The
nucleus in its growth elongates, soon making a turn around the
cytoplasm. The cilia are not easily distinguished from the coils of
the nucleus. Beside the beak of cytoplasm, anterior to the nucleus
from which the cilia extend, a rounded mass is left at the posterior
end of thesperm. This is a mechanical hindrance to the movement
of the sperms when the cell walls are transformed into a mucilagi-
nous substance and the sperm is often twisted into small spirals
on its own axis (fig. 27). These disappear as soon as space is given,
and at the time of shedding the mass of cytoplasm at the base is
also gone. The body of the sperm is very long and averages about
2.5 times that of the cilia. Cilia 35.2 and sperm 88.7#, in
rough figures, were the measurements of the longest sperms squeezed
out of the antheridium before it had burst naturally. Probably
when shed in the field they have grown somewhat longer.
The antheridia begin to form early in the spring. They develop
in acropetal succession until August, when many of the branches,
as has been noted (Lerrces, CAMPBELL), continue vegetative
growth. The last antheridium formed is sometimes not imbedded,
but superficial, owing to the rapid elongation of the thallus.
ARCHEGONIA.—Aneura pinguis bears its archegonia also on
the dorsal surface of distinct lateral branches (fig. 28). Such plants
have conspicuously light green filamentous outgrowths, varying in
length and width on the lateral margins. These are caused by the
more rapid growth of the thallus edges of the main axis or of the
lateral branch. Again, there may be from one to three branch
primordia; usually, however, one outstrips the others in develop-
ment. Like the antheridia, the archegonia are regularly arranged
in two rows, alternating according to the apical cell segmentation.
The division of the primary segment is as usual. The first dorsal
superficial cell is the archegonium initial. In order of development
it follows the general liverwort type. Three vertical intersecting
walls surround a central cell from which a cap cell is cut off by a
horizontal wall (fig. 29). The central cell gives rise to four neck
1912] CLAPP—ANEURA PINGUIS 183
canal cells, a ventral canal cell, and the egg cell. The archegonium
wall has two layers of cells (figs. 32, 33). The 4-6 canal cells are of
short endurance; their walls break down and the cytoplasm and
nucleus are transformed into a mucilaginous substance. The egg
cell is large and round, its cytoplasm containing many starch
grains (fig. 33). When the cap cells bend back, there is a clear
passage made in the neck to the egg. Fertilization was not
observed.
As soon as fertilization has occurred, the neck and venter cells
divide rapidly, and the whole branch is a thick cushion of cells
projecting beyond the margin of the thallus. Usually only one
embryo grows on a branch, and where two appear they probably
belong to two branches. Two have been reported, however, in one
calyptra (CoKER 6). Occasionally archegonia, immature and after
the egg has been fertilized, are carried with the filaments to the top
of the calyptra in its growth. Lerrces thinks more trichomes are
produced on the torus, but this seems unlikely, for many are
sSloughed off as it develops. Some new rhizoids do grow at the
bulbous base.
Sporophyte
The first division of the egg is a transverse one into epibasal
and hypobasal cells (fig. 34). The hypobasal cell has been said
either to form a few divisions or to grow into a lobed haustorial
_ cell (Lerrces 19). It distinctly becomes a true haustorium (figs.
35, 36), rhizoidal in form. Both cells elongate rapidly; the haus-
torium sometimes lobes and sometimes remains straight. The
epibasal cell is divided by a horizontal wall into two cells (fig. 35)
containing abundant cytoplasm, many plastids, and large nuclei.
In this three-celled stage disorganization of the cells of the calyptra
around the base of the suspensor is striking. The uppermost cell
divides again by a horizontal wall, so that a filament of four cells
is formed, including the haustorium. Vertical walls now come in,
so that there are three rows of quadrants (fig. 36).
The lowest tier next the haustorium now forms two rows (figs.
37, 38), its vertical and transverse walls having no definite sequence.
It corresponds to the foot, and the cells form at first a more compact
184 BOTANICAL GAZETTE [SEPTEMBER
mass than the slender ones above. The uppermost cell arising in
the epibasal row divides to form the capsule; the middle originates
the seta, probably by its intercalary growth as LEITGEB has sug-
gested. When, therefore, the seta consists of three or four tiers of
cells, the capsule is definitely differentiated. It consists of two
rows, each of eight cells. Periclinal walls have cut out a wall layer
one cell thick (fig. 38), leaving a central sporogenous tissue of eight
cells. The lower four divide by horizontal and vertical walls; the
upper also divide, but form only a group of sterile cells—a cap, later
continuous with the elaterophore. The wall of the lower half
becomes two layers by periclinal divisions not at all simultaneous
(figs. 39, 40). The difference in rate of growth from now on is a
striking feature of development in the capsule (LE CLERC DU
SABLON 18). It first shows in the contrast between the lower and
peripheral region and the upper central part. The contents of the
cells differ in size of nucleiand amount of cytoplasm. Cell divisions
are in every direction. The capsule changes from spherical to oval
and elongates rapidly (fig. 41). This difference in rate of growth
accompanies the formation of the elaterophore, but what determines
the rate? The more slowly dividing cells of the upper central
region begin to elongate, and the elaterophore is outlined (fig. 42);
its cells have smaller nuclei and less cytoplasm. Although cell
divisions are fewer along its margin, they must still be considered
sporogenous tissue. Diagonal divisions and radial arrangement of
diamond-shaped cells indicate elongation of the capsule. Cells
continuing the axis of the capsule between the elaterophore and the
base are still rectangular, like those of the elaterophore except in
size of nuclei.
Differentiation among the spindle-shaped cells is the next
evidence of separation of the sporogenous tissue into elaters and
spore mother cells (figs. 43-50). While in the central axis the
elongated diamond-shaped cells appear to form continuous rows to
the base, in the radial peripheral regions this is more uncertain.
The next stage, and a most unsatisfactory one for study, shows a
partial transformation of the walls of the elaters and of the spore
mother cells. The elaterophore forms a central cylinder of long
prosenchymatous cells, the marginal ones of which have a free tip.
1912] CLAPP—ANEURA PINGUIS 185
They contain plastids with starch. The protoplasts of the elaters
and spore mother cells are outlined by a definite membrane at a
distance from the wall. The space between, however, shows less
well defined strands. The nucleus of the elater is large (figs. 44,
45), at the center, extending well across the diameter of the cell.
There are plastids in the elaters, and BOLLETER (2) considers the
elaters in Fegatella feeders of the spore mother cells because
the starch disappears from the elaterophore about this time. The
spore mother cells also have very large nuclei and the form of
the cell is irregularly rectangular to triangular.
The difference in rate of growth noted before between the
peripheral and central regions is much more evident at this stage.
The four lobes of the spore mother cells are well rounded toward the
outer portions of the capsule, while those at the center are just
beginning to be distinct. The nucleus with a clear nucleolus lies
at the center of the lobed cell (fig. 46). Two successive divisions
of the nucleus form the tetrad of spores.
The cell plate becomes continuous with the deeply staining *
membrane of the lobes. This membrane soon ‘differentiates into
another substance, being added to from the interior where its
outline is very irregular. Centrally between the two margins
staining indicates lines of some substance which grow out to the
outer margin, forming at first irregular projections. Meanwhile,
within the protoplast a cellulose layer forms. When the spore is
mature the two wall layers are not distinct (figs. 51, 52). The
protoplast containing chloroplasts seems to be surrounded by a
single brown wall with echinate projections. During this time the
elaters have changed. The cytoplasm has come to form a spiral
along the wall and a broad brown thickening takes its place (fig.
52). Two spirals are not rare and the elaters are often branched
(Jack 14). Probably examination of the chemical changes taking
place in the spore coat would find them similar to those BEER (1)
has found for Riccia.
The cell walls of the elaterophore are thickened in a narrow single
spiral. The two wall layers have ring thickenings in the sterile
cushion at the apex, and in the two upper layers of cells of the
seta irregular thickenings are found. The lines of dehiscence are
186 BOTANICAL GAZETTE [SEPTEMBER
remarkably distinct in cross-section (fig. 54), for the walls do not
change on that side, but remain thin, composed of cellulose.
The seta, measuring about 2 mm. in length, would be described
as having a club-shaped foot if it can be called a foot. Even when
the seta consists of a few tiers of cells, the glandular appearance at
the base is striking. Tissues of the calyptra and seta disorganize so
that at the base of the seta there are always some glandular cells
and others very much crushed. During its growth the bulbous base
of the gametophyte and sporogonium has turned from a horizontal
to a vertical position.
The capsules dehisce progressively along the thallus from early
spring (March) through May. Gorse (10) has well described
the dehiscence and shedding of spores in Aneura palmata. ‘The seta
elongates rapidly (NEMEc 20) from 2 to 30 and more mm., in the
field often twisting on its own axis. Individually its rectangular
cells lengthen from 60 # to 500 and 600 #. This pushes the capsule
far beyond gametophyte and calyptra. Along the well marked
lines between the valves, about one-third of the way from the tip
at the greatest width of the capsule, a splitting begins. The crack
lengthens until with a jerk the valves are bent back. Some spores
are freed now, but the majority are shed by the next movement
of the valve, when its fourth of the elaterophore springs upward
45° or more. Spores and elaters fall together, the tetrad often
complete.
Germination of spores
Plants with capsules about to shed were brought from the field
March 23, April 15, May 17, and May 20, and put on wet cotton
under bell-jars or in large Petri dishes. Spores were sown as soon
as the capsules burst. On sterilized cotton the spores (averaging
60-68 or 70 #) are soon lost. A better medium and more easily
examined under the microscope is made by putting a layer of heavy
white filter paper over wet cotton in a Petri dish. Porous clay
plates are also good. Drop cultures in 0.5 and 1 per cent cane
sugar, 2.5 and 3 per cent glucose, o.5 and 1 per cent lactic acid,
o.3 and 0.6 per cent Knop solution, vegetable lipase, distilled
water, all died after reaching the two-celled stage. The excessive
amount of moisture was one cause of this, for cultures made at the
1912] CLAPP—ANEURA PINGUIS 187
same time on cotton with distilled water and 1 per cent cane sugar
lived. On moist cotton in the sunlight the spores died in the one-
celled or two-celled stage. Other cultures, therefore, were kept in
a room with the window open, so that the temperature varied
roughly with that outside, and the light was kept diffuse by the
window shade. Sowings were made on sterilized clay, sand,
sphagnum, humus, and sand, and kept under bell-jars. Cultures
on rotten wood were spoiled by Pencillium. Although the pots
containing the soils were scrubbed, dried, sterilized over night in a
drying oven above 115° and again with the soils in an autoclave,
many became infected with a species of Chaetomium. This could
have come about when spores were taken out for examination.
' The accompanying table records some of the data.
Sowing BP sn Oe Time Medium Condition of spores
March 23...| June 23 | 3 mos. | H,O oncotton apes! to all stages
‘un,
April 15...| June 17 | 2 _mos.+] clay a majority 2-
celle
April 15...| June 17 | 2mos.+/ H,O on filter over | majority 2-celled
cotton
April 6,..| June 19 | 2 mos.+| H,O on filter over | 2-celled
cotton
May _5...| June 19 | 1 mo. +/| H,O on filter over | 2-celled
tton
May 5 June 17 | 1 mo. so 2-7-celled (fungus)
May 21 June 21 | 1 mo. sand 2-celled
May 21 June 21 | 1 mo. 1% cane sugar filter | 2-celled
n cotton ;
May 29 June 21 | 1 mo i 1-4-celled (Chaetomium)
May 29...| June 21 | 1 mo H,0 filter on cotton | 2-ce
May 29 June 21 | 1 mo. filter over soil 2-4-celled (fungus)
This rough table shows that the rate of development is variable
and slow. The spores of March 23~June 23 were shed ina heap
on the moist cotton in the moist chamber containing the plants
from the field. Here were found two-celled stages and thalli
with branches. Uninfected plants have reached at most 4 and 5
cells, while those with fungi have mature thalli. This differ-
ence is apparently due to some change caused by the fungus.
LEITGEB (19) describes the germination of Aneura pinguis and
A. palmata, but figures only the early stages of A. palmata. He
188 BOTANICAL GAZETTE [SEPTEMBER
says that the spores enlarge strikingly at first, and by one-sided
growth a filament is formed which elongates by apical growth,
forming a cylindrical body. This body branches and in the tip
cell of the main axis and its branches the typical apical cell of the
mature thallus arises.
In Aneura pinguis the spores at shedding contain chloroplasts
as mentioned above (fig. 51). The spore does increase rapidly in
size from 60 and 70 # to go and 100 win a few days. ‘The plastids
are grouped somewhat at one side, where the cell begins to elongate
into a slight projection. A wall divides the spore into two unequal
cells (fig. 56) (this may happen within 1 or 2 weeks); the smaller one
grows until it equals the sister cell. The exospore has not been
split, but has elongated and surrounds the two cells (figs. 57, 58).
The younger cell is now divided, unequally by a vertical wall bent
slightly toward the long axis of the cell (figs. 59, 60). It soon grows
as large as the cell from which it was cut off, and the division could
easily be mistaken for an equal one. This division may also be
horizontal, resulting in a dorsal and a ventral cell. The apical cell
may originate in either one of these two cells, probably the better
lighted one (PEIRCE 22, Lampa 16 and 17, GOEBEL 10-12,
BOLLETER 2, SCHOSTAKOWITSCH 24). This second or third wall
can then be considered the one which marks out the apical cell.
Only one sporeling was found where the exospore had split and
a filament of five cells had grown (fig. 71). The next division comes
when the last cell cut off equals that from which it was cut, and the
new wall again is a vertical one inclined toward the axis of elongation
(fig. 61). This mode of development continues up to the four- and
five-celled stage. The only difference between this apical cell and
that of the mature thallus is the longer time interval between the
segmentation and the division of the segments. In this four- and
five-celled stage the echinate projections of the exospore are still
present, at a greater distance apart and finally disappearing. The
mass of cells looks slightly as has been pictured for Lejeunia serpyl-
lifolia (CAMPBELL 3).
This then reduces Aneura pinguis to the condition described by
GOEBEL (12) for Metzgeria furcata, where the filamentous stage or
Vorkeim consists of one or two cells. The branched filaments are
1912] CLAPP—ANEURA PINGUIS 189
lacking, which must depend upon the conditions of light and
moisture under which they are grown.
Another interesting fact connected with the development of the
spore is that the fungus plays some part in it when present. Where
the spores fell from the capsule and germinated on the cotton, and
in another case where the capsule did not open wide but spores in
the line of the valves germinated, a fungus was found infecting the
plants. These sporelings were all past the two-celled stage (figs.
64-66). The better lighted thalli were forked, possessing mucilage
hairs and rhizoids. In whatsoever way the fungus affects the plant,
development at least is hastened. Fungi have been noted in many
leafy and some thalloid liverworts (NEMEC 20, BOLLETER 2,
GARJEANNE 8, CAVERS 5), but only in one case does GARJEANNE
note a fungus with the spore, and then only as near it.
The infection begins in any cell of the sporeling (figs. 64-66) and
extends irregularly along the lower surface. Large knots of hyphae
are found in the cells. At first the cells are not killed, fungus,
plastids, and nucleus all being present. Gradually the plastids
disappear but the nucleus remains longer. In cells adjoining and
near to the infected ones, starch of the plastids has been transformed
into dextrine.
A majority of the plants of the field are infected irrespective of
habitat. One would like to know whether spores are also infected
early or whether the laboratory conditions were such as to favor
infection. It is hardly probable that any such relation exists
between spores and fungus as BRUCHMANN has found for species of
Lycopodium. It is more likely, as GARJEANNE thinks, a chance
condition, and not at all an endophytic fungus of mycorrhiza plants.
Thalli from the field usually have the fungus a short distance
behind the actively growing region, and sometimes extending along
two-thirds of the dorsal surface. Is it possible that this is one of
the main causes for the dying back of the thallus ?
Rhizoids are commonly filled with strands of the hyphae (fig.
68). Infection of the rhizoids commonly occurs from the thallus,
and when chloroplasts are still present. The elaborate pseudo-
parenchyma of fungi described by NEMEC (20) at the base of the
rhizoids is lacking, but there are knots of hyphae. Rarely, also,
Igo BOTANICAL GAZETTE [SEPTEMBER
are the rhizoids as deformed by the fungus as by the obstacles in
their path of growth.
Inoculations of pure cultures have not been made because of the
desire to get as many sporelings as possible to develop mature thalli. _
Some of the fungi obtained pure were a species of Fusarium, Cepha-
lothecum roseum, a species of Alternaria and of Gloeosporium, and an
unidentified one which grew with Pencillium in an impure culture.
GARJEANNE has found that more than one spécies may be present
at the same time in a rhizoid. It will be interesting to know how
many of the above can infect the spores.
Summary
1. The gametophyte of Aneura pinguis is a simple, slightly
differentiated thallus.
2. Archegonia and antheridia are borne on lateral branches of
dioecious plants; they develop according to the Jungermannia type.
3. The sporophyte of Aneura pinguis is highly specialized.
One-half of the embryo at its first division forms a haustorial cell;
from the other half capsule, seta, and a temporary foot develop.
Sterilization of the tissue of the capsule occurs at three periods:
(1) the wall and apical cushion are cut out; (2) the elaterophore is
defined; (3) sporogenous tissue is differentiated into elaters and
spore mother cells.
4. The capsule splits by four early defined valves. The spores
are echinate and contain chloroplasts at maturity.
5. The protonemal stage is reduced to one or two cells. The
spore coat incloses the very young sporeling.
6. The mature thallus often contains a fungus. Infection takes
place in some sporelings as early as the two-celled stage. Rhizoids
may be infected from the thallus. :
7. No gemmae are found on Aneura pinguis. New plants are
produced by the dying back of the old thallus.
Acknowledgments are due Professor Joun M. Coutter and
Professor W. J. G. LAND, under whose direction this work was done.
THe UNIVERSITY OF CHICAGO
1912] CLAPP—ANEURA PINGUIS IgI
LITERATURE CITED
I. BEER, R. i the development of spores of Riccia glauca. Ann. Botany
20: 275-201. 19
2. BOLLETER, Qs * Fesatels conica. Beih. Bot. Centralbl. 18:327-408. 1905.
3. CAMPBELL, D. H., The structure and development of mosses and ferns.
1905.
4. CAVERS, F., The inter-relationships of the Bryophyta. III. Ana-
crogynous Jungermanniales. New Phytol. 9:108-207. 1910.
, On saprophytism and mycorhiza. New Phytol. 2:30. 1907.
6. Coker, W. C., Abnormalities in liverworts. Bryol. 12:104-105. 1907.
7. Evans, A. W., Vegetative reproduction in Mefzgeria. Ann. Botany
243 271-303. I9To.
8. GARJEANNE, F. M. Anton, Uber die Mykorrhiza der Lebermoose.
Beih. Bot. Centralbl. 15:470-482. 1903.
9. , Die Verpilzung der Lebermoosrhizoiden. Flora 102:147-185.
IQII
10. GOEBEL, K., Archegoniaten studien. 6. Uber Function und Anlegung
der L charlieg Vig tarts Flora 80:1-37. 1895.
II. , Uber die Jugendzustinde der Pflanzen. Flora 72:15-16. 1880.
£2, , Organographie der Pflanzen. 1898-1901.
43; HoFMErstER, W., On the germination, development, and fructification of
the higher Cryptogamia. Transl. by F. Curry. 43-46. 1862.
14. JACK, J. B., Hepaticae Europaeae. Bot. Zeit. 35:83. 18
15. Kwny, L., Beitrige zur Entwickelungsgeschichte der laubigen Lebermoose.
Jahrb. Wiss. Bot. 4:6497. 1865-1866.
16. Lampa, E., Untersuchungen an einigen Lebermoosen. Sitzber. K. Akad.
Wiss. Wien 111:477-487. 1902.
17. , Keimung einiger Lebermoosen. Sitzber. K. Akad. Wiss. Wien
12°779-792. 1903.
18. Le CLERC DU - SABLON, Recherches sur le développement du sporogone des
Hépatiques. Ann. Sci. Nat. Bot. VII. 11:126-180. 1885.
19. LeitcEeB, H., Untersuchungen iiber die pare 1874-1882. Vol.
Die frondosen Jungermannieen.
20. NEmec, B., Die Mykorrhiza einiger Lebermoose. Ber. Deutsch. Bot.
Gesells. 17:311. 1899.
, Die Wachstumsrichtungen einiger Lebermoose. Flora 96:409-
21.
450. 1906.
22. PerRcE, G. J., Studies of irritability in plants: the formative influence of
light. Ann. Botany 20:449-465. 1906.
23. SCHIFFNER, V., Hepaticae in ENGLER and Prantt’s Die natiirlichen
Pilansenternilien I:1-144. 1893-189
24. ScHostakowitscn W., Uber die Reproductions- und Regenerations-
Eracheinungen bei den Lebermoosen. Flora 79:350-384. 1804.
1g2 BOTANICAL GAZETTE [SEPTEMBER
EXPLANATION OF PLATES IX-XII
Fic. 1.—Sketch of dioecious thallus.
Fic. 2.—Vertical longitudinal section through apical cell; 505.
Fics. 3-8. Serial horizontal section through apical cell; 830.
Fic. 9.—Horizontal section of thallus, showing two apical cells; X 505.
Fics. 10, 11.—Horizontal section of thallus showing two apical cells in one
sinus; 830.
Fic. 12.—Young mucilage hairs; 830.
Fic. 13.—Young rhizoid with chloroplasts present; 830
Fic. 14.—Young rhizoid infected by fungus from within; x 830.
Fic. 15 -—Rhizoids with and without fungus, showing irregular form;
X175-
Fic. 16.—Vertical section through antheridium initial; X 505
Fic. 17.—Vertical section, showing antheridium initial divided into stalk
and antheridium proper; 830.
1G. 18.—Vertical ‘Lose through antheridium, showing fitst vertical
wall; X 505.
Fic. 19.—Stages of development in antheridium, showing wall and
spermatogenous cells defined; X 505.
Fic. 20.—Vertical section through antheridium, showing early divisions 0
the oe cells; 30.
Figs. 21-24.—Horizontal sections ae the antheridium, showing its
ectire e X 1650.
. 25, 26.—Vertical sections through older antheridia, diotitiie stalk
cells, as fig. 26 showing the development of the tissue around the antheridium;
X 505.
Fic. st —Stages of development in the sperm; X 2800.
1G. 28.—Horizontal section through an archegonial branch, showing
numerous et a
IG. 29.—Vertical section through young archegonium; X 830.
Fic. 30.—Vertical section through older archegonium; 830.
Fic. 31.—Horizontal section through archegonial neck; 830.
Fic. 32.—Vertical section through mature archegonium; 830
Fic. 33.—Vertical section through archegonium, showing aad cells dis-
organized; 830.
Fic. 34.—First division of the young sporophyte; X10.
Fic. 35.—The haustorial cell of og sporophyte, ay elongated, and
gametophyte cells disorganizing; x r1o4o.
Fic. 36.—Haustorial cell more asta ; the sporophyte proper composed
of four cells; X 1040.
1G. 37.—Foot, seta, and capsule region of the sporophyte marked out;
X 1040.
PLATE X
BOTANICAL GAZETTE, LIV
CLAPP on ANEURA
‘peru
ee e Cx)
Crag Bs
ees
Ze
Rags
Th
a
PLATE XI
BOTANICAL GAZETTE, LIV
(Neer
tee
Jost
B
Nv
Joke
s8ee2
pay vs
s
ae
CLAPP on ANEURA
BOTANICAL GAZETTE, LIV PLATE XII —
r S
CLAPP on ANEURA
1912] CLAPP—ANEURA PINGUIS 193
Fic. 38.—The primary wall layers and sporogenous tissue differentiated;
X 1040.
Fics. 39, 40.—Older stages of the sporophyte; the cushion of sterile cells
and sporogenous tissue differentiated; X 1040.
.—Older sporophyte showing the meristematic region of the
sporogenous tissue; X 505.
Fic. 42 <Dpalisekiion of elaterophore beginning; X 505
Fics. 43-50.—Young elaters and spore mother cells; x 1650.
Fic. 51.—Mature spore; 1650.
Fic. 52.—Occasional form of mature spore; 1650.
Fic. 53.—Branched elaters; 830.
Fic. 54.—Cross-section of capsule, showing lines of dehiscence; 830.
Fic. 55.—Germinating spore, swollen; 830.
Fic. 56.—First stage of germination; X 830
— 57, 58.—The same stages a little later; X 1040
Fics. 59-63.—Stages in germination; spores developing on wet cotton;
ee) by fungi; 830
Fics. 64-66.—Apical afl of thallus defined; fungus present; X 830.
iis 67, 68.—Older thalli showing fungus present in darkened region;
30.
Fic. 69.—One of the larger thalli, developed in capsule shown in fig. 70;
X 830.
Fic. 70.—Capsule showing thalli from split valves; 830.
Fic. 71.—Germinating spore without fungus; X 1040.
—
PLANT GEOGRAPHY OF NORTH CENTRAL
NEW MEXICO:
CONTRIBUTIONS FROM THE HULL BOTANICAL LABORATORY 160
J. R. WATSON
(WITH SEVEN FIGURES)
The area included in this investigation comprises the northern
half of New Mexico, the most detailed study having been made of
Bernalillo and portions of the adjoining counties containing a
section of the Rio Grande Valley and the Sandia Mountains, but
the results have been confirmed by excursions to other portions
of the northern half of the territory.
The 35th parallel passes through the region under consideration,
which indicates a hot sun during the summer and a warm one
during the winter. The altitude ranges.from a little less than
5000 ft. in the valley of the Rio Grande to about 11,000 ft. on the
northern part of the Sandia Range.
The topography is varied. The recent valley of the Rio
Grande, occupying the center of our region, is two or three miles
wide. The floor is composed of beds of a hard clay (“adobe”),
sand, and gravel. The water level is here usually only a foot or
two below the surface and near the river often rises above it, leaving,
when the water evaporates, a crust of alkali which whitens the
ground like hoar frost on a November morning. The river is a
shallow, muddy stream with a fall of five feet per mile. It may be
a half-mile or more wide during the June melting of the snow on the
Colorado mountains, or entirely dry during August, under the
combined influence of drought and the demands of the irrigation
ditches above. At low water it exposes extensive mud flats on
which a vigorous plant growth quickly develops.
On either side this recent valley is limited by the much dis-
sected edge of the mesa, which rises 100-300 ft. in a mile or two.
These hills, although known locally as ‘sand hills,’ may be com-
* This study was undertaken under the direction of Dr. HENRY C. COWLES.
Botanical Gazette, vol. 54] [194
1912] WATSON—PLANT GEOGRAPHY OF NEW MEXICO 195
posed of sand, hard adobe, or a clayey gravel with stones up to
the size of a man’s head thickly strewn over the surface; or, more
usually, all of these deposited in alternate layers, showing plainly
its fluviatile origin. On the west side of the valley are occasional
sand dunes bearing absolutely no vegetation. |
From these hills a clinoplain, known locally as “the mesa”’
(not a true mesa), slopes gradually upward toward the mountains
with a quite uniform grade of nearly 100 ft. to the mile, although
appearing to the eye to be nearly level or gently undulating. This
mesa is also of stream origin, consisting of the ancient gravels
and clays of the Rio Grande intermixed with sand fans and other
detritus resulting from the weathering of the mountains. On the
east this plain stretches for nine or ten miles to the base of the
Sandia Mountains, forming one of those old western river valleys
so admirably described by MacDovucat.? Every two or three
miles this mesa is crossed by a sandy “arroyo,” or dry stream
bed, which once or twice each summer becomes a raging torrent
for an hour or two. These arroyos lie in shallow valleys, the
largest, however, having banks roo ft. or more high. Few of these
arroyos reach the river proper, but spread their flood waters over
the floor of the recent valley, building up fans of an alluvium-
like clay at their mouths. Numerous smaller arroyos head on the
“mesa’’ proper or on its dissected edge. A similar mesa on the
west side of the valley is partly covered by a flow of lava so recent
that it has suffered almost no weathering, the shallow soil that
covers it, to the depth of a few inches, having been deposited by
the wind. A mile or so back from its edge this lava field is sur-
mounted by five volcanic cones, the largest being about 300 ft.
high.
From the eastern mesa the Sandia and Manzano mountains
rise rather abruptly, sand and gravel fans at the mouths of the
canons forming a transition. The range isa typical block mountain
with the principal fault at its western edge. It is composed of
Archean granites and schists, capped by a layer of Carboniferous
limestone 50-200 ft. in thickness. This limestone shows a dip to
the southeast of about 20°. To the east of the main ridge lie
* MacDoveat, D. T., Botanical features of North American deserts. 1908.
196 BOTANICAL GAZETTE [SEPTEMBER
mountains of less elevation and Permian beds of red clay. Ten
miles east of the Sandia Mountains the Ortiz and San Pedro
mountains rise to an altitude of 8000 ft., followed by the fertile
prairies of the Estancia Valley.
Climate
The most important factor in the climate is aridity. The
precipitation at Albuquerque averages 7.43 in. per year; that of
the mountains is much greater, but unfortunately has never been
measured. Perhaps 20-24 in. would be a fair approximation for
the higher parts of the range. The distribution of the rainfall is
also an important factor. At Albuquerque the average for ten
years was as follows:3
Jan. Feb. March April May June July Aug. Sept. Oct. Nov. Dec.
O65 0.45. 0°92 6.26 0.69 6.35 2.45 1.07 1:7 6.77 0:40.02
It will be noticed that there is a rainy season beginning in July
and one of less intensity in May. This is valuable to vegetation,
as the bulk of the precipitation comes during the warm season.
It would appear from observation that a precipitation of less
than 0.25 in. has no effect on vegetation, with the possible excep-
tion of some of the shallow-rooted grasses, as it does not penetrate
the thirsty soil to a sufficient depth to reach the roots. On the
other hand, much of the summer rain comes down in such a deluge
that a goodly percentage runs off the mesa and especially its foot-
hills. The distribution and the amount are both highly variable
and materially influence the aspect of the vegetation from year to
year. The May rains especially often fail altogether, and it is
said that during a recent drought Albuquerque received not a drop
of rain for thirteen months.
The distribution of the precipitation in the mountains is radi- *
cally different. Judging from observation, the summer rains are
about 50 per cent in excess of those at Albuquerque. But while
snow is rare in the valley, the higher parts of the mountains are
covered with it for a considerable part of the winter, and snow-
storms frequently occur over the whole of the range and extend
down some distance on the mesa. This snow, slowly melting,
3 Macnusson, C. Epw., Bull. Univ. N.M. no. 5.
1912] WATSON—PLANT GEOGRAPHY OF NEW MEXICO 197
thoroughly saturates the soil; much more so than the often tor-
rential rains of the summer which quickly run off. The writer
has been surprised to observe how brief an influence these summer
rains have on the mountain streams and springs. A day or two
after a heavy shower they are nearly as low as before, although they
may have poured out a deluge for an hour or two. A heavy winter
snow, on the contrary, maintains a steady flow throughout most
of the summer.
TEMPERATURE
Because of its altitude and southern latitude, the climate is char-
acterized by a comparatively low mean annual range of temperature
and a high daily range. Although the thermometer is known to go
to zero or below at night, the mean for January is 34° F. (MaGNusson,
loc. cit.). This is due to the high temperature in the middle of the
day (average maximum 46°). For July the mean is 76.4° F., the
average maximum 89,4 and the average minimum 63.5°. The
absolute maximum for the ten years was 104° F., and it has exceeded
too F. on three different occasions. It is the occasional low
temperatures which render it impossible for the larger, thicker
cacti and century plants, so characteristic of southern Arizona and
Mexico, to grow here. They have been planted repeatedly on the
campus of the University of New Mexico, only to perish during
the winter.
EVAPORATION FROM A FREE WATER SURFACE
The following data (Macnusson, loc. cit.), giving evaporation in
inches, show that the ratio of evaporation to rainfall is more than
Io tor:
Jan. Feb. Mch. Apr. May June July Aug. Sept. Oct. Nov. Dec.
2.04 2.63 6.17 6.82 10.08 12.63 11.78 10.21 8.00 4.38 1.73 1.4
Total for the year 77.87 inches.
SOIL MOISTURE
Measurements of soil moisture gave the following results: sandy
soil in the valley in December (dry season) 0.8 in. below the
surface, 30 per cent; sandy soil in the “highlands” (edge of the
4A striking characteristic of the arid southwest is the great difference in tem-
perature in the sun and in the shade.
198 BOTANICAL GAZETTE [SEPTEMBER
valley), 1.9 per cent; sandy clay on the mesa, 3.9-10 per cent;
sandy clay in May on the mesa, 4.8~—7.2 per cent.
CAPACITY FOR HOLDING MOISTURE
Some determinations were made to determine the capacity for
holding moisture, following the method used by LIVINGSTON,°
with the following results. In the first column is shown the per
cent of water absorbed in proportion to the dry weight of the soil;
while in the second column the per cent of water is calculated in
terms of “wet volume,” that is, the volume of the dirt when allowed
to settle under water. There is practically no humus in any of
the mesa soil. In the pifion association there is a little humus,
in the yellow pine association more, while in the Douglas spruce
there is abundant humus.
Open mesa (Gutierrezia association)......... 23.8 per cent 37.3 per cent
Bigelovia association (edge of mesa) where
Bigelovia was most luxuriant........... 21.4 ie
Hymenatherum society of the association....12.7 - 25.8
WIND
A factor influencing the evaporation from plants is wind.
Although the average velocity is probably not great, autumn and
early winter being especially calm, there occur, especially in late
winter and spring, violent windstorms which pick up the sand and
even pieces of gravel large enough to break the glasses of a man
' walking against it. These violent winds plants must encounter,
and this may be the factor which prevents the growth of lichens
on the rocks on the mesa. The prevailing direction of the wind is
south and southwest. This seems to be the explanation of the
presence of sand dunes on the western edge of the valley and their
absence on the eastern side.
: LIGHT
In this clear atmosphere the illumination is of course intense
and very annoying to the traveler in summer. Concerning the
percentage of cloudiness MaGNnusson presents the following aver-
s Livineston, B. E., Relation of desert plants to soil moisture. Bor. Gaz. 50+
241-256. 1910.
1912] WATSON—PLANT GEOGRAPHY OF NEW MEXICO 199
age for ten years: days entirely clear, 219.4; days partly clear,
104.9; days cloudy, 38.4.
Plant formations and associations
Floristically the country is very interesting, as it is the meeting
place of the northern and eastern flora with that of the arid south-
west. On the slopes of the mountains the botanist familiar with
the flora of the east would be able to recognize at least the genus
of nearly every plant encountered, while upon the mesa, with the
exception of Gaura and Salsola, scarcely a genus would be familiar.
RIVER VALLEY FORMATIONS
1. Cottonwood forest
Along the Rio Grande, where the water-table is never very far
from the surface, there occurs an open and more or less pure forest
of Populus Wislizenii. The trees are small, due probably to the
operations of the native ranchers in their search for fuel and fence
posts, for individual trees of this species planted in dooryards are
veritable giants in girth. Scattered throughout this forest and
especially along the banks of the streams are a few willows, clumps
of the shrubs Baccharis Wrightii and Cassia bauhinioides, while on
the ground grow Juncus balticus, Trifolium Rydbergii, Aster spino-
sus, and a little grass. This forest is monotonously uniform and
poor in species.
2. Juncus-Houltuynia association
Alternating with the last in its possession of the river banks
is a meadow-like association of which Juncus balticus and Hout-
tuynia californica are the dominant plants. Just what factors
determine which of these two associations will take possession of a
given area is not clear to the writer. However, it would seem that,
given time enough, the cottonwoods will occupy most of the
situations. The Juncus-Houttuynia association, however, is not a
necessary stage in the formation of a cottonwood forest, as the
latter may develop directly from a mud bank. Whenever a mud
bank is exposed for a few weeks in summer, a vigorous growth at
once appears, of which young cottonwoods, willows, cat-tails, and
200 BOTANICAL GAZETTE [SEPTEMBER
cockleburs are the dominant species. If one looks closely, many
small annuals and numerous specimens of Riccia fluitans are seen;
but one misses the bulrushes and sedges he would find in similar
places in the east. The usual fate of such young growth is to be
washed away upon the return of high water, but should this fail
to happen for a year or so, the young cottonwoods may be large
enough to hold the soil, and a forest develops. Other character-
istic plants of this association are Baccharis Wrightii, Helianthus
annuus, Dysodia papposa, Onagra Jamesii, Amorpha fruticosa,
and Rumex Berlandieri. In more sandy places one meets Aster
spinosus, Maurandia Wislizenii, Sesuvium sessile, and Cycloloma
atriplicifolia.
Much of the valley is under ditch and as a consequence does
not show the characteristic vegetation, but along the ditches a
dense thicket usually develops, composed of Cassia, willows, sun-
flowers, Solidago canadensis var. arizonica, and others.
3. Bigelovia association
On higher ground, where the water level is deeper, there is found
a variety of edaphic plant associations due chiefly to differences
in slope and soil and the consequent ability to hold water. But on
much of this area the dominant plant is Chrysothamnus (Bigelovia)
Bigelovit, a low shrubby perennial, almost leafless, but the green
shoots retain their color throughout the year, so that in winter,
when the prevailing color of the landscape is brown, this formation
may be detected ten miles away. It covers most of the higher
gravel beds of the valley and the dissected border of the mesa, but
stops abruptly and completely at the edge of the more level mesa.
With the exception of the rock surfaces of the mountains, this is
the most xerophytic of all our situations; the steep clay hills
quickly shed what little water falls on them. In sandy places
Yucca glauca is fully as abundant as the Bigelovia, and in places
where a foot or two of sand covers a stratum of adobe, the Yucca
becomes the dominant plant. In places where the sand is deep
and extensive, such as the wider valleys or arroyos, a society, of
which Parosela (Dalea) scoparia is the abundant plant, takes pos-
session of the soil, often to the entire exclusion of Bigelovia, but not
1912] WATSON—PLANT GEOGRAPHY OF NEW MEXICO 201
of Yucca. This plant has slender wandlike branches which are
regularly winter-killed for several inches. Other plants very
abundant here are Croton texensis, the spiny ragweed (Franseria
acanthicarpa), Orobanche multiflora, and Cenchrus tribuloides.
The steeper hills of this formation are too xerophytic even for
Bigelovia, and here the low shrubby composite Hymenatherum
acerosum is the most abundant plant. Associated with it usually
are Crassina (Zinnia) grandiflora, Ephedra trifurca, whose leafless
stems both look and feel like a branched Equisetum, and several
species of Eriogonum. The Crassina has a method of seed dis-
persal that is not mentioned in any text with which I am familiar.
The very large ligules of its ray flowers, instead of dropping off,
become dry and papery, and when the seeds are ripe, the whole
head separates from the stem and goes rolling off over the plain
and hills, a diminutive tumbleweed.
The arroyos of this dissected edge of the mesa show an inter-
esting succession of societies, characterized by successively smaller
plants as one ascends. If sufficiently large to deposit considerable
sand, their lower courses are occupied by the desert willow (Chilop-
sis saligna), a plant with pretty Catalpa-like blossoms. Its leaves,
however, resemble very closely those of such a willow as Salix
longifolia. It is the tallest shrub outside of the mountains and the
cottonwood forest, reaching a héight of 15~20 ft.
Ascending the arroyo this society is replaced by one in which
Fallugia paradoxa is dominant. This rosaceous plant is very slow
to drop its leaves, retaining them until late in the winter. It has
pure white blossoms and plumose fruit. It grows to a height of
3-4 ft. in dense thickets, which are even more dense underground,
where about half of the stems are found, in which respect it
resembles the famous mesquite of more southern regions, the plant
which gave rise to the expression that in New Mexico one “climbs for
water and digs for wood.’ Here grow also two low perennial ever-
green composites, Berlandiera lyrata and Melampodium cinereum.
After the summer rains there appears here, as on the mesa, a rela-
tively abundant growth of annuals, among which the composites
Hymenopappus flavescens, T helesperma gracile, and Baileya mul-
tiradiata, together with Pentstemon ambiguus, are characteristic.
202 BOT. ANICAL GAZETTE [SEPTEMBER
A little higher up, where the arroyo is not over 6-8 ft. wide,
the bed proper is generally free from plants except an occasional
Euphorbia, but the banks are occupied by Bigelovia. Near its
head, where the arroyo is only 1~2 ft. wide, its sides are occupied
by a narrow fringe of shrubs, chief of which are Parosela formosa
and Lycium pallidum.
In the valleys of the larger arroyos that continue the mountain
streams there appears yet another society, characterized by the
dominance of either Suaeda Moquinii, or the greasewood Sarco-
batus vermiculatus, or both, the former being more particularly
confined to the adobe fans at the mouths of the arroyos. Like
so many of the shrubby plants of this region, these and especially
the Suaeda catch the wind-blown dust and allow it to accumulate
among its stems, making mounds like low sand dunes, but in this
case composed of adobe. For this reason this association is covered
with hummocks often 6 and sometimes to ft. high. This is an
alkali society, due to the evaporation of the flood waters of the
arroyo, and has the same relation to the arroyos as a floodplain
forest to a river valley in the east. Mixed with salt grass it is the
dominant association around the salt beds and lakes of the Estancia
Valley, as well as along the Rio Salada branch of the Jemez River.
MESA FORMATION
This occupies the more level ground of the mesa proper and
stops abruptly at its dissected edge, as stated under the last head-
ing. This was undoubtedly originally a grassland, and is so yet
where it has not’ been too seriously over-grazed. It should prob-
ably be classified as a steppe. Now, thanks to lack of scientific
control of grazing, it has been so invaded by the composite Guiter-
rezia (a somewhat shrubby perennial that grows to be 3 ft. high,
and is often called ‘‘goldenrod”’) as to merit being called a Gulier-
rezia formation (fig. 1). The seasons of 1909 and 1910 were drier
than usual until about July 20, and as a result go per cent of the
plants are entirely dead and most of the remainder show only a
small branch or two alive. In the autumn of 1907, after an unusu-
ally wet (or less dry) season, the entire mesa was a sea of gold,
but during those two years it bloomed only in the mountains and
1912] WATSON—PLANT GEOGRAPHY OF NEW MEXICO 203
along trails where there is less crowding and where the dust of the
trail conserves the moisture after the principle of dry-farming.
In 1911 the summer rains commenced in late June and the plants
that survived are thrifty and show abundant bloom.
The mesa is monotonously uniform, especially in winter when
one may ride for miles and see only a few grasses, Gutierrezia,
clumps of Opuntia fragilis, or occasionally a Yucca glauca or a
prickly pear (Opuntia sp.).
I —The head of an arroyo on the edge of the mesa: in the foreground,
Giitsivleie, Salsola, and Yucca glauca; to the extreme left a clump of Chrysothamnus
Bigelovii; in the dhistaiien the ne association.
The plants of the mesa belong to three ecological groups. (1)
Plants like the cacti, Bigelovia, Yucca, Sarcobatus, and Suaeda,
which have large, usually underground stems or roots, in which
moisture is accumulated. (2) Annuals and perennials with under-
ground stems, including by far the largest number of individuals,
but usually not the largest and most conspicuous. They are
plants which are able to wait for the rains and then to make an
exceedingly rapid growth and maturity. Here belong most of the
mesa herbs and grasses. The latter cure perfectly im situ and
make most excellent hay. It is this property of the grasses that
makes the grazing industry possible in this country. (3) The
third class includes a few plants that are winter annuals. The
204 BOTANICAL GAZETTE [SEPTEMBER
fall rains and the occasional snow flurries during the winter afford
them sufficient water for growth in favorable situations, and they
are ready to blossom with the spring rains. The most conspicu-
ous examples in this class are Phacelia corrugata, some of the loco
weeds (Astragulus sp.), Draba, Gilia, and sometimes Gaura coc-
cinea, Sideranthus spinulosus, and many of the plants that are
ordinarily summer annuals may occasionally develop during the
winter and blossom with the first shower of spring or summer.
Indeed, the one feature of the vegetation of this region that attracts
the attention of one accustomed to more humid regions is the
absence of seasonal periodicity on the part of most of the herbs
and many of the shrubs. With regard to relatively few species
can one speak of spring, summer, and autumn flowers here. They
grow and blossom when the rains come, be that March or August.
During 1909 and 1910 the rains came July 20 and July 23 respec-
tively, and the result was that the mesa was brown and lifeless
until then, but by August 1 it was a garden, nearly covered by a
mat of vegetation, made up of grasses, Abronia, Allionia, Town-
sendia strigosa, Houstonia humifusa, Plantago Purshii, Asclepias
brachystephana, Wedelia incarnata, Russian thistle, and Solanum
elaeagnifolium. By September 1o all was over and the mesa had
assumed its usual brown hue. Thus in six weeks the annuals and
the underground perennials had grown, flowered, and matured their
seeds. The exceptions to this rule are those plants in the first
class, the larger shrubs, the cacti, yuccas, and other plants having
thick roots or stems providing for the storage of water. With May
come the blossoms of the stemless evening primroses (Oenothera
sp.), the chimaja (Cymopterus), and the wild onions. When June
arrives, we have the flowers of the cacti, yuccas, and the desert
willow; while September brings out the blossoms of Bigelovia and
October.the Gutierrezia, if there has been rain. This formation
and the next two are classed as Upper Sonoran by Merriam and
his followers.
In the middle of the mesa, 15 miles to the south, the outcrop-
ping of a layer of sandstone causes a succession of springs to appear,
and about these springs are cottonwoods, Juncus, Houttuynia, and
other plants of the valley. In other words, a spring changes Upper
1912] WATSON—PLANT GEOGRAPHY OF NEW MEXICO 205
Sonoran to Lower at once. On the other hand, there appears on
the rock cedars and other plants characteristic of the next forma-
tion. This association is also spread over the mesa west of the
river and over the lava field where the species are identical with
those of the sandy clay of the mesa, but some, especially Gutierrezia,
are stunted. Here also are a few cedars, Rhus, and other mountain
plants. This lava field seems to receive slightly more rainfall.
As one approaches the mountains and ascends one of the sand
or gravel fans at the mouths of the cafions, a new plant appears,
Fic. 2.—At the base of the Sandia Mountains: Opuntia arborescens society;
Rhus irifoliate appears in the center, and in the background on the rocky slope are
black looking clumps of Nolina.
Opuntia arborescens, whose cylindrical stems, 6-8 ft. tall, bear
beautiful deep rose blossoms in June, and yellow fruit the remainder
of the year (figs. 2 and 3). These cacti form dense thickets, which
with Yucca glauca, Croton texensis, and Fallugia, which again
become abundant here, are quite as characteristic features of these
fans as the more abundant Gutierrezia and grasses.
CEDAR FORMATION
Next comes the formation of which Juniperus monosperma is
the dominant plant. East of Albuquerque it is confined strictly
206 BOTANICAL GAZETTE [SEPTEMBER
to the mountains, but where the mesa rises higher (6500 ft. or over)
it stretches out over the plains. In the Estancia Valley it seems
to be spreading at the expense of the prairie, as considerable areas
are dotted over with young trees where there are no signs of old
ones. But in many places, as here, it clings to the rock outcrop
and to the neighborhood of scattered rocks, doubtless because of
the moisture conserved under them. In this connection it is
Fic. 3.—Opuntia arborescéns in fruit: to the left is an arroyo
interesting to recall the occasional occurrence of cedars on the lava
a thousand feet lower. That the lower edge of this formation is
limited by the supply of soil moisture is evident. On the whole,
it coincides quite closely with the lower limit of the usual winter
snow. Near the lower edge, especially, the trees are far apart,
broken, stunted, gnarled, constantly recalling an old neglected
orchard in a back pasture in Ohio. Gutierrezia and Yucca glauca
extend into this formation and Opuntia arborescens is abundant
1912] WATSON—PLANT GEOGRAPHY OF NEW MEXICO 207
and characteristic. Other members are Rhus trilobata, Nolina
lexana (a long-leaved liliaceous evergreen), and the spiny-leaved
oak, Quercus undulatus. The Rhus is also imperfectly evergreen,
and indeed there is less difference between the winter and the
summer aspect of this formation than of any other, because there
is less difference in the relative humidity of the soil.°
PINON FORMATION
This has been combined with the last by MERRIAM and other
writers, and they do shade into each other very gradually, even
imperceptibly, but no more so than do the Pinus ponderosa and
Douglas spruce formations, which are separated by these authors.
Furthermore, the pifion (Pinus edulis) never extends as far down
the mountain side as does the cedar, the differences being on the
average at least 500 ft. Other plants very characteristic here are
Yucca baccata or “amole,”’ mountain mahogany (Cercocarpus
parvifolius), Philadelphus microphyllus, Lesquerella Engelmanni,
and Tragia nepetaefolia.
YELLOW PINE ASSOCIATION
This is the ‘transition zone” of MERRIAM, which he states is
on the whole more closely related to the Sonoran than to the Boreal,
a conclusion which seems to the writer to be incorrect at least so
far as plants and insects are concerned. The latter are treated in
another publication.?7 The characteristic plants, after the Pinus
ponderosa scopulorum, are Geranium atropurpureum, white oaks,
red cedar (Juniperus scopulorum), the pasque flower (Anemone
patens Nuttalliana), wild gooseberry (Ribes divaricatum irriguum),
telea mollis, wild grape (Vitis arizonica), cudweed (Antennaria
plantaginifolia), and New Jersey tea (Ceanothus Fendleri). Here
occurs a sharp and complete change of flora. There is much more
difference between this formation (fig. 4) and the mesa or even the
pifion formation less than a mile away, than there is between it and
the woods of Ohio, as witness the preceding genera, if not species.
* Whether the oaks and Rhus drop their leaves early in the winter or carry them
until spring is determined by the soil moisture. In less dry winters and along arroyos
they retain them. Under more xerophytic circumstances the leaves are dropy
7 Report of the N.M. Resource and Conservation Commission. December 1ort.
208 BOTANICAL GAZETTE [SEPTEMBER
Here is a most interesting tension line between the flora of the arid
southwest and the more humid north.
The association descends in some places to 7000 {t., and extends
to the top of the range at 10,000 ft., and coincides very closely with
the region of deep winter snow. On the western slope its aspect
is somewhat different from that of the eastern slope. On the
Fic. 4.—View toward the south in the Sandia Mountains (about 8500 ft.) in
the yellow pine association: in the foreground the oak chaparral (Quercus sp. and
Robinia neo-mexicana) and yellow pine, and to left of center a Douglas spruce; in the
distance, covering a north-facing slope, is the Douglas spruce association.
former it reaches its best development in amphitheater-like
U-shaped valleys, which collect the winter snow and practically
protect the trees from the drying winds and sun of summer. These
areas I have called “pine parks.’’ On the east slope, with its
greater precipitation, the forests are more extensive and possess a
flora which reminds one very forcibly of that of the pine forests of
Kentucky, especially where there has been a fire. The dominant
1912] WATSON—PLANT GEOGRAPHY OF NEW MEXICO 209
grasses here, as there, are species of Andropogon, and mixed with
them are Liatris punctata, Ratibida columnaris pulcherrima, and
Zygadenus.
In places along streams charged with lime the red cedar often
takes almost entire possession of the soil, forming a quite distinct
association.
Fic. 5.—Top of Sandia Mountains: white oaks occupying a depression where
they are sheltered from wind.
In the Sandia Mountains the white oaks are very characteristic
of this formation, but in the more mesophytic Jemez Mountains,
and also on Mt. Taylor, where the yellow pine grows even more
luxuriantly, there is much less oak, and MERRIAM states that none
was seen on the San Francisco Mountains, although CowLes
reports its occurrence upon the southern slopes. The explanation
of this varying amount of pine and oak is to be found in the fact
that the oak is able to grow in more xerophytic situations than
the pine (fig. 5). It, with Robinia neo-mexicana and bearberry
210 BOTANICAL GAZETTE [SEPTEMBER
(Symphoricar pus rotundifolius), forms a dense and almost impene-
trable chaparral 4-5 ft. high, which covers the highest, steepest
slopes, and the wind-swept and therefore xerophytic mountain
tops. In these parts of the range there is very little pine or spruce,
except on north-facing slopes, and from a study of the Sandia
Mountains alone one would be tempted to place the oaks in a
separate formation; but there are clumps of oak among the pine
in all situations, and the study of other ranges would seem to indi-
cate that they belong to the same formation but that the oaks form
a more xerophytic association in this formation. Furthermore,
both the oaks and the locusts reach their maximum size only in
the more mesophytic places among the pines and spruces.
The herbs of this association are also somewhat different.
Conspicuous are several species of Pentstemon, Campanula rotundi-
folia, Ceanothus Fendleri, Thalictrum Fendleri, and somewhat less
common are Hedeoma Drummondit, Gentiana affinis, and Calochortus
Gunnisonit.
In the Manzano Mountains the alligator juniper is common in
what is chiefly the Pinus-Andropogon association, but having some
elements of the pifion formation. This would seem to be about
the northern limit of Juniperus pachyphloea, as it is entirely absent
from the Sandia Mountains.
Mountain meadows
In places (usually saddles) on the top of the range, the cha-.
parral gives place to a meadow-like growth, composed, however,
not chiefly of grasses, but of low herbs, Potentilla, Castilleja, Brickel-
lia, Chrysopsis villosa, A phanostephus humilis, Gymnolomia multi-
flora, Actinella acaulis, Achillea lanosa, Oxytropis Lamberti, Allium
stellatum, and cacti of the genera Mamillaria, Cereus, and Echi-
nocactus.
These open places are small, the largest being about a half-mile
long, and they occupy the less xerophytic situations. They are
sufficiently numerous to enable one to walk with comparative ease
along the summit of the range, dodging from one to another and
thus avoiding most of the chaparral:
1912] WATSON—PLANT GEOGRAPHY OF NEW MEXICO ait
DOUGLAS SPRUCE FORMATION
Covering north-facing slopes above 8000 ft. and extending down
the narrower cafions to about 7000 ft., we have a formation of
which the Douglas spruce (Pseudotsuga taxifolia) is the dominant
tree (fig. 6). This is the most mesophytic and dense of all our
forests. Here occur the blue and Canada violets, Berberis aqui-
folium (repens), Galium sp., Monarda fistulosa, Mertensia oblongi-
Fic. 6.—In the cafion the Douglas spruce association; on the rocky slope the
Pinus ponderosa association; in the foreground, white oaks, verbena (in bloom), and
mountain mahogany; a nal red cedar to the right of the rocks in the center
folia, Polemonium foliosissimum, Pachystima myrsinites, Oxalis
violacea, Prunus demissa., Fragaria, Rosa arkansana, Amelanchier
alnifolia, Heuchera parvifolia, Sedum Wrightii, Corydalis aurea,
Clematis (alpina) occidentalis, Aquilegia canadensis, Stellaria
Jamesii, and Smilacina stellata. This is the “Canadian zone”’ of
Merriam, but nowhere in this locality does it make a complete
belt around the mountains. It occurs in its full development only
in the most mesophytic places, as in the narrower V-shaped cafions
and on north-facing slopes where snow accumulates in huge drifts
212 BOTANICAL GAZETTE [SEPTEMBER
during the winter, but scattering trees, dwarfed and stunted, rise
from. the chaparral over most of the summits of the range mixed
with the yellow pine, especially at lower levels, and with the blue
spruce (Abies concolor) at higher. On North Sandia Mountain,
which, on account of its greater elevation and perhaps more east
and west trend, has a higher precipitation, the latter tree forms
almost pure forests. On the ground in its shade is a luxuriant and
in places an almost pure growth of Goodyera Menziesii.
Fic. 7.—Top of North Sandia Mountain: Picea Engelmannii; in the foreground,
Potentilla, ‘Casiillei, and A phanostephus.
On the very highest and most exposed part of North Mountain
the first are replaced by Engelmann’s spruce (fig. 7). This would
place it in Merrram’s “Hudsonian zone,” and it is so mapped.
On these heights one meets an occasional Pinus flexilis.
CANON ASSOCIATIONS
Ascending a cafion a very interesting succession of associations
presents itself. The first tree met approaching the mountains
from one of the arroyos is the hackberry (Celtis reticulata), usually
only a few scattered trees or a clump here and there. Next comes
1912] WATSON—PLANT GEOGRAPHY OF NEW MEXICO 213
a society dominated by box-elders, also rather scattered, and with
considerable grape (Vitis arizonica). These seem to be the cafion
representatives of the cedar and pifion formations respectively.
Higher up and in the narrower, more mesophytic portions of the
canon there occurs a society dominated by Populus angustifolia.
This corresponds with the pine formation on the whole, and if the
cafon is open or U-shaped, the yellow pine will occupy the floor
with the poplar along the stream. Ascending still higher, where
the cafion becomes decidedly V-shaped, the Douglas spruce forma-
tion holds full sway. And as one nears the head, above the per-
Manent stream there usually occurs an association of quaking
aspens, somewhat less mesophytic than the Douglas spruce for-
mation. In the shade of the aspens grow Rubus deliciosus, Osmor-
rhiza nuda, Saxifraga bronchialis, Jamesia americana, Delphinium
Scopulorum, Actaea spicata, Pedicularis procera, Frasera speciosa,
and nearly always young spruces. After a fire in the Douglas
spruce the quaking aspen always takes possession, but it has also
its natural place as a transition between the oak chaparral and the
Douglas spruce in the biotic succession.
The biotic succession in the Sandia Mountains is as follows:
the bare rock first incrusted with crustose lichens, then foliose
lichens, mosses, herbs, oaks, followed in some cases directly by
Douglas spruce and in others by aspen and then the spruce; and
then as physiographic succession comes in, the poplars, pines, and
box-elders in the cafion; and pine, pifion, and cedar on the slopes,
until the ultimate formation of the mesa is reached.
Response to climatic factors
This complex of associations is of course due to a complex of
Causes, of which the most important are relative humidity of the
air and more especially that of. the soil, and not the average tem-
perature of the growing or any other season, as some eminent
authorities have maintained. Temperature, of course, is a factor,
but principally as it affects the humidity. I have mentioned the
inability to grow certain cacti because of the winter’s cold. There
*A study of Mt. biped indicates that the alligator juniper has a place between
the yellow pine and the pifion
214 BOTANICAL GAZETTE [SEPTEMBER
are narrow Cafions in the lower parts of the mountains which would
doubtless be occupied by Douglas spruce were they situated at
a greater elevation, chiefly because of the greater precipitation.
On the other hand, most of the trees of the mountains are growing
on the campus of the University of New Mexico at an elevation
of only 5200 ft., but they are carefully irrigated, and the Douglas
spruces are in the shade of cottonwoods. The storksbill (Erodium
cicularium) grows in the mountain cafions and at an elevation of
5000 ft. in the valley. In the former situations it is in blossom
nearly all winter, often directly beside a snowbank, and doubtless
because of the snowbank, while those in the valley do not bloom
until the May or July rains.
Fallugia paradoxa is a most interesting plant in this regard.
As mentioned above, it is a very characteristic plant in the arroyos
of the mesa and its edge down to less than 5000 ft. It grows at a
lower altitude than this farther south, and doubtless would here
were there lower altitudes. Now these arroyos are the hottest
places in this region. Their sands reflect the desert sun’s glare
and the banks obstruct the breeze. Yet this same Fallugia forms
thickets on the Sandia Mountains at an elevation of over gooo ft.
on steep slopes facing the southwest, and it grows at all altitudes
between. Ona basis of temperature control, this distribution seems
inexplicable. But these arroyos are the least xerophytic places
on the mesa. The soil at the depth of a foot or two is always
moist, due to the fact that the arroyo brings down a flood of water
two or three times each summer and the sand conserves this and
the rain most thoroughly. On the contrary, those steep south-
western slopes are the most xerophytic places in the mountains,
with the exception of course of bare rock. But on account of
greater rainfall, these most xerophytic places of the mountains are
about as moist as the least xerophytic places on the mesa, and
Fallugia paradoxa occupies both situations.
On an ascent of the mountains made on May 8, 1910, the oaks
in the lower parts of the cafions were found in full leaf, and their
blossoms gone; a little higher they were just leaving out and
blossoming; at the top of the range not a bud had started. Again,
on October 6 the leaves were still green and vigorous at the base,
1g12] WATSON—PLANT GEOGRAPHY OF NEW MEXICO 215
but on the summit brown and frost-killed. Thus it is seen that the
growing season is at least a month shorter on the summit, but the
same oaks grow in both situations.
Another illustration of the influences of moisture is seen along
the Jemez River. This fair-sized stream comes roaring down off
the Jemez Plateau through a rather shallow cafion which faces the
south. This (altitude 6000-7000 ft.) is occupied by the Douglas
spruce formation, but the slopes on each side are occupied by
pifion, the yellow pine being largely omitted. The branches of
the spruce and pifion are in places at the same level and subject
to the same hot sun and consequently the same temperature, but
the roots of the Douglas spruces have access to the unfailing water
supply of the stream.
This tendency of the “Canadian zone” to creep down the cafions
and of the Sonoran to ascend the ridges is noted by MERRIAM, but
is explained as due to warm and cool winds, vertical exposure to
the sun, etc. It receives a much simpler explanation in that the
ridges are more xerophytic than the cafions. At night, when a
plant is supposed to make a goodly share of its growth, these ridges
are little if any warmer than the adjacent cafions. They are sub-
ject to greater and more sudden changes of temperature, to drying
winds, and are less able to hold their moisture—they are more
xero phytic9
In most situations in the Sandia Mountains the oaks of the
transition zone entirely surround the colonies of the Douglas spruce
(Canadian zone). In watching the Sandia Mountains during four
winters I have been struck by the very close correlation between
the lower limit of the average winter heavy snow and that of the
lower limit of the yellow pine. I believe that it is chiefly these
Snows that determine the distribution of this tree. Far be it from
me to maintain that the temperature has no effect on the plants of
this region. I am simply contending that in this arid region, at
least, water is more important. Any scheme for mapping “life
zones” should be based on all the factors determining the same and
hot on one alone.
* This same tendency is seen in the Rio Grande Valley, where occur many eastern
and northern genera and even species (as Aster, Solidago, Cassia, etc.) which are
absent from the higher but drier mesa.
216 BOTANICAL GAZETTE [SEPTEMBER
Light also is of course a factor even with the plants of the mesa.
I tried to grow some Yucca and Fallugia in the slight shade of
some box-elder trees, but they all died. It is probable that light
is quite as important indirectly through its acceleration of tran-
spiration as directly through its relation to photosynthesis.
Furthermore, these different factors may be of a very diverse
importance in different groups. What may be an effective barrier
for one form of life may have little influence on others. The sum
total of heat during the season of reproduction may well be more
of a barrier to mammals than to plants. BANxs has remarked
in a recent publication that it would seem to be necessary to have
a different arrangement of zones for at least every family of insects.
Summary
1. In North Central New Mexico the arid climate of the south-
west meets (in the mountains) the more humid one of the north
and east.
2. Corresponding with this abrupt change of climate there is
an abrupt change of plant life.
3. The genera and some of the species of the mountains are
identical with those of the east; those of the mesa are entirely
different. There is a greater difference between the flora of the
yellow pine association and that of the mesa, less than a mile away,
than between the former and Ohio and probably even Europe or
Japan.
4. The chief factor determining this change is moisture, the
supply of which is largely determined by precipitation, ability to
hold it, and protection from drying winds and sun, as shown by the
following facts:
a) The same plants (Fallugia, Erodium, oaks) occur throughout
a great range of altitude and temperature, but in soil of about the
same degree of humidity.
b) Spruces and pifions will grow with their branches almost
touching if the roots of the former have access to an unfailing
water supply.
c) Aspring will change “ Upper Sonoran’”’ to ‘‘ Lower Sonoran.”
1912] WATSON—PLANT GEOGRAPHY OF NEW MEXICO 217
d) Plants as Erodium or Draba bloom much earlier in the cooler
but moister mountains than on the warm but arid plain.
e) A patch of mesophytic spruces (“Canadian zone’’) is very
frequently entirely surrounded by the more xerophytic oaks of the
“Transition zone.”
f) The tendency of the higher zones to creep down the cafions
and of the lower zones to creep up the ridges receives a much more
plausible explanation in connection with the supply of moisture
in the two situations, than through the cooling effects of descend-
ing currents and the warming effects of ascending ones.
5. An arrangement of “‘zones”’ should be based on all factors
determining the distribution of life and not on one only, especially
in a region where that one is of secondary importance.
6. Most of the plants of the mesa do not show the marked
seasonal periodicity of the east.
7. Plants having large organs for the storage of moisture do
show seasonal periodicity.
8. A characteristic of much of the vegetation is the ability to
lie dormant until the rains come, and then to make an eer
rapid growth and reproduction.
9. The differences in amount and distribution of rainfall in
different years causes a moré marked response in plants (shown by -
height and reproductive activities) than in more humid regions.
10. The region is a particularly good one in which to study
physiographic plant ecology’ because of the abrupt differences in
physiography and climate.
University or New Mexico
ALBUQUERQUE
THE PERFECT STAGE OF ACTINONEMA ROSAE*
FREDERICR A. WOLF
(WITH PLATE XIII)
Perhaps no plant disease has been more widely observed or
is more generally known, both in Europe and the United States,
than the black spot of roses caused by the parasitic fungus Acti-
nonema rosae (Lib.) Fries. The spots, which are more or less
circular in outline, are characterized by a very irregular, fibrillose
border. This fibrillose character is due to the radiating strands
of mycelium which occur beneath the cuticle. Appearing among
the mycelial strands are numerous dark specks, the fruit bodies
of the fungus. The spots may be isolated and confluent, or so
numerous as to involve the entire upper surface of the leaf. Plants
which are attacked become defoliated early in the season, and the
leaf buds, which should remain dormant till the next year, often
open late in the season. As a result, the plant is weakened so that
it blossoms poorly or not at all in the following season.
Since very little is known concerning the life history of the
- fungus and the development of the Actinonema stage, an attempt
has been made by cultures on artificial media and on the host to
furnish a more satisfactory knowledge of this interesting organism.
Before giving an account of this study it may be well to state
briefly the characters of the vegetative and fruiting structures of
the rose Actinonema.
The vegetative body of the fungus consists of two parts, the
subcuticular mycelium and the internal mycelium. The subd-
cuticular mycelium is immediately underneath the cuticle, being
above the outer wall of the epidermal cells. It consists of branched,
radiating strands of mycelium which anastomose, making a net-
work. Each strand consists of several filaments united together,
either side by side or sometimes superimposed. At the right of
the acervulus in fig. 1 is shown a cross-section of one of these
strands. The internal mycelium penetrates the mesophyll of the
« Contribution from the Department of Botany, Cornell University. No. 143-
Botanical Gazette, vol. 54] [218
1912] WOLF—ACTINONEMA ROSAE 219
leaf and furnishes nutriment for the subcuticular part. It is
connected with the latter by occasional hyphae which penetrate
the epidermal cells or pass between them.
A section of the fruit bodies or acervuli perpendicular to the
surface of the leaf shows that they are formed between the cuticle
and the outer wall of the epidermal cells. They are consequently
flattened. The stroma of the acervulus is seated directly on the
epidermal cells and consists of a very thin layer of small, hyaline
to yellowish, pseudoparenchymatous cells. It is connected with
the internal mycelium below by hyphae which extend either through
or between the epidermal cells into the mesophyll. Laterally the
stroma is connected with the subcuticular mycelium. There is no
wall or membrane of fungous tissue covering the acervulus. On
the upper side of this stroma certain cells are formed which bear
the conidia. These conidiophores are not prominently differen-
tiated in form from the other stromatic cells, but are slightly
elongated upward. The conidia are hyaline, 2-celled, and oval
to elliptical in outline. They are usually somewhat constricted
at the septum. The conidia are formed on the somewhat pointed
upper ends of the conidiophore layer. The great numbers which
are produced cause such a pressure that the cuticle is finally rup-
tured. The cuticle, which is the only covering for the acervulus,
is thus thrown back irregularly, exposing the mass of conidia and
permitting their escape.
While the spots together with the mycelial strands and acervuli
appear dark, this color is not due to the fungus, which is almost
colorless, but to the disintegration of the cells below the spot.
Development of acervuli
It is from the subcuticular mycelium that the acervuli arise.
At certain definite points the mycelium begins to form a stroma,
which increases in a centrifugal manner, forming a more or less
circular stromatic layer. Certain cells of this stroma which are
to give rise to the conidia are directed upward as short stalks.
These increase in size, forming a closely aggregated layer standing
Perpendicular to the stroma. Meanwhile, the mesophyll tissue
directly below the acervulus is being disintegrated and a dense
220 BOTANICAL GAZETTE [SEPTEMBER
tangle of fungous filaments is formed in its place. From the per-
pendicular cells arising from the stroma a cell is cut off by a trans-
verse septum. This cell enlarges into an oval body, the conidium,
which soon becomes septate. As the conidia are increasing in
size, the pressure on the cuticle above becomes greater and greater,
so that it is at length broken, leaving the margin of the exposed
acervulus irregularly torn (fig. 1). Sometimes a central papilla
is present which marks the place where the cuticle will rupture.
At maturity the conidia are oval to elliptical and 2-celled. They
are hyaline and 18-25xX5-6. They may be unequally septate,
either straight or subfalcate, and often so deeply constricted at
the line of septation that the halves fall apart readily. Several
large granules and guttulae are normally present (fig. 3).
Germination of conidia
The conidia germinate within 24 hours in bean agar or in hang-
ing drops of water. Each of the cells may first enlarge, becoming
more or less spherical and vacuolate before the formation of the
germ tube. Frequently only one of the cells germinates by the
formation of one or two germ tubes (fig. 3). No formation of
colonies was secured in poured plates of bean agar, although the
fungus grows slowly when the conidia are planted on the surface,
forming a small, prostrate, tawny colony. Apparently growth
ceases as soon as the reserve food material within the conidium
has been utilized in the development of the short hypha. This
seems to occur when the hypha is 10-20 times the length of the
conidium and may have become branched with several septa.
If such conidia are cut out with as little of the surrounding medium
as possible and transferred to bean pods, using ordinary sanitary
precautions, and if the medium is spread out so as to bring the
germinating conidium in contact with the pod, further growth
may be induced. In two or three weeks small colonies are form
At first the mycelium is whitish, changing to a pinkish color and
becoming pale brown to blackish with age. The colonies do not
spread out on bean pods, but form knots of fungous tissue often
one-half as high as the diameter of the colony. The tissue of the
bean which is attacked becomes blackened in a fibrillose manner,
1912] WOLF—ACTINONEMA ROSAE 221
simulating the blotch on the leaves. Conidia are formed readily
on the ends of the hyphae. Such conidia are often so strongly
constricted at the septum that each cell is round. There is, then,
little surface of contact between the cells and they are readily
separable one from the other. These spherical halves germinate
in the normal manner (fig. 2). Acervuli apparently like those on
the leaves are also formed on bean pods in the blackened areas.
These bear conidia like the typical ones from rose leaves.
Systematic position of the conidial stage
The genus Actinonema is usually placed by systematists in
the Sphaeroidaceae.2 This family is a group of imperfect fungi
possessing a pycnidium of the type present in Ascochyta, Sphaerop-
sis, etc. The pycnidium or conceptacle is more or less oval in form,
with a membranaceous wall of fungous tissue, usually opening at
the apex by a minute pore. Some writers speak of the fruit bodies
of Actinonema as pycnidia’ or perithecia.’ FRANK’ considered
them as very flat spermagonia (‘des sehr flachen Spermagoniums”’).
SORAUER’ speaks of them as small astomate pycnidia (‘die kleinen
miindungslosen Pykniden”’).
It is very evident from the foregoing account that the conidial
Stage of the rose Actinonema is not of the type in which the conidia
are borne in a pycnidium or perithecium. The conidia are borne
in an acervulus resembling that found in the Melanconiales, as
exampled by Gloeos porium, Marsonia, etc. SCRIBNER’ has correctly
figured the structure of the acervulus and says that while the
fungus from analogy is placed with the sphaeriaceous fungi, no
perithecia-like or pycnidial structures have been observed.
Partly because of the different interpretations of the morphology
; *Saccarpo, P. A., Syll. Fung. 3:408. 1884; also Linpav, G., Sphaeropsidales
in ENGLER and-Prantt’s Pflanzfam. 12369. 1900
> Linpav, G., loc. cit.
* Masseg, G., Diseases of cultivated plants. 428. 1910.
* Frank, A. B., Die Krankheiten der Pflanzen. 621. 1880.
*Soraver, Paut, Handbuch der Pflanzenkrankheiten. 406. 1908.
*Scripyer, F. L., The black spot on rose leaves. Rept. U.S. Dept. Agric.
~ 366-369. pis. 8, 9. (1887) 1888.
227 BOTANICAL GAZETTE [SEPTEMBER
of this fungus it has been variously named by different workers.
In 1849 the name Actinonema rosae (Lib.) Fr.’ was employed.
In 1853 BONORDEN? described it as Dicoccum rosae, one of the
Hyphomycetes. He says that the fungus forms small, closely
aggregated pustules of a brown green color which dehisce irregu-
larly. From collections made in 1888-1889, BRriosI and CAVARA
distributed the species under the name Marsonia rosae (Bon.)
Br. & Cav." because they recognized the acervulus type of fruit
body which is characteristic of the Melanconiales. The 2-celled
hyaline conidia suggested its position in the genus Marsonia.™
I have been able to examine the specimens distributed by BRiostI
and CAvaRA and have found them to be the same as the rose
Actinonema in the United States. The drawing of acervulus and
spores which accompany the specimens show the same structure.”
SACCARDO™ notes that Marsonia rosae (Bon.) Br. and Cav.
resembles Actinonema rosae (Lib.) Fr. This same fungus was
described by Trait" in 1889 as occurring on roses in Scotland:
He called it Marsonia rosae.
The characters of the genus Actinonema have changed from time
to time since the genus was established by Persoon. He applied
the name to those forms on leaves and stems having radiate sterile
mycelial strands. He describes two species, A. crataegi and A.
caulincola, in neither of which perithecia or conidia were observed.
In 1828, Fries” included two species in the genus Actinonema,
8 Frres, Extras, Summa veg. Scand. 424. 1849.
9 BoNoRDEN, H. F., Beitrige zur Mykologie. Bot. Zeit. 282. pl. 7. fig. 2. 1853-
» Briost and Cavara, Funghi parassiti delle coltivate od utile. n. 97. 1889.
™mLa natura degli acervuli fruitifera, sorrane ed erompenti, ci induce a
riferire questo funghetto ai Melanconiei sezione delle Didymosporee Sacc. ove trova
riscontro nel genere Marsonia pure a spore didime e jaline.
2 Type material was received through the courtesy of the Bureau of Plant Indus-
try, U.S. Dept. Agric. I am greatly indebted to Miss Erne C. Fretp of the same
Bureau for some notes on the specimens. She finds that there is no apparent differ-
ence between Marsonia rosae of this collection and other European material which is
labeled Actinonema rosae
13 Saccarpo, P. A., Syll. Fung. 10:477. 1892
™ TRAIL, J. W. H., Micromycetes of ivweay 46. 1880.
5 Persoon, C. H., Mycologia Europaea 1:51-52. 1822.
© Fries, Exias, Elenchus Fungorum. 151. 1828.
1912] WOLF—ACTINONEMA ROSAE 223
A. padi and A. crataegi, the latter showing at length perithecia-
like structures, but no conidia were observed. In 1829"? he employed
the name Actinonema for the sterile state of fungi belonging to the
Pyrenomycetes and Perisporiaceae. Later™ he characterized the
genus as having a fibrillose, radiating mycelium, a delicate peri-
thecium, and bilocular spores, and lists A. rosae as one of the
species which often possesses only a sterile mycelium. SACCARDO”
employs these characters as given by Fries and notes that the
fruits have not been observed in many species. Of the 18 species
of Actinonema which have been described, there are 8 species in
which the spores were not observed at that time. The radiating
fibrillose character of the mycelium has been used as the principal
generic character for these species, thus employing the distinctive
character as originally given by PeRsoon. Linpav” includes in
Actinonema astomate pycnidial forms occurring on leaves. The
pycnidia arise from radiately actinic strands of mycelium.
The genus Marsonia is characterized by having a subepidermal
acervulus, in which are produced hyaline, 2-celled conidia, very
similar to the conidia of Actinonema. Several species of Marsonia
have been described, however, in which the acervulus is swbcuta-
neous, as Marsonia baptisiae E. & E., M. panatoniana Berl., and
M. fructigena (Rick.) Berl. Brriost and CavarA recognized the
true morphology of the rose Actinonema acervulus, but attached
no significance to the fact that it was subcuticular and not subepider-
mal. The Actinonema-like character of the mycelium was not
taken into account by them as indicative of generic position.
TRar must have been of the same opinion when he named this
same fungus Marsonia rosae.
Even though the subepidermal acervulus has been made one
of the generic characters of M. arsonia, it would seem that these
subcuticular forms might properly be placed in this genus. On
the other hand, we do not know the structure of the perithecia or
Pycnidia of other species of Actinonema. If we accept PERSOON’S
‘’ Fries, Extas, Systema Mycologicum 3:266. 1820.
. , Summa veg. Scand. 424. 1849.
*? Saccarpo, P, A., Syll. Fung. 3:408. 1884.
* Linpav, G., ENGLER and PRant1’s Pflanziam. 1:399. 1899.
234° BOTANICAL GAZETTE [SEPTEMBER
characterization of the genus, it has no fruit bodies, but consists
only of sterile mycelium.
The rose fungus evidently, then, does not possess the characters
of a typical Marsonia, nor does it agree with the original charac-
terization of Actinonema. Whether these differences are worthy of
good generic rank, separating it from both these genera, is a
matter for consideration.
Development of the ascigerous stage
During the autumn of 1910, leaves attacked by the conidial
stage were collected and placed in wire cages to winter out of
doors. When some of these leaves were brought to the laboratory
early in April and examined, shield-shaped structures suggestive
of the perithecia of the Microthyriaceae were found to be present.
At this time, however, no spores had been developed. Fig. 2
shows one of these perithecia as seen in surface view. Such prepa-
rations were made by stripping off the epidermis of the leaf together
with the perithecia. By April 27 these perithecia had matured
and were found to possess characters similar to the genus Asterella,
a genus apparently including heterogeneous elements.
For the study of the development of the perithecia, material
was killed in Merkel’s fluid and stained with Flemming’s triple
‘stain. By killing material at different times during a period of
three weeks, many of the developmental stages were obtained.
Not all perithecia on the same leaf are in the same stage of develop-
ment at the same time. Unfortunately the material was too far
advanced for the study of fertilization and the immediate subse-
quent development. This in itself would be a very interesting
study, since nothing is known of these phenomena in the Micro-
thyriaceae.
The shield was found to be entirely separate in origin from
the tissue which gives rise to the asci. It is formed immediately
beneath the cuticle from the radiating strands of mycelium which
now are thick-walled and dark brown in color. ‘The strands
themselves can be traced across the shield (fig. 4), showing that
the growth begins at any point on the mycelial strand and new
cells are added in a centrifugal manner. In this way a more OF
1912] WOLF—ACTINONEMA ROSAE 225
less circular shield is formed, the elements of which are arranged
in a radiating manner, especially noticeable at the margin of the
shield. The cells which make up the shield possess thick, dark
walls.
The shield varies in diameter from 100 to 250“, and may be
more than one cell in thickness. In fig. 6 is shown a young stage
in the development of a perithecium. The shield forms a thin
layer above the epidermal cells or beneath the elevated cuticle.
Beneath the epidermal cells, and above the palisade parenchyma,
is an undifferentiated layer of fungous tissue, the stroma from
which the asci later arise. This stroma is 3-6 cells in thickness
and is made up of cells similar to those of the shield. Occasional
filaments connect these two layers through the epidermal cells
of the host. In fig. 7, when the fertile layer has increased and
the fruit body has begun to be differentiated, the shield is still
distinct and not connected with it at the margin. At this time
the cells in the center of the young fertile stroma are thinner walled,
with a more deeply staining content.
The asci are formed within the fertile stroma, arising from the
basal portion, as shown in figs. 8 and 9. In this way the cells in
the upper part of the fertile stroma persist, forming a delicate
covering over the hymenium. The development of the asci
within this fertile stroma is comparable with their origin in the
apothecia of the Phacidiales. The hymenium arises in the same
way, and the upper part of the stroma corresponds with the tissue
which covers the hymenium before the opening of the apothecium.
In the rose fungus, however, this covering is not so well developed
and may not always persist to be folded back when the fruit body
opens. It may form a continuous delicate layer over the asci
until the fruit body is mature and only rupture together with the
shield. In other cases this covering is broken by the develop-
ment of the hymenial layer. Fragments may remain at the margin
of the apothecium or they may disappear. It is only by the elonga-
tion of the asci and the consequent increase of pressure that the
cuticle and shield, together with the upper part of the apothecium,
are ruptured in an irregularly stellate manner and thrown back.
he portions covering the hymenium have ruptured in fig. 11.
226 BOTANICAL GAZETTE [SEPTEMBER
In the mature opened condition shown in fig. 12, the thin-walled
_ cells of the upper part of the apothecium still persist on the margin
of the fruit body. The opened perithecia present in surface view
the appearance shown in fig. 5. The folding back of the shield
is shown in section in fig. 15. The perithecia develop independently
of the acervuli, as would be expected from the origin of the two.
In fig. 13 is shown an old acervulus by the side of a perithecium.
In none of the material which had wintered could acervuli be found
which were bearing conidia.
The epidermal cells of the host persist for a long time, so that
the ascogenous layer and shield are separated. They may become
entirely destroyed as the asci elongate and the perithecium becomes
mature (fig. 14), or they may persist on the margin of the mature
perithecium (fig. 12). The perithecia vary in shape from spherical
to discoid. One of the large discoid perithecia is represented in
section in fig. 14. The septate, knobbed paraphyses extend
between and beyond the asci until the time when the spores are
nearly mature. Asci in many stages of development occur within
each perithecium. Mature asci extend slightly beyond the para-
physes and the spores are discharged from an apical pore (fig. 16)
formed by the rupture of the wall. The asci are oblong or subcla-
vate, tapering above rather bluntly, and are 7o-80X15 b.
Apparently the spores are not discharged with violence. Agar
plates were inverted above rose leaves in moist chambers, the
surface of the agar coming nearly in contact with the leaf. No
spores were observed to have lodged on the surface of the agar,
as would be expected if they were projected forcibly from the
ascus. As far as I have been able to observe, they merely pile
up in a whitish heap in the opened perithecium. The spores
are 20-25X5-6m, varying extremely in form (fig. 17), as do the
conidia. They resemble the conidia very much except that they
are not so strongly constricted at the septum. They are hy aline
and bicellular. Usually large granules and several guttulae are
present in each cell. The cells are generally unequal in size, the
upper one being broader.
1912] WOLF—ACTINONEMA ROSAE 227
Germination of ascospores
Considerable difficulty was experienced in germinating the
ascospores. All attempts to employ artificial”°media have been
unsuccessful. Spores from the same preparation have been used
in poured and planted plates of bean agar, in hanging drops of
water, in similar drops in which has been placed a small piece of
green rose leaf, in infusions made by boiling green rose leaves in
water, amd in drops of water on rose leaves in a moist chamber.
In no case has germination been secured in any other way than by
the last method. Germination occurs within 24 hours, the larger
cell more often germinating, although either cell is capable of
germination. A germ tube is characteristically formed at one
side near the end of the spore. This hypha soon branches and
septa are laid down (fig. 18). Occasionally two tubes are formed
from a single cell. In about 35 transfers of spores to bean pods
made under aseptic conditions no growth was secured. From
these and the foregoing experiments it would seem that the asco-
spores are dependent on some stimulus of the living plant for
germination. There may be some advantage to the parasite in
this, since many spores would germinate before they are able to
reach a suitable location on the host.
Artificial infection
Ascospores were used in the infection experiments. Since they
are discharged in such masses in the opened perithecia, they can
easily be removed free of everything else. Several series of poured
plates made from spores obtained in this way remained absolutely
sterile, which indicated that no other spores except ascospores of
the rose fungus had been carried over. The spore masses were
first removed to a drop of sterile water on a slide. With a needle,
then, some of the spores were transferred to drops of water on the
leaves of living roses. The plants were then covered with bell-
Jars and were allowed to remain covered for two days. Infec-
tons from inoculations made April 27 were very evident by May 7,
appearing as small black areas. By May 15 mature acervuli and
conidia of the Actinonema type were formed, thus completing
the life cycle and connecting the two forms. Inoculations were
228 BOTANICAL GAZETTE [SEPTEMBER
also made in the same way on leaves placed in Petri dishes lined
with moist filter paper. In four days the radiating strands were
very evident with the aid of the low power of a microscope. Infec-
tion occurs by the entrance of the germ tube through the cuticle,
there being no stomata on the upper surface of the leaves. From
the subcuticular mycelium, hyphae later penetrate to the tissue
below, first filling the epidermal cells, and only in the advanced
stages of the disease penetrating the mesophyll.
The way in which this fungus hibernates is no longer a matter
of conjecture. ScRIBNER™ suggested that the spores lodge on the
buds in autumn and remain there dormant until the leaves have
expanded the following summer. As has been found to be true
with many imperfect fungi, this fungus is carried through the
winter on fallen leaves and the ascosporic stage develops in the
following spring.
This study shows that Gnomoniella rosae (Fkl.) Sacc. is
not the perfect stage of the rose Actinonema, as has recently
been suggested.” One species of Actinonema, however, has been
connected with an Asterella, Actinonema rubi (Fkl.) becoming
Asterella rubi (Fkl.) v. Héhnel.3 He found in the spring the
Asterella stage on living canes of Rubus Idaeus. These areas had
been occupied the previous summer by the conidial stage.
The genus Asterella was first proposed by SACCARDO”™ as a
subgenus of Asterina for those species which have hyaline spores.
Later 5 he raised Asterella to generic rank. As Saccarpo himself
points out, further investigation of species which are at present
placed in the genus Asterella will result in their transfer to Asterina,
since the spores become brown at maturity. Lrypav* thinks the
existence of this genus is still questionable. Subsequently but
little investigation has been made on the genus and no clear-cut
2t See footnote 7.
2 Laupert, R., and Scnwartz, Martin, Rosenkrankheiten und Rosenfeinde.
16-19. IQIO.
Von Hoéunet, F., Uber Actinonema rubi Fuckel ist Asterella rubi (Fkl.) v-
Hohnel. Ann. Myc. 32326. 1905
44 Saccarpo, P. A., Syll. Fung. 92393. 1891.
25 — , Syll. Fung. 1:25 and 42. 1882.
26 LINDAU, G., ENGLER and Prantt’s Pflanzfam. 1: 340. 1897.
1912] WOLF—ACTINONEMA ROSAE 220
generic limits have been proposed. One finds included species
whose spores become brown, some which are aparaphysate, some
possessing filiform paraphyses, and others having paraphyses
which are enlarged at the tips. In fact, the whole family Micro-
thyriaceae is but little known, due in part to the fact that most
of the forms are tropical. A thorough investigation of perithecial
development is necessary, since very little attention has been
given to this group. The family is at present characterized by
having perithecia which are shield-shaped, thin membranaceous,
flat, with a rounded pore.at the top and with a membrane formed
only on the upper side. With the exception of the species on rose
leaves, which I have studied, it is not known whether or not the
forms without an apical pore’ possess one at maturity. It has
long been recognized, because of the entirely different manner of
development, that the Microthyriaceae are widely separated from
the other two families of the Perisporiales, the Erysiphaceae and
the Perisporiaceae.
In order to see if other genera of the Microthyriaceae corre-
sponded in structure and development with the forms on rose
leaves several of them were examined. Asterina orbicularis B. &
C., n. 231 of RAVENEL’s collections, forms entirely superficial
perithécia, sending hyphae partially through the cuticle. Asterina
inquinans E. & E., n. 1785 N.A.F., is also superficial, ends of
the mycelium being observed in the stomata. Asterina plantaginis
Ellis, n. 791 N.A.F., forms spherical perithecia entirely sunken
within the host tissue. The perithecia are ostiolate and appear
to have the characters of a S phaerella. Micropeltis longispora
Earle, n. 6349, plants of Porto Rico, is entirely superficial. Micro-
thyrium littigioswm Sacc., collected at Frankfort, Germany, by
Dr. Paut MAGNUS, seems to form superficial perithecia, but the
mycelium is present in the epidermal cells. Mvyriocopron smilacis
(De Not.) Sacc., n. 600 E. & E., N.A.F., also forms superficial
perithecia and the mycelium occurs in the stomata. None of
these representative genera seem to be comparable to the type
of development as exhibited by the rose fungus. Since se little is
known of the perithecial development and the method of securing
food supply of the Microthyriaceae, this family would afford an
230 BOTANICAL GAZETTE [SEPTEMBER
excellent field for investigation. MAaArrReE” has described the organs
of absorption of Asterina usterii and Asterina typhospora. A
slender filament penetrates the epidermal wall and when it has
reached the cavity of the cell it enlarges and becomes profusely
branched.
The opened perithecia of the rose fungus present characters
indicative of a close relationship to the Phacidiales. The ragged
margin of the shield suggests the ruptured outer portion of the
wall of the fruit body which at first covers the hymenium. The
presence of knobbed paraphyses is also a character possessed by
many Discomycetes. In the Phacidiales, however, as far as can
be learned, the upper or outer part of the fruit body is not separate
in origin from the ascogenous stroma, nor does it possess the
characteristic structure, of the shield present in the Microthy-
riaceae. On the other hand, it is quite probable that few of the
Microthyriaceae possess a stroma within the leaf tissue as has been
described for the fungus in question. The majority are apparently
superficial and with a well developed wall or shield only on the
upper side. In spite of these facts, I feel that this fungus should
be placed in the Microthyriaceae. Further morphological study
of other species of this genus and related genera will throw some
light on the relationship of these microthyriaceous forms. Perhaps
the systematic position of many of these forms will be changed
as soon as the species have been satisfactorily investigated. While
the possession of the shield and the hyaline 2-celled spores are
characteristics which would suggest the position of the rose fungus
in the genus Asterella, yet, as has been pointed out, this genus is
not clearly limited and contains heterogeneous elements. This
fungus does not seem to accord morphologically with the members
of this genus in the sense in which the genus was first employed:
Species representing several generic types apparently have been
included in Asterella. Since the characters presented by this
fungus are evidently those of a distinct generic type, rather than
place it in the genus Asterella, it seems better to treat it as the type
of anew genus. Because of the two separate structures, the shield
27 Marre, R., Les Sucoirs des . et des Asterina. Ann. Myc. 6:124-128-
fig. 4. 1908.
1912] WOLF—ACTINONEMA ROSAE 231
and apothecium, the name Diflocarpon* is proposed. The follow-
ing description of the genus is given.
Diplocarpon, nov. gen.—Fruit bodies formed in connection
with an extensive subcuticular mycelium, consisting of a sub-
cuticular circular shield with more or less radiate elements espe-
cially at the margin, and an innate apothecium. Shield, together
with the radiating strands on which it is formed, dark brown,
without a central pore. Apothecium at first separate from the
shield, only joined here and there by hyphae which pass between
the epidermal cells. Apothecium joined with the margin of the
shield at maturity. Hymenium covered by the shield and upper
part of the apothecium which at maturity rupture in an irregularly
stellate manner. Asci oblong to subclavate, 8-spored; paraphyses
unbranched; spores elongated, 2-celled, hyaline at maturity.
A conidial stage of the Actinonema-type occurs in one species.
Peritheciis scutulum subcutaneum et apothecium innatum constitutis;
scutulo mycelio subcutaneo, lato extenso, atro-brunneolo insidiente; margine
radialiter diffuso, contextu membraneo, astomate; apothecio innato, primo
scutulo separato, maturitate margine adjuncto. Peritheciis centro stellatim
laciniato-dehiscentibus; ascis oblongis; paraphysibus simplicibus; sporidiis
oblongo-ellipticis, bicellularibus, maturitate hyalinis.
Actinonema uni speciei cujus statum conidicum sistit.
Since this study connects for the first time the ascosporic stage
with the conidial stage of the black spot of rose leaves, a brief
characterization of the species is added:
Diplocarpon rosae, n.n.
Syn. Erysiphe radiosum Fr. Observationes Mycologicae. 207. 1824.
Asteroma rosae Lib. Mem. Soc. Linn. 5:404-406. 1827. Acti-
nonema rosae Fr. Summa. veg. Scand. 424. 1849. Dicoccum rosae
Bon. Bot. Zeit. 282. 1853. Marsonia rosae Trail. Fung. Inverar.
46. 1889. Marsonia rosae Br. and Cav. Funghi parassiti n. 97.
1889.
Ascigerous stage.—Perithecia epiphyllous, spherical to disciform,
TOo-250 # in diameter; upper part or shield dark brown, subcuticu-
lar, formed in conjunction with the radiating strands of mycelium,
circular, with a more or less radiating structure toward the margin.
Lower part of fruit body disciform, subepidermal, of several layers
of Pseudoparenchyma cells, the outer of which are dark brown,
28 derdéos, “double,” xapmés, “fruit.”
232 BOTANICAL GAZETTE [SEPTEMBER
the margin at length breaking through the epidermis and here and
there becoming connected with the margin of the shield. Fruit
bodies closed at first, later opening by the rupturing of the shield
together with the upper part of the apothecium in an irregularly
stellate manner from the center. Asci oblong or subclavate,
narrowed abruptly above, 7o-80X15, 8-spored; paraphyses
slender, enlarged abruptly at the tip, often 1-septate. Spores
oblong-elliptical, hyaline, unequally 2-celled, constricted at the
septum, 20-25 5-6; upper cell somewhat larger, cells usually
guttulate.
Conidial stage.—Spots epiphyllous, large, dark brown or blackish,
with an irregular radiating border, when numerous becoming
confluent and sometimes involving the entire leaf. Mycelial
strands composed of several filaments, at first hyaline, forming a
subcuticular network. Internal mycelium connected through the
epidermis with subcuticular mycelium. Acervuli subcutaneous,
covered at first by the cuticle which ruptures irregularly; conidia
2-celled, often deeply constricted, straight or subfalcate, 18-25%
5-6 #, hyaline and guttulate.
Conidial stage appearing on rose leaves in summer and autumn often
causing defoliation of the plants. Ascigerous stage appearing in the spring
on fallen leaves which have remained on the ground.
Peritheciis epiphyllis, globosis v. disciformibus, 100-250 p diam. ; scutulo
atro-brunneolo, subcutaneo, mycelio reticulato insidiente, orbiculare, margine
plus minusve radioso. Apothecio primo epidermide tecto, demum margine
scutuli adjuncto, in centro irregulari-stellato dehiscente. Ascis oblongis vel
subclavatis, supra obtuse angustatis, 70-8015 m, octosporis; paraphysibus
filiformibus, apice incrassatis, interdum 1-septatis; sporidiis oblongo-ellipticis,
inaequaliter bicellularibus, ad septa constrictis, guttulatis, hyalinis, 20-25 5~
6
Hab. in foliis dejectis Rosae sp. :
Status conidicus: Maculis epiphyllis, atro-brunneis vel purpurascentibus,
fibrillis € centro radiantibus, albido-arachnoideis; acervulis subcutanels,
sparsis, nigricantibus; conidiis constricto, 1-septatis, guttulatis, hyalinis,
18-25 X 5-6 p.
Hab. in foliis vivis Rosae sp.
Susceptibility of the host
This disease occurs on nearly all the cultivated varieties of
roses both out of doors and in the greenhouse. Briosi and
CavaRA note that only four varieties, Rosa hybrida vat. Belle
1912] WOLF—ACTINONEMA ROSAE 233
Angevine, Triomphe d’Alengon, Abel Grant, Rosa borboniaria
var. Triomphe d’Anger, of the 600 growing in the botanical
gardens at Pavia are free from the attacks of this fungus. LAUBERT
and SCHWARTz” call attention to the fact that the bushy sorts are
more susceptible than climbing varieties, and also that thin-
leaved species are most liable to attack. HatsTep*® finds that a
wild species, Rosa humilis, is also subject to attack when growing
in a garden with diseased plants. The amount of loss caused is
equaled or surpassed by only one other rose disease, the powdery —
mildew. :
Control measures
This disease has been very satisfactorily controlled by the use of
any of the standard copper compounds. Since now we know that
the fungus winters over in the fallen leaves, sanitary measures may
better be employed in combating the disease. .If all the leaves
are gathered together and burned either late in the autumn or
early in the spring, before the new leaves have expanded, the
chances of infection would be greatly lessened.
This investigation was undertaken at the suggestion of and
under the careful direction of Professor GEORGE F. ATKINSON,
Cornell University, to whom I am very grateful for help and
criticism.
AGRICULTURAL EXPERIMENT STATION
AUBURN, ALABAMA
Norte.—Since this manuscript has been sent to the publishers, I have
received type specimens of Asterella rubi, which had been sent to Professor
GEoRGE F. ATKINSON, through the courtesy of Professor F. von HOHNEL.
Because of the fact that Asterella rubi is the first Asterella to be connected with
an Actinonema, and is one of the most recently described species of this genus,
: is especially important that it be compared morphologically, with the rose
ungus. .
For the study of the structure of the fruit bodies of Asterella rubi the
cortex of some of the affected raspberry canes was imbedded in paraffin and
sectioned. The perithecia were found to possess a central pore or ostiolum.
They are entirely superficial and with a well developed structure only on the
upper side. There is no well defined stroma from which the asci arise.
By treating small pieces of the cortex with lactic acid the entire shield may
*9 See footnote 22.
* Hatstep, B, D., New Jersey Agr. Exp. Sta. Rept. 13:281. (1892) 1893.
234 BOTANICAL GAZETTE [SEPTEMBER
be loosened, and can be floated away, thus proving beyond a doubt that this
structure is wholly superficial and not subcuticular, Asterella rubi, therefore,
conforms to the present concept of the genus Asterella, but is of an entirely
different generic type from that represented by Diplocarpon rosae.
EXPLANATION OF PLATE XIII
Fic. 1.—Acervulus of conidial stage (Actinonema rosae), with a section
of one of the radiating strands at the right of the acervulus; 400
Fic. 2.—Conidia formed free in Sra the two halves are easily sepa-
rable; germination of the separated cells;
Fic. 3—Normal conidia from oe sad their method of germina-
tion; X 400.
Fic. 4.—Surface view of Diplocarpon fetes showing the shield and sub-
cuticular strands from which it developed; X 110.
Fic. 5.—Surface view of mature aia in which the shield has been
ruptured irregularly and folded back; X55.
1G. 6.—A very young stage in the development of a fruit body in which ~
the shield and the stroma from which the asci are formed are distinct; C,
cuticle; B, epidermal cells; D, ascogenous stroma; X 200
Fic. 7.—A stage in which the fruiting part of the periihecien has begun
to be Eilkereiitidted: the shield and ascogenous stroma are separate; A, young
apothecium; X 200
Fic. 8. <Dillerentintion of the asci within the apothecium; X 200.
Fic. 9.—Perithecium in which the epidermal cells still persist between the
apothecium and shield; the thin-walled cells of the upper part of the apothe-
cium form a covering over the hymenium; X 200
Fic. 10.—Perithecium in about the same stene of development as fig. 9,
but the shield and fertile stroma are completely united; X 200
Fic. 11.—Perithecium which is nearly mature; the hyoeniad covering
has broken; A, upper part of apothecium; B, shield; C, cuticle; £, epidermal
cells; XX 200.
Fic. 12.—Mature fruit body of Diplocarpon rosae; some of the cells of
the upper part of the apothecium persist at the margin; X 200
Fic. 13.—An old acervulus persisting at the side of a perithecium; X 200.
Fic. 14.—A large disciform perithecium; some asci are mature and in
others the spores have not yet been formed; the ascogenous stroma and shield
have grown together and the epidermal cells have been destroyed; 200
Fic. 15.—Section through a aging perithecium, showing the manner in
which the shield is folded back;
Fic. 16.—Mature asci and somora the spores have been discharged
apically from one ascus; 4
Fic. 17.—Ascospores of Disiacatton rosaeé; X400.
Fic. 18.—Germination of ascospores; 400
BOTANICAL GAZETTE, LIV PLATE XIII
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WOLF on ACTINONEMA ROSAE ;
eee
UNDESCRIBED PLANTS FROM GUATEMALA AND
OTHER CENTRAL AMERICAN REPUBLICS. XXXV'"
JoHN DONNELL SMITH
Rigiostachys quassiaefolia Donn. Sm.—Folia maxima 3-5-
foliolata, rhachi petioloque alatis. Racemi axillares petiolo pluries
breviores. Sepala minuta deltoidea. Discus vix ullus. Ovaria
obovoidea, stylis lateralibus, ovulis geminis.
Omnino glabra. Foliola plerumque 5 sessilia integra lanceolato-elliptica
utrinque acuminata, terminali ceteris paulo majore 12-14 cm. longo 4. 5-5 cm.
lato, rhachi oblanceolata 3.5-4 cm. longa 8-10 mm. lata, petiolo 3.5-5.5
longo anguste alato. Racemi e basi floriferi circiter 10-flori rhachis 4-5 mm.
longa crassa paleaceo-bracteosa, pedicelli 1.5-2.5 mm. longi. Sepala aegre
1mm. longa. Petala oblongo-elliptica 3.5 mm. longa. Gynophorum leviter
compressum 1 mm. altum atque latum. Ovaria leviter compressa 2 mm.
longa mox libera, stylis praeter stigmata diu connexa discretis, ovulis paulo
supra basin loculi affixis. Cetera desunt.—Specimina incompleta speciem
quamvis abnormem tamen satis pit Rigiostachydis sistere videntur
’Panzal, Depart. Baja Verapaz, Guatemala, alt. 1000 m., Apr. iach, H. von
Tuerckheim n. II. 1714
E22 3060
Eugenia (Sect. AUTEUGENIA Niedenzu; § Biflorae Berg.)
fiscalensis Donn. Sm.—Glabra. Folia coriacea ex orbiculari-
Ovato ovata gradatim obtuseque acuminata basi rotundata.
Pedunculi axillares singuli vel bini, pseudo-terminales 6~8-ni,
petiolo bis terve floribus paulo longiores basi et sub flore bibracteo-
lati. Petala oblongo-elliptica.
Arbusculus 6-metralis, ramulis dichotomis, novellis compressis purpuras-
centibus punctulatis, internodiis folio brevioribus. Folia nitida concoloria
supra pellucido-subtus-fusco-punctulata 30-37 mm. longa 17-25 mm. lata,
margine cartilagineo revoluto, nervis praeter medium supra impressum subtus
Prominentem parum manifestis, petiolo canaliculato 2-3 mm. longo. Pedun-
culi 5-7 mm. longi basi et sub flore articulati punctulati, bracteolis eciliolatis,
basalibus lineari-lanceolatis 1.5 mm. longis, apicularibus subulatis vix 1 mm.
longis, floribus praeter discum pubescentem glabris. Calycis tubus hemi-
sphaericus 1.5 mm. altus, lobi semiorbiculares concavi trinervii inaequales
I-2 mm. longi in alabastro erubescentes. Petala punctulata 4.5 mm. longa
* Continued from Bor. Gaz. 52:53. Iort.
235) [Botanical Gazette, vol. 54
yyr2?
236 BOTANICAL GAZETTE [SEPTEMBER
genitalibus subaequilonga. Discus 2 mm.-diametralis. Bacca ignota.—
E. surinamensi Miq. proxima.
/In praeruptis Barranca dictis prope Fiscal, Depart. Guatemala, Guatemala,
alt. 1100 m., Jun. 1909, Charles C. Deam n. 6226.—Typus in herb. Musei
Senacene numero proprio 579586 signatus servatur.
”! Anguria pachyphylla Donn. Sm.—Folia trifoliolata, foliolis
breviter petiolulatis coriaceis acuminatis integris, terminali obovato
basi cuneato, lateralibus oblongo-ovatis. asymmetricis. Flores
masculini sessiles. Calycis dentes minuti. Antherae lineares,
appendice ovali glabra, loculis rectis.
Robustissima glaberrima resinulas exsudans. Caulis cum petiolo communi
3-3-5 cm. longo crassus angulato-sulcatus compressus. Foliola subaequalia
16-22 cm. longa 8. 5-11 cm. lata acute incurvo-acuminata margine integerrima
nervis validis subtus elevatis utrinque 7-8 penninervia aetate provectiore glan-
dulis resinosis adspersa in sicco supra glaucescentia subtus pallidiora, foliola
exteriora inaequilateralia basi intus acuta extus late rotundata, petiolulis
complanatis 8-12 mm. longis. Cirrhi crassimi longissimi teretes striatl.
Pedunculi tantum masculini suppetentes 25-40 cm. longi complanati striati,
spica 9-13 mm. longa resinosa, floribus 20-26 ex schedula Tonduziana latericiis.
Calyx ellipsoideo-oblongus 9 mm. longus 3 mm. latus striatus faucibus haud
constrictus basi obtusus, dentibus crassis triangularibus 1 mm. longis glandula
saepius apiculatis. Petala erecta carnosa subtus elevato-costata ceterum
enervia utrinque dense papillosa ungue o.5 mm. longo exempto orbicularia
3 mm.-diametralia. Antherae 8 mm. longae 1 mm. latae, appendice 1 mm.
longa. Flores feminini et fructus desiderantur.—A. pallidae Cogn. proxima.
“VIn apricis ad praedium Twis dictum, Prov. Cartago, Cait Rica, alt. 650 m.,
Nov. 1897, Adolfo Tonduz n. 11535.—In fruticetis apud Las Vueltas, Tucur-
rique, Prov. Cartago, Costa Rica, alt. 635 m., Apr. 1899, Adolfo Tonduz n.
‘x
CucURBITACEARUM duas species ineditas peregrinas fas mihi sit
hoc loco describere, nempe:
6) Anguria tabascensis Donn. Sm.—Folia dimorpha profunde
bipartita vel trifoliolata. Flores masculini spicati. Calycis tubus
triente superiore angustatus, dentes elongato-triangulares. An-
erae breves oblongae submuticae, loculis rectis.
Glabra. Caulis tenuis striatus sulcatus. Petioli 17-27 mm. longi.
Foliorum segmenta vel foliola cuspidata margine sinuosa penninervia, biparti-
torum segmentum alterum oblongum 15 cm. longum 8 cm. latum intrinsecus
excisum extrinsecus basi 3. 5 cm. lata truncatum altero lanceolato-oblongo bis
majus, trifoliatorum foliolum terminale obovatum 10 cm. longum 5 cm. latum
deorsum attenuatum, lateralia oblonga 9 cm. longa 4 cm. lata intrinsecus excisa
1912] SMITH—PLANTS FROM CENTRAL AMERICA 237
extrinsecus basi rotundata, petiolulis 6-7 mm. longis. Cirrhi compressi
striati. Pedunculi solum masculini visi striati sulcati 17-25 cm. longi, spica
4-5 cm. longa. Calycis tubus striatus subcylindri gus basi
obtusus, dentes 2 mm. longi e ~ Petala erecto-patula utrinque
leviter furfuracea ungue 1 mm. longo atque lato exempto o -
diametralia. Antherae 4 mm. longae 1.5 mm. latae tis-
ae appendice min
sima papillosa. Flores feminini et fructus ignoti—Ad a dersifolion Cogn.
floribus arcte accedens ab ea foliis longe distat.
~ Ad ripas paludosas fluminis Macayal dicti, Comarca de Tabasco finibus
Guatemalensibus adjacens, Mexico, Jul. 1889, José N. Rovirosa n. 519.
2 Gurania brachyodonta Donn. Sm.—Folia pedatim 5-foliolata,
foliolis integris vel vix lobatis, interioribus obovatis deorsum
attenuatis, extimis semiovatis. Flores masculini racemosi. Calycis
dentes subulati tubo 2-4-plo petalis paulo breviores. Antherae
lanceolato-oblongae, appendice papillosa, loculis replicatis.
Caulis tenuis cum petiolo communi complanato 5. 5-9 cm. longo striatus
sulcatus parce patenterque pilosus. Foliola tenuiter membranacea acute
subtus nervis pubescentia, terminale 10.5-16.5 cm. longum 4-6 cm. latum
integrum vel latere altero ad medium repando-vel angulato-sublobatum,
intermedia paulo minora integra, extima 7-9 cm. longa 3.5-4.5 cm. lata
intrinsecus excisa extrinsecus basi late rotundata integra vel ad instar terminalis
sublobata, petiolulis propriis atque communibus complanatis striatis glabres-
centibus. Cirrhi tenues striati glabrescentes. Pedunculi tantum masculini
visi 9. 5-14 cm. longi tenues striati glabri, racemo 7 mm. longo, pedicellis 3-22
puberulis 4~7 mm. longis, floribus ex scheda cl. repertoris luteis. Calycis
ferme glabri tubus ovoideo-oblongus 6-9 mm. longus 3-4 mm. latus apice vix
constrictus basi cuneatus, dentes 2-2.5 mm. longi erecto-patentes. Petala
erecto-patentia oblonga 3 mm. longa 1 mm. lata acuta trinervia extus leviter
Papillosa. Antherae 3-4 mm. longae 1 mm. latae, appendice o. 5 mm. longa,
connectivo angusto. Flores feminini et fructus ignoti—G. pedatae Sprague
Proxime affinis differt calycis dentibus in genere brevissimis.
“Ad praedium El Recreo dictum, Prov. Manabi, Ecuador, Eggers n. 15084.—
In silvis prope Balao, Ecuador, Maj. 1892, Eggers n. 14691.
F2t4- 32
GARYA LAURIFOLIA Benth., var. quichensis Donn. Sm.—Folia
hitida integerrima. Inflorescentia masculina densissimiflora, spicis
corymboso-paniculatis suberectis abbreviatis, nodis et spiciferis et
floriferis approximatis.
Frutex 2-3-metralis totus siccitate nigricans. Paniculae ex solis exemplis
masculinis notae 4-6 cm. longae, internodiis 1 cm. non excedentibus.
238 BOTANICAL GAZETTE [SEPTEMBER
“Versus cacumen montis haud procul a San Miguel Uspantan siti, Depart.
Quiché, Guatemala, alt. 1800 m., Apr. 1892, Heyde et Lux, n. 3175 ex Pl. Guat.
etc. quas ed. Donn. Sm
eobt--" Alloplectus ruacophilus Donn. Sm.—Folia oblongo-elliptica
vel-lanceolata utrinque acuminata mucrone denticulata. Pedun-
culi numerose aggregati inaequilongi. Calyx leviter obliquus,
segmentis parum inaequalibus inciso-dentatis. Corolla calyce bis
longior cylindracea postice saccata ore obliqua, lobis subaequalibus
brevibus obtusis. Antherae rotundato-quadratae.
Caulis obtuse tetragonus glabrescens epidermatis squamellis retroversis
pilosis 2.5-5.5 cm. longis ad scotia cme a panduls sangumes oe
munitis. Pedunculi 6—12-ni 1-3 cm
pilosis lanceolato-ovatis 1~1.5 cm. longis fulti. Calycis ‘sanguinei segmenta
basi extus pense ereeram wigs quatuor lanceolato-ovatis 1 t: Ess cm. longs
7mm. latis tiore, dentibus
sicut apex -“nigro-mucronulatis. Corolla eruhescens villosa 28-30 mm. longa
7 mm. lata recta vix ventricosa faucibus haud contracta, lobis 1. 5 mm. longis.
Stamina ad 4 mm. supra basin corollae inserta 16 mm. longa, antheris 2 mm.
longis atque latis. Disci glandula solitaria. Ovarium ovoideum villosum.
Fructus ignotus—Ad A. tetragonum ae et A. Ichthyodermatem Hanst.
arcte accedens differt praesertim coro.
vIn silvis montis vulcanici Barba dict, Prov. Heredia, Costa Rica, alt.
2500-2700 m., Febr. 1890, Adolfo Tonduz n. 1997.—Volcin Pods, Prov.
Alajuela, Come Rica, alt. 2400 m., Mart. 1896, John Donnell Smith, n. 6729
ex Pl. Guat. etc. quas ed. Donn.Sm. (Specithina sub A. Ichthyodermate Hanst.
olim distributa.)—In silvis ad Achiote in monte vulcanico Pods dicto, Prov.
Alajuela, Costa Rica, alt. 2200 m., Dec. 1896, Adolfo Tonduz n. 10799.
>” Alloplectus tucurriquensis Donn. Sm.—Folia obovato-elliptica
sensim acuminata deorsum attenuata in petiolum decurrentia
inaequilateralia crenulato-denticulata. Pedicelli in racemo bre-
vissimo dense aggregati bractea sanguinea fulti. Calyx leviter
obliquus pedicello subdimidio longior plus minus sanguineus, seg-
mentis subaequalibus oblongis integris. Antherae oblongae.
Caulis epiphytalis esi sheer 18-28 cm. longa g-14 cm. _— perga-
mentacea supra strigilloso-pubescenti nervis
lateralibus utrinque 9-10, sticks 2-4 cm. longis tenuibus alatis. Racemorum
1912] SMITH—PLANTS FROM CENTRAL AMERICA 239
in exemplo unico suppetente haud satis evolutorum pedunculus 5~7 mm. longus,
pedicelli subfasciculati 13-18 mm. longi, bracteae optime ellipticae 26-3 . mm.
longae 13-17 mm. latae integrae reticulato-venosae deciduae. Calyx 20-28
mm. longae ad tres partes partitus extus puberulus intus glaber scacaacess
sanguineo-maculatus, segmentis obtusis reticulato-venosis. Corolla tantum
immatura cognita pubescens. Antherae 5 mm. longae. Disci glandula soli-
taria. Ovarium cinereo-pubescens oblongo-ovoideum 8mm. longum. Fructus
ignotus.—A. macrantho Donn. Sm. quam maxime affinis.
“In silvis prope Las Vueltas, Tucurrique Prov. Cartago, Costa Rica, alt.
635-700 m., Mart. 1899, Adolfo Tonduz n. 13042.
* Alloplectus oinochrophyllus Donn. Sm.—Folia leviter disparia
obovato-elliptica sursum cuspidato-deorsum cuneato-acuminata
integra subtus vinicoloria. Calyx virescens basi saccatus, segmen-
tis parum inaequalibus lanceolato-ovatis integris. Corolla recta
triente lobata. Antherae oblongae.
Epiphytalis, caule subtetragono rufescente articulato-piloso, internodiis,
4-7 cm. longis. Folia ferme glabra 8-12 cm. longa 3-5 cm. lata, altero in pare
subtriente minore, plerumque inaequilateralia falcata, nervis lateralibus
utrinque 4-5 subtus fuscentibus, petiolo piloso 1-2 cm. longo. Pedune
in utraque axilla solitarius teres pilosus 7-9 mm. longus bracteis sanguineis
lanceolatis 13 mm. longis fultus, floribus minute parceque strigillosis. Calycis
Segmenta basi connata 30-32 mm. longa 13-17 mm. lata longe attenuata,
postico ceteris simili eis paulo minore. Corollae albae (cl. repertor in
schedula), venuloso-reticulatae tubus supra basin saccatam leviter ventricosus
dein sensim paulo ampliatus faucibus haud constrictus 3 cm. longus, us
obliquus, lobi suborbiculares 1 cm. longi crenulati. Stamina ad 7 mm. supra
basin corollae inserta, filamentis 15 mm. longis, antheris 5.5 mm. longis basi
iscretis. Disci glandula solitaria acute ovata 2 mm. longa. arium
ovoideum cum stylo 8-10 mm. longo pubescens, stigmate bilobo. Fructus
desideratur.—A. Strigoso Hanst.
In silvis ad Pansamalé, Depart. Alta Verapaz, Guatemala, alt. 1250 m.,
Maj. 1887, H. von Tuerckheim, n. 1080 ex Pl. Guat. etc. quas ed. Donn. Sm. (Sub
A. strigoso Hanst. olim distributus.)—In silvis montanis prope Coban, Depart.
ie tien: Guatemala, alt. 1350 m., Aug. 1907, H. von Twerckheim n. I.
sa Alloplecti quaedam species in America Centrali nuperius
repertae sub sectionibus auctorum non satis bene militent, clavis
specierum Centrali-Americanarum adhibeatur nova opportet.
I. Calyx regularis.
A. Antherae oblongae. A. multiflorus Hanst.
B. Antherae rotundato-quadratae. A. calochlamys Donn. Sm.
240 BOTANICAL GAZETTE - [SEPTEMBER
II. Calyx leviter obliquus.
A. Antherae latiores quam longiores. A, tetragonus Hanst.
B. Antherae rotundato-quadratae.
1. Caulis squamelliferus.
a. Corolla calycem paulo superans. A. Ichthyoderma Hanst.
b. Corolla calycem bis superans. A. ruacophilus Donn. Sm.
2. Caulis nudus.
a. Calycis segmenta inciso-crenata. A, Forseithii Hanst.
b. Calycis segmenta filiformi-laciniata.
7 Folia in pare aequalia. A. costaricensis Dalla Torre et Harms.
7{ Folia in pare dimorpha. <A. metamorphophyllus Donn. Sm.
C. Antherae oblongae.
1. Folia peltata. A. pellatus Oliver
2. Folia basi petiolata.
a. Flores singuli aut fasciculati. A. macrophyllus Hemsl.
b. Flores racemosi.
+ Bracteae virescentes. A. macranthus Donn. Sm.
Tt Bracteae sanguineae. A. tucurriquensis Donn. Sm. .
III. Calyx basi saccatus.
A. Calycis segmenta parum inaequalia.
1. Folia concoloria. A. strigosus Hanst.
2. Folia subtus vinicoloria. A. oinochrophyllus Donn. Sm.
B. Calycis segmentum posticum ceteris multo minus.
1. Pedunculus multiflorus. A. ventricosus Donn. Sm.
2. Pedunculi uniflori.
a. Pedunculi bini. A. stenophyllus Donn. Sm.
b. Pedunculi 4—5-ni. A. coriaceus Hanst.
ever Ls Besleria (§ GASTERANTHUS Benth.) acropoda Donn. Sm.—
Folia lanceolato-elliptica utrinque acuminata serrata. Pedunculi
pseudo-terminales bini triflori. Calyx amplus, segmentis integris.
Corolla prona infundibuliformis calyce subtriplo longior in saccum
inflatum segmento calycino pendulo paulo breviorem producta.
Frutex terrestris, ramis junioribus subtetragonis sulcatis strigilloso-pubes-
centibus. Folia membranacea supra glabra subtus nervis venulisque pubes-
tantum ad rami apicem siti ramulo nascente comitati demum axillares ita
solitarii evadentes 15-25 mm. longi glabri, pedicellis 7-10 mm. longis glabris,
. floribus pube moniliformi adspersis. Calycis herbacei valde obliqui segmenta
. fere sejuncta, antica lanceolata 12 mm. longa, lateralia lanceolato-ovata 14 mm.
Fig?
1912] SMITH—PLANTS FROM CENTRAL AMERICA 241
longa valde a ORE semicordata, posticum orbiculari-ovatum ro mm.
longum graciliter cuspidatum. Corollae luteae tubus 3 cm. longus leviter
ventricosus parum readin limbi amplitudine subtriplo longior, eas
a ellipsoideus 8-9 mm. longus segmento calycino postico
ob
liquum, lobi breves arcuati. Stamina paulo supra basin tubi inserta
9mm. longa, antheris suborbicularibus. Discus postice incrassatus. Ovarium
glabrum valde obliquum ovatum 3 mm. longum, stylo 8 mm. longo. Fructus
ignotus.
“In silvis ad Tsaki, Talamanca, Comarca de Limén, Costa Rica, alt. 200 m.,
Apr. 1895, Adolfo Tonduz n. 9554.
ike Phyllanthus (§ EupHyLLantuus Griseb.) leptobotryosus Donn.
m.—Folia inter maxima coriacea nitida oblongo-elliptica utrinque
acuta, petiolo apice incrassato geniculato. Flores dioici. Thyrsi
masculini pluri-aggregati capillacei flaccidi pubescentes, calycis
segmentis disci glandulas liberas bis superantibus, filamentis totis
fere connatis.
Arborescens ut videtur, ramulis glabris, novellis angulosis. Folia 12-20
cm. longa medio 5-8 cm. lata concoloria minute reticulata areolis pellucida,
nervis lateralibus fortioribus utrinque 6-7, petiolis 18-23 mm. longis canalicu-
latis, stipulis nullis. Thyrsi tantum masculini visi 3-11 e pulvinulo oblongo-
elliptico pubescente progredientes pedunculo 2-4 cm. longo computato 4-10
cm. longi laxe ramosi parce flori minute bracteolati, pedunculo rhachi axibus
trichoideis, cymulis trifloris, flore medio subsessili, pedicellis lateralibus 1 mm.
filamenta subaequantes. Antherarum rimae horizontales.
-Santo Domingo de Golfo Dulce, Comarca de Puntarenas, Costa Rica,
Mart. 1896, Adolfo Tonduz, n. 7332 ex Pl. Guat. etc. quas ed. Donn. Sm.
(n. 9937 herb. nat. Cost.).
arey “OSreronyma guatemalensis Donn. Sm.—Folia supra sparsim
subtus densissime lepidota obsolete pilosa oblongo-obovata vel-
elliptica acuminata deorsum attenuata petiolo multoties longiora.
Pedicelli masculini bracteolam aequantes calyce dimidio breviores,
floribus pentameris.
Ramuli petioli racemi calyces ad instar paginae inferioris foliorum lepidoti
ceterum glabri. Folia 8-11 cm. longa 3. 5-4.5 cm. lata incurvo- vel cuspidato-
acuminata supra lepidibus albis punctata subtus lepidibus contiguis vel imbri-
catis rubiginosis peste petiolo canaliculato 2-2. 5 cm. longo, stipulis deciduis.
Racemi tantum masculini visi ad apicem ramuli versus conferti paniculato-
Tamosi. 5-8 cm. ‘ai bracteis deciduis, bracteolis late ovatis 1 mm. longis
“acutis. Calyx depresso-campanulatus 1. 5 mm. altus, dentibus 5 triangularibus
242 BOTANICAL. GAZETTE [SEPTEMBER
minutis. Discus cupulatus 5-partitus extus glaber intus glandulosus pubes-
cens. Stamina 5, puri glabris 1.8 mm. longis, loculis ovoideis o. 3 mm.
longis. Ovarium rudimentarium exiguum. Flores feminini et fructus
desunt.—Ex affinitate H. ian Muell. Arg.
In silvis prope Cobian, Depart. Alta Verapaz, Guatemala, alt. 1400 m.,
Apr. 1879, H. von Tuerckheim, n. 423 ex Flora Guat. a Keck edit—In summo
jugo inter Tactic et Coban, Depart. Alta Verapaz, Guatemala, alt. 1850 m.,
Apr. 1908, H. von Tuerckheim n. II. 2228.
Ab hac specie specimina a Herbert H. Smith in Colombia lecta numero
1952 signata sub nomine erroneo ut videtur, nempe H. laxiflora Muell. Arg.,
distributa nonnisi foliis basi vix attenuatis costa pilosis et floribus subsessilibus
distingui possunt.
Ww
oS Croton (Sect. Eurropra Muell. Arg.; § Cyclostigma Griseb.)
verapazensis Donn. Sm.—Folia petiolo longiora ovata sensim
acuminata basi rotundata subquinquenervia utrinque sparsim
stellato-pilosa. Petiolus apice stipitato-biglandulosus. Stipulae
subulatae. Racemi distanter fasciculiflori, bracteis linearibus.
Stamina circiter 15. Styli bis terve divisi.
Indumentum pilo centrali elongato stellatim pilosum in ramulis petiolis
foliis nascentibus racemis calycibus ovariis ochraceo-tomentulosum. Folia
membranacea utrinque viridia 8-10 cm. longa 5.5-7.5 cm. lata glandulis
minutis denticulata, petiolo 3-4. 5 cm. longo, stipulis primum setaceis denique
validioribus 4 mm. longis. Racemi 12-1 3 cm. longi, bracteis cito deciduis
5 mm. longis, inferioribus flores femininos simulque masculinos, reliquis
tantum masculinos, fulcientibus, pedicellis masculinis s quam feminina parum
longioribus 3-5 mm. longis. Calycis segmenta fere sejuncta oblongo-ovata,
feminina 2.5 mm. iui masculinis paulo majora margine plana. Petala
masculina oblongo-elliptica 2.5 mm. longa scariosa villosa, feminina rudi-
mentaria setacea aegre 1 mm. longa. Stamina 12-18, filamentis fere glabris
3 mm. longis, antheris subquadratis 0.5 mm. ongis. Discus masculinus
villosus, glandulis remotis orbicularibus, femininus glandulis contiguis crenu-
latis circumdatus. Ovarium subglobosum 2 mm. -diametrale, stylis plepumque
bis dichotome partitis. Capsula stellatim pubescens 1 cm. longa, seminibus
5 mm. longis fuscis leviter rugosis—Ad C. hem emiargyrium Muell. Arg. accedens..
Santa Rosa, Depart. Baja Verapaz, Guatemala, alt. 1600 m., Jul. aa
si von Tuerckheim n. Il. 2297.
— uy Croton (§ DREPADENIUM Muell. Arg.) Tuerckheimii Donn.
: Sm.—Folia coriacea nitida oblongo- vel obovato-elliptica acuminata
basi obtusiuscula vel acuta penninervia denticulata. Flores mas-
culini axillares racemosi. Calyx 6-12-lobatus, receptaculo ex-
planato tubum fere implente toto glandifero. Stamina numero-
sissima.
1gt2] SMITH—PLANTS FROM CENTRAL AMERICA 243
Arbor formosa (cl. repertor in literis), omnibus in partibus glaberrima,
ramulis petiolisque glandulosis, novellis complanatis glaucis. Folia alterna
7-9.5 cm. longa 3-4 cm. lata incurvo- vel cuspidato-acuminata margine carti-
lagineo revoluta glandulis remote minuteque denticulata, petiolo canaliculato
7-12 mm. longo. Pedunculus communis in axillis superioribus situs vix ullus
vel usque ad 7 mm. longus, pedicellis s~7 corymboso-subfasciculatis 7-14 mm.
longis, bracteis bracteolisque scariosis semiamplexicaulibus obtuse ovatis
2-2. 5 mm. longis, floribus tantum masculinis cognitis. Calycis lobi plerumque
8 cuspidato-ovati vel -triangulares parum aequales 1. 5-2 mm. longi, receptaculo
4-6 mm. lato glandis compactis compresso-subcubicis o. 5 mm. longis obsito.
Petala obsoleta. Stamina inter glandas inserta 60-85, filamentis 3-3. 5 mm.
longis, antheris ovalibus 1 mm. longis prope basin affixes. Flores feminini et
fructus ignoti.
yApud pagum Tactic dictum, Depart. Alta Verapaz, Guatemala, alt.
1550 m., Mart. 1908, H. von Tuerckheim n. II. 2163.
‘Acalypha (§ AcRosTACHYAE Muell. Arg.) radinostachya Donn.
Sm.—Dioica. Folia oblongo-ovata crenato-serrata 3-nervia. Stip-
ulae lineari-lanceolatae perlonge setaceo-productae. Spica femi-
nina gracilis longissima, bracteis dissitis unifloris deltoideo-ovatis
subintegris. Styli toti numerosissime longissimeque lacinuligeri.
Suffrutex erectus vix metralis simplex, caule petiolis foliorum nervis spica
bracteis Sparsim minuteque strigillosis. Folia nascentia dense luteo-strigillosa,
adulta glabrescentia tenuiter membranacea 13-14.5 cm. longa 7-8.5 cm.
lata graciliter acuminata basi rotundata leviter retusa, suprema conferta,
denticulatae. Sepala 3 ovata acuta 1 mm. longa. arium globosum sepala
aequans cum illis parce strigillosum, stylis 2 mm. longis, quoque lacinulis -
circiter 20-25 capillaceis simplicibus usque ad 6 mm. longis albidis biseriatim
pectinato. Cetera desunt.
___ “In silvis primaevis profundis ad fundum Suerre dictum, Llanuras-de-Santa
Clara, Comarca de Limén, Costa Rica, alt. 300 m., Febr. 1896, John Donnell
Smith n. 6849 ex Pl. Guat. etc. quas ed. Donn. Sen
rt Conceveiba (§ VeconcrBeA Muell. Arg.) pleiostemona Donn.
Sm.—Folia suborbicularia vel orbiculari-obovata abrupte cuspi-
data basi rotundata vel retusa. Pedicelli masculini singuli vel
2~4-ni inaequales medio articulati calycem nutantem i
Stamina circiter 50-60.
fe%
244 BOTANICAL GAZETTE ~--- [SEPTEMBER
Ex scheda cl. repertoris arbuscula, ramulis stipulis petiolis foliorum
utrinque nervis panicula stellatim griseo-pubescentibus. Folia nascentia
densissime praesertim in nervis utrinque tomentulosa, adulta praeter nervos |
supra glabrescentia venis venulisque subtus stellatim puberula pergamentacea
venis transversis 3-4 mm. inter se distantibus, petiolo striato 5-7. 5 cm. longo,
stipulis subulatis 5—6 mm. longis persistentibus. Panicula ex solis speciminibus
masculinis nota sessilis 12-18 cm. longa, ramis erecto-patentibus, pedicellis
plerumque trinis 2-3 mm. longis, articulo inferiore tomentuloso, superiore
nitido, bractea bracteolisque ovato-lanceolatis 1-2 mm. longis. Calyx nitidus
globosus 2.5 mm.-diametralis 2-3-partitus, segmentis demum_ reflexis.
Stamina omnia antherifera conformia, filamentis glabris 7-11 mm. longis,
antheris ob loculos late tos latioribus quam longioribus. Flores feminini
eeore deficientes.—Affinitas cum C. latifolia Benth. summa est.
as Rfo Blanco in fundo Rosario dicto, Llanuras de Santa Clara,
eich de > Limén, Costa Rica, alt. 300 m., Jul. 1899, H. Pittier n. 13425.
2)” Ampelocera hondurensis Donn. Sm.—Aculeata. Folia integer-
rima obovato-elliptica obtusiuscula basi cuneata. Paniculae foliis
2-3-plo breviores. Perianthium quinquefidum, segmentis obovatis
integris. Stamina 11-14, antheris in alabastro reversis. Ovarium
ellipsoideum stylis subtriplo superatum.
Arbuscula (cl. repertor in scheda), omnibus in partibus glabra cortice
griseo lenticellata spinis axillaribus rectis 5-11 mm. longis armata. olia
lateralibus late patulis utrinque 8-10, petiolo 4-8 mm. longo. Paniculae
utriusque sexus in ramulis distinctis sitae a basi erecto-patenter ramosae 4—6
cm. longae densiflorae siccitate nigricantes, pedicellis late patentibus basi et
medio minute bracteolatis prope florem articulatis, masculinis 2 mm. longis
quam feminini dimidio brevioribus. Perianthii segmenta nigro-punctulata
et -lineolata concava valde imbricata margine scariosa 2-3 mm. longa, masculina
fi paulo latiora. Stamina circiter 12, filamentis confertis capillaceis
2mm. longis, antheris demum erectis oblongis 1.5 mm. longis. Ovarium 2 mm.
longum, stylis 5-7 mm. longis, ovulo orbiculari complanato. Drupa ignota.—
Haec species in genere tertia ad A. Ruizii Klotzsch perianthio 5-fido ad A:
cubensem Griseb. foliis integris accedens, ab utraque inter alia spinis inflores-
centia perianthii segmentis integris staminibus indefinitis antheris primum
reversis recedit.
Secus viam prope San Pedro Sula, Depart. Santa Barbara, Honduras, alt.
200 m., Maj. 1890, Carl Thieme, n. 5606 ex Pl. Guat. etc. quas ed. Donn. Sm.
BALtTmmMorE, Mp.
INFLUENCE OF PHOSPHATE ON THE TOXIC ACTION
OF CUMARIN’
J. J. SKINNER
In connection with a study of the different effects produced
as the result of the action of several organic compounds on seedling
wheat, presented in a former paper,? it was noted that the presence
of phosphate in the nutrient solutions employed was able to mini-
mize or entirely overcome the toxic effect of the cumarin on the
seedlings. The effects of the cumarin on plant development are
_ strikingly shown on the seedling wheat. ‘The leaves are shorter
and broader than is normal for wheat, and only the first leaves
are usually unfolded, the other leaves remaining wholly or par-
tially within the swollen sheath; such leaves as do break forth
are usually distorted and curled or twisted. The disappearance
of this characteristic behavior of the cumarin affected plants was,
therefore, an additional criterion of the beneficial effect of the
phosphate in the nutrient cultures, as well as the improved growth
and better root development of the plants in general. The nutrient
solutions contained nitrate as sodium nitrate, potassium as potas-
sium sulphate, and the phosphate was added in the form of mono-
calcium phosphate.
Attention was called in the earlier paper to the fact that the
observation there recorded was obtained with the calcium acid
Phosphate, and that the observed result may -be caused, therefore,
by the salt as a whole rather than by the phosphate radical con-
tained therein, or by other specific qualities of the salt or other
constituent parts, namely by its acid properties or the fact that
calcium is present in the compound.
Several experiments were planned so as to eliminate the possi-
bility of calcium producing the result noted, and to present the
* Published by permission of the Secretary of Agriculture.
¢ INER, O., and SKINNER, J. J., The toxic action of organic compounds as
modified by fertilizer salts. Bor. Gaz. 54131-48. 1912.
245] [Botanical Gazette, vol. 54
246 BOTANICAL GAZETTE [SEPTEMBER
phosphate under different conditions, acid, neutral, and alkaline.
These requirements are met by using sodium salts instead of
calcium, and employing all three sodium salts of phosphoric acid,
namely, the monosodium phosphate (NaH,PO,), which like the
calcium acid phosphate of the first experiment is decidedly acid
in reaction; the disodium phosphate (Na,HPO,), which is neutral
toward phenolphthalein; and the tribasic sodium phosphate
(Na;PO,), which is alkaline in reaction. In all other respects the
culture solutions were the same in concentration and composition
as described in the earlier paper, the full number of 66 cultures as
there described being used, both with and without the cumarin
and, as in the paper cited, comparisons are always made between
solutions of like composition as far as the mineral salts are con-
cerned. This comparison, of course, can be made between indi-
vidual cultures of like composition or between groups of cultures,
when members of like composition occur in both groups.
Effect of monosodium phosphate
The 66 culture solutions of equal concentration (80 p.p.m. of
P,O;+K,0+NH,), but varying in composition as far as the ratios
of phosphate, potash, and nitrate are concerned, were prepared
according to the scheme presented in the earlier paper cited.
The sets were always in duplicate, the one containing only the
nutrient salts and considered as the normal set, the other contain-
ing in addition to the salts 10 p.p.m. of cumarin. The plants
grew from October 17 to 29. The green weight at the termination
of the experiment for the growth in the 21 cultures composed of
mainly phosphatic fertilizer (one-half and more of the nutrients
being phosphate) was 38.6 grams. Similarly the green weight of
the cultures composed of mainly nitrogenous fertilizer was 42-°
grams, and in the cultures composed mainly of potassic fertilizers
it was 41.8 grams. The results in the normal set were: for the
mainly phosphatic fertilizers, 39.3 grams; for the mainly nitroge-
nous fertilizers, 49.9 grams; for the mainly potassic fertilizers,
46.9 grams. These results are tabulated in table I, which also
gives the results relatively expressed in terms of the normal culture
taken as 100.
1912] SKINNER—PHOSPHATE AND CUMARIN 247
It will be seen that the mainly phosphatic cultures gave a
growth in the presence of cumarin which was nearly as good as
in the cultures without cumarin. The growth relatively expressed
was 08 per cent of the normal. With the other groups it was 84
and 89 per cent. The result with the monosodium phosphate is
therefore similar to the action of the monocalcium phosphate
reported in the earlier paper, a fact which is also shown by the
appearance of the plants in the cultures composed of mainly
phosphatic fertilizers, the plants having lost entirely the character-
istic effect of the cumarin above referred to, an effect which is
TABLE I
SHOWING THE EFFECT OF THE MAINLY PHOSPHATIC, MAINLY NITROGENOUS, AND
MAINLY POTASSIC FERTILIZERS ON CUMARIN
Phosphate as monosodium phosphate
GREEN WEIGHT
FERTILIZERS COMPOSED OF 50 TO RELATIVE peitoiry 6
oo R CENT OF J4 ee
Normal bilaerhnd =
grams grams
RMN Secs, 390-3 38.6 98
Pee oe 49.9 42.0 84
PE 46.9 41.8 89
Strongly marked in the cultures low in monosodium phosphate as
well as in those low in calcium acid phosphate. This experiment,
therefore, disposes quite effectively of the supposition that the cal-
cium in the phosphate salt played any significant part in the
observed action, since the same action in all particulars is possessed
by the monosodium phosphate. There remains the question of
the influence or action of the acid character of both phosphates
in bringing about the observed result. For this purpose culture
€xperiments in which the acid phosphates were replaced by neutral
and even alkaline phosphates were made.
Effect of disodium phosphate
The plants in this experiment grew from November 1 to 12,
and the results are presented in table II, the grouping being again
made on the basis of the composition of the nutrient salts in the
248 BOTANICAL GAZETTE ea [SEPTEMBER
cultures, that is, into the groups mainly phosphatic, mainly nitroge-
nous, and mainly potassic.
TABLE II
SHOWING THE EFFECT OF THE MAINLY PHOSPHATIC, MAINLY NITROGENOUS, AND MAINLY
POTASSIC FERTILIZERS ON CUMARIN
Phosphate as disodium phosphate
GREEN WEIGHT
FERTILIZERS COMPOSED OF 50 TO RELATIVE pect y (NORMAL
=I00
ee With 10 p.p.m.
cumarin
Normal
gta ms
PRORDNAIGS oe eo 36.3 34.1 04
PRICIER GT ee es 45.8 40.3 88
SOiterhs ana civ ewes 44.5 38.2 86
Here again the effect of the mainly phosphatic fertilizers is
the same as with the monobasic salts already discussed, although
this effect is not as marked in this experiment. There remains
the trisodium phosphate of alkaline reaction to be studied in this
regard.
Effect of trisodium phosphate
The plants in this experiment grew from November 29 to
December to and the results are given in table III.
TABLE III
SHOWING THE EFFECT OF THE MAINLY PHOSPHATIC, MAINLY NITROGENOUS, AND MAINLY
POTASSIC FERTILIZERS ON CUMARIN
Phosphate as trisodium phosphate
GREEN WEIGHT
FERTILIZERS COMPOSED OF 50 TO RELATIVE — (NORMAL
100 PER CENT OF =
Nomal | With op-pm.
grams grams
PROMBAE 3a 37.0 33-9 gt :
IWR eee i ck 42.4 34.6 81
Poth. ois iis ee 42.9 3t.7 74
These figures show that the effect of this alkaline reacting
tribasic phosphate has the same effect in overcoming the toxic
action of the cumarin as had the calcium acid phospiet the
1912] SKINNER—PHOSPHATE AND CUMARIN 249
monosodium phosphate, and the disodium phosphate. The
reaction of these various phosphates, and probably also the presence
of the calcium, appears to modify this action, as indicated by the
different figures, but it in nowise determines the effect itself.
The conclusion seems warranted that the peculiar action of these
phosphate salts in overcoming the toxic action of cumarin is due
to the phosphate radical and not to the presence of any particular
base, or the acid or alkaline reaction of the nutrient solution.
LABORATORY OF FERTILITY INVESTIGATIONS
B
UREAU OF SOILS
WasuHincton, D.C.
BRIEEER ARTICLES —
ABSORPTION OF anny CHLORIDE BY ARAGALLUS
LAMBERTI
During-the progress of some experimental work on loco plants at
Hugo, Colorado, we were led to suppose that these legumes contained
much more barium salts than other plants growing in the same locali-
ties, and presumably possessed some qualities which enabled them to
withdraw more of these salts from the soil. The question arose whether
an increase of the quantity of barium in the soil would be followed by a
corresponding increase in the plants, and to this end a series of experi-
ments was undertaken. These experiments were not carried out as a
complete study of the question, and were discontinued after the facts
were obtained which had an immediate bearing on the problems which
were under consideration. While the work was only preliminary in
character, the results obtained may be of interest to others, and inasmuch
as this work will not be continued, it may be best to publish the facts for
the use of those who may be studying similar problems. While the
general plan of the experiment was outlined by the writer, the detail
was carried out by Assistant HapLteicH Marsu. A plot of ground was
selected on the ranch of Mr. OLson, near Hugo, where Aragallus Lamberti
grew with especial luxuriance. This plot was fenced in order that
grazing animals might not interfere with the progress of the experiment.
EXPERIMENT NO. I
Six thrifty plants of Aragallus Lamberti were selected for barium
chloride treatment, and 7 plants, somewhat smaller, were selected for a
control by treatment with an equal amount of water. A shallow trench
was dug around each plant. These trenches were filled daily with barium
chloride solution in the case of the plants experimented upon, and with
an equal quantity of water in the case of the control plants. The barium
chloride was applied in a 10 per cent solution. The solution was made
with water containing some sulphates, so that there was a slight precipi-
tation of sulphate of barium when the solution was made, but it is not
* Published by permission of the Secretary of Agriculture.
Botanical Gazette, vol. 54] [25°
1912] BRIEFER ARTICLES 251
to be presumed that this made any material difference with the amount
of barium chloride in solution. Two liters of barium chloride solution
were applied to each of the experimental plants daily. The 1o per cent
solution was used from July 8 to July 11, 1908, inclusive. On July 13,
5-5 per cent solution of barium chloride was used. No more of the
solution was applied, and on July 18 it was found that the plants treated
with barium chloride solution had turned yellow and dried up, while
those treated with water were still green and fresh. The grass which
surrounded the trenches did not seem to be affected by the barium
chloride solution. Both sets of plants were dug and dried for chemical
analysis.
Unfortunately the plants treated with water were by mistake thrown
away, so that no analysis could be made. However, an analysis was
made of Aragallus Lamberti collected on the tract adjacent to the
fenced patch at about the time when this experiment was going on, and
this will serve as a basis of comparison, though not having the value
of an analysis of the control plants. The analyses were made by the
Bureau of Chemistry. The plants treated with barium chloride showed
ash 41.08 per cent and barium 1.32 percent. The Aragallus Lamberti
collected in the area adjacent to the experimental plot showed ash
22.08 per cent and barium o. 106 per cent.
EXPERIMENT NO. 2
Inasmuch as it was shown that a 10 per cent solution of barium chlo-
ride was poisonous to Aragallus Lamberti, it was decided to use a very
much more dilute solution and to duplicate the preceding experiment,
using a 0.1 per cent solution.
In this experiment 9 plants were chosen for the barium chloride
treatment, and 9 similar plants for the control experiment with water.
Sixteen liters of barium chloride solution were used daily on the experi-
mental plants, and 16 liters of water on the control plants, with the
€xception of one day when 14 liters were used. This experiment was
Carried on from August 4 to August 18, inclusive. During this time both
8roups of plants continued healthy and showed no effect of the treat-
ment. On August 20 both sets of plants were dug up and dried for
analysis, these analyses, as in the other cases, being made by the Bureau
of Chemistry. The plants treated with barium chloride showed ash
52-26 per cent and barium o.20 per cent. The plants treated with
Water showed ash 22.98 per cent and barium 0.0613 per cent.
252 BOTANICAL GAZETTE [SEPTEMBER
EXPERIMENT NO. 3
In the third experiment, the barium chloride was used in a 1 per cent
solution. As in the preceding experiments, one group of plants was
watered with the barium chloride solution and the other with an
equal amount of water. Sixteen liters of the barium chloride solution
and of water, respectively, were used daily in this experiment. This
was commenced on September 15, and was continued to September 21,
inclusive. At this time both groups of plants were in good condition,
showing no ill effects from the treatment. On September 22 the plants
were dug up and dried for analysis. The analyses, made by the Bureau
of Chemistry, showed the following results: the plants treated with
barium chloride, ash 37.095 per cent, barium 0.636 per cent. The
plants treated with water showed no barium
RESULTS
These preliminary experiments appear to show the following results:
That plants of Aragallus Lamberti endure barium chloride solution as
strong as I per cent with no bad effects, while a 10 per cent solution
is distinctly poisonous. Grouping the analyses, we find that the
largest amount of barium was found in those that were treated with
the 10 per cent solution, a less amount in those treated with the 1 per
cent solution, and a still less in those receiving the o.1 per cent solution.
In other words, it appears that in these experiments the quantity of
barium salts absorbed varied directly with the amount in the soil.—C.
Dwicut Marsu, Bureau of Plant Industry,U.S. Department of Agriculture.
CURRENT LITERATURE
BOOK REVIEWS
_ Lotsy’s textbook
The first part of the third volume of Lorsy’s Vorirége iiber botanische-
Stammesgeschichte' begins with the Coniferae and ends with Casuarinaceae.
There are 1055 pages and 661 figures, scarcely any of which are original h
principal literature, especially the morphological, is gathered together and
illustrations are lavishly reproduced, often whole plates, rather than merely
the figures bearing upon the subject. In the case of such an extensive work
it would be impossible to give any lengthy summary or to discuss even the
principal conclusions, but a few points might be noted.
In concluding the 286 pages devoted to Coniferae, he finds that the
phylogeny is still uncertain, but that they must have come from the great
Filicales complex, and that they contain forms in which the ovulate structures
should be called a flower and others in which they constitute an inflorescence;
consequently, those who are convinced that the angiosperms have come from
the Coniferae are at liberty to regard the angiosperm flower as either a strobilus
or an inflorescence. Lorsy continues in his previous belief that the Gnetales
have not given rise to the angiosperms, but rather represent the end of an
evolutionary line.
The monocotyledons, with the exception of the Spadiciflorae, which Lotsy
places near the Piperales, form a consistent group, and have been derived from
the dicotyledons. The Alismaceae are regarded as the most primitive family
and the Orchidaceae as the most advanced. The various families are con-
sidered seriatim, and their external habit and internal morphology are well
illustrated, but there is little effort to show general tendencies.
Attention may also be called to a few*details. In considering Gnetales,
CouLTEr’s interpretation of the tissue at the base of the free nuclear embryo
Sac is questioned, but no new evidence is introduced. In the opinion of the
reviewer, CouLTER’s interpretation is correct and Lorsy’s own preparations
would show the boundary of i or sac between the free nuclear portion
and the so-called antipodal regi
Iss PACE’s interpretation a the embryo sac of Cypripedium is also ques-
tioned, Lorsy regarding the two cells resulting from the first division of the
neta
, J. P., Vortriige iiber botanische Stammesgeschichte, gehalten an der
Sac zu Leiden; ein Lehrbuch der Pflanzensystematik. Dritter near
Cormophyta eee Erster Teil. 8vo. pp. 1055. figs. 661. Jena: Gusta
Fischer. r91r,. M 7.1
253
254 BOTANICAL GAZETTE [SEPTEMBER
megaspore mother cell as two megaspores. This is a surprising conception of
the megaspore, for it would mean that a megaspore (and presumably a micro-
spore) could be formed with only one of the reduction divisions, that is, the
megaspore would be completely formed at the close of the heterotypic mitosis.
Cytologists will hardly accept such an interpretation.
The angiosperm embryo sac is interpreted as consisting of micropylar
and an antipodal archegonium. This is another view which can hardly be
accepted by one who has followed the gradual reduction of the female gameto-
phyte from the bryophytes to the spermatophytes.
The book brings together an immense amount of material and will be
useful just as an encyclopedia is useful. In such voluminous publications
pe eae &, is not to be expected. There is a general index and an index of
plant Many references to literature are given in the text, but the
canmieta | igh will be deferred until the work is complete -——CHARLES
J. CHAMBER
MINOR NOTICES
Forestry in Indiana.—The annual report of the Indiana State Board
of Forestry? for the past year contains two papers of more than usual interest.
The shorter, by STANLEY COULTER, contains a valuable mass of data on the rate
of growth of various native tree species found upon the state reservation. Its
study should make the selection of the best species for forest planting an easier
matter, while at the same time it serves to emphasize the importance of con-
serving what has been the product of centuries of plant activity.
he longer article, by C. C. Dram, the secretary of the board, is an illus-
trated descriptive list of the tree species native to the state and occupies 27°
ages of the report. Excellent botanical descriptions of some 125 species are
ap by full-page drawings of leaves and fruit, together with notes
economic uses and horticultural value of the trees, making it a
Bu handbook of the forests of the state-——Gro. D. FULLER.
NOTES FOR STUDENTS
- Recent work among gymnosperms.—STILEs; has investigated some
material of Podocarpus, Dacrydium, and Microcachrys, and has made it the
- basis of a synthetic presentation of the classification, morphology, history,
and phylogenetic connections of the group. The bringing together of this
wealth of details in an organized form will serve the very useful purpose not
only of suggesting genetic connections but also of indicating the important
gaps in our knowledge. The general features of the group are summarized
p tly under t} g vegetativ rga ns , spore-producing
clear ly
2 Eleventh annual report of Indiana State wien : Forestry for the year 191T-
pp. 372. pls. 133. Indianapolis: Wm. B. Burford.
3 Stites, WALTER, The Podocarpeae. Ann. peas 26:443-514. figs. 8. pls.
46-48. 1912.
1912] CURRENT LITERATURE 255
members, and gametophytes. The most interesting feature of every such
review of all the available knowledge in reference to a group is the conclusion
as to its phylogenetic connections. In this case it is said that “‘the Podocarpeae
are probably related to the Araucarieae, and, though to a much less extent,
to the Abietineae.” These connections have certainly long been obvious, as
well as the absence of any evidence of a close connection with the Taxeae.
The following statement, however, is not so obvious: “A consideration of the
available evidence shows that there is much to be said for the view that regards
the Coniferales as descendants of paleozoic lycopodialean ancestors.” Much
may be said for this view, but none of it seems convincing.
Gisss‘ has studied the development of the “female strobilus’’ of Podo-
carpus, a structure that certainly needs elucidation. It seems that the diffi-
culties of interpretation disappear when the early stages of the strobilus are
studied, thus eliminating the confusion of secondary modifications. Such a
study “strikingly reveals the relationship of the axis to the strobilus or cone of
Abietineae and its component parts.” This includes the conclusion that
the “‘ovuliferous envelope” of the podocarps is the equivalent of the ovulifer-
ous scale of the Abietineae, which fuses “more and more till finally it merges in
the ovular integument in Torreya and Cephalotaxus.” The reduction in the
structure are given which add materially to our knowledge of this interesting
genus.
STILEsS published a brief note on the gametophytes of Dacrydium before
the appearance of his comprehensive paper on the podocarps noted above.
The details given emphasize the resemblance of the male gametophyte to those
of Podocarpus and Phyllocladus, and the closer resemblance of the female
gametophyte to that of Phyllocladus than to that of Podocarpus. It is becoming
increasingly evident that Phyllocladus is a podocarp rather than a taxad.
Miss Durute® has investigated the anatomy of Gnetum africanum,
a climbing species. Details are given of the structure of xylem, ete pith,
medullary sy cortex, latex tubes, epidermis of stem, cork, and leav
PEARSON’ has investigated three species of Gnetum (G. pee G.
africanum, and G. Buchholzianum), the study of the microsporangium and
‘ Grass, L. S., On the development of the female strobilus in Podocarpus. Ann.
Botany 26: 515-571. pls. 49-53. 1012.
5 STILEs, Seip A note on the gametophytes of Dacrydium. New Phytol. ro:
342-347. figs. 4.
° Dum, soc V., Anatomy of Gnetum africanum. Ann. Botany 26:593-
602. pls. 57-50
7 PEARSON, = = + , On the microsporangium and -microspore of Gnetum,
with some notes on the siemens of the inflorescence. Ann. Botany 26:603-620.
Jigs. 6. pls. 60, 61. 1912.
256 BOTANICAL GAZETTE [SEPTEMBER
microspore being chiefly those of G. africanum. The inflorescence is described
and also the details of spermatogenesis from the mother cell to the microspore,
the reduced number of chromosomes being 12. Great interest attaches to the
male gametophyte of Gnetum, but the present account does not clear it up. At
pollination, three free nuclei were observed in the pollen grain, which “are
probably to be identified as one prothallial, one vegetative (tube), and one
generative.” Since Lotsy has figured three free nuclei in the pollen tube of
um Gnemon, which were obviously a tube nucleus and two male cells, the
free “prothallial nucleus” in the pollen grain is open to doubt. One would
like to be sure whether Gnetum has eliminated prothallial tissue or not. The
author says that “the germination of the microspore and the structure of the
pollen grain point to a much closer degree of affinity with Welwitschia than
with Ephedra, ” a conclusion which all other structures confirm.
Gorpon® discovered ray tracheids, both marginal and _inter-
spersed, in old stem wood of Sequoia sempervirens. Since the wood of this
form is primitive enough in features to suggest its comparison with root wood,
the presence of ray tracheids is especially interesting.
W. as published an interesting account of Williamsonia, a genus
which he has done so much to elucidate. A few years ago a problematical
genus, it has now emerged clearly as a prominent Mesozoic group. Anaccount _
is given of its discovery, its structure, and its phylogenetic connections. Its
great range in habit, its variations in the structure of the strobilus, its variable
foliage, all suggest wide relationships, and among these suggested relationships
WIeELAND sees emphasized his contention that the angiosperms have been
derived from the Bennettitales.
The same author,” in continuing his studies on the trunks of Cycadeoidea,
has discovered that some of the supposed young strobili are mature ones of
knowledge as to the range of variation in the structure of the strobilus. These
reduced or simplified forms of course are more suggestive of the structure of
the angiosperm flower.—J. M. C
Inheritance of doubleness in stocks.—Doubleness in stocks (Matthiola)
presents one of the most complicated cases of inheritance yet thoroughly
studied, but Miss SauNpERs" has developed a scheme which allows a consistent
8 Gorpon, MArjorte, Ray tracheids in Sequoia sempervirens. New Phytol.
11Ici-7. figs. 7. 1912.
® WiELAND, G. R., On the Williamsonian tribe. Amer. Jour. Sci. 3224337460
figs. 18. 1911.
% WIELAND, G. R., A study of some American fossil cycads. Part VI. On the
smaller flower-buds of Cycadeoidea. Amer. Jour. Sci. 33:73-91- figs. I1- 1912-
™ SAUNDERS, Miss E. R., Further experiments on the inheritance of “ doubleness”’
_ and other characters in stocks. Jour. Genetics 1: 303-376. pls. 2. figs. 2. I911-
1912] CURRENT LITERATURE 257
and orderly presentation of most of the facts brought to light by extensive
cultures, and by means of which the results to be secured from any particular
mating is capable of prediction with a fair degree of accuracy. Double stocks
are totally sterile and must always be derived from singles, either self-fertilized
or crossed with other singles. Single stocks are of two kinds with respect to
their relation to doubl namely, “‘#o-d-singles”’ which breed true to single-
ness when selfed or crossed with others of their own kind, and “d-singles
doubles being generally in excess of the singles. Reciprocal crosses between
d-singles and no-d-singles give unlike results, owing apparently to a dif-
ference in the genotypic constitution of eggs and sperms in the d-singles,
the eggs being of two sorts while the sperms are all equal. Doubleness is
recessive and disappears in the F,, but when the d-single is the seed-parent
the F; singles are of two sorts, some breeding true to singleness, others pro-
ducing both singles and doubles. When the d-single is the pollen-parent,
the F, singles are all of one kind and all give both singles and doubles in F>.
The ratios of singles to doubles in the pure-bred d-single race have always
been suggestively near 7:9, thus indicating that the difference between singles
and doubles involves two genes instead of one.
Miss SAUNDERS assumes that singleness is due to the presence of two
factors X and Y, the absence of one or both of these resulting in doubleness.
If these two factors were independent, the expected ratio would be 9g singles to
7 doubles, but if they are coupled according to the scheme discovered in sweet
observed. The experimental results accord well with this assumption, and
make it probable that the coupling is of the form 15:1:1:15, though possibly
7:1:1:7. The peculiar feature in stocks, however, as compared with the
coupling in sweet peas, is the fact that neither X nor Y are carried by the
pollen, and the coupling can show itself only in the constitution of the eggs.
The crosses with no-d-singles resulted in an unexpectedly small number of
doubles in F., owing, as proved by further breeding, to the fact that in the
no-d-single race singleness is not produced by the joint action of X and Y,
but of a similarly coupled pair X’ and Y’. To further complicate the situa-
tion, there occurs a “sulfur-white” d-single race in which the plastid-color
is also “eversporting” in a manner quite similar to doubleness, the pure-br
Progenies always consisting of whites and creams as well as doubles and singles,
the singles being all white, the doubles mostly cream but also sometimes
white. The white plastids are assumed to be due to a factor W which is
borne by only a part of the eggs and by none of the sperms. Moreover W
1S coupled with one of the factors for singleness, either X or ¥. Although in
the pure d-single strains X , Y, and W are carried only by the eggs, crosses
between d-singles and no-d-singles of different plastid-color produced heterozy-
Sous F, plants in which both pollen and eggs carried the coupled series of
genes.
258 BOTANICAL GAZETTE [SEPTEMBER
In an appendix the author shows that the increase in proportion of doubles
derivable from old seed is due to the greater longevity of the seeds which lack
X and Y, and not to any change in the genotypic nature of any single seed.
She also tried to separate singles and doubles on the basis of seed-characters,
but was able to do this only in the sulfur-white race, and then not by the
character for doubleness, but by the white or cream plastid-color, which as
stated above proved to be coupled with one of the factors for singleness. Ten-
week stocks are much branched and the Brompton stocks unbranched. The
unbranched condition is recessive, but the ratio is somewhat modified because
typica “ unbranched plants will develop some branches when the terminal
bud is injured. Notes are also appended regarding the inheritance of several
EE Iie rose, lilac, terra-cotta, carmine, and crimson.—GEo. H. SHULL.
Biology and taxonomy of Gymnosporangium.—A monograph treat-
ing of Gymnosporangium both in its biological and its taxonomic aspects is
the outcome of several years of experimental and observational work on that
genus by Kern.” The work is divided into two o = first dealing with
the biology and the second with the taxonomy of the
In Part I the biology of the genus is discussed ue he following general
reference to the distribution of their hosts. The main facts are arranged in
convenient tables. The forms associated with the two sections of Juniperus
resent the most interesting features in regard to their distribution. The
species which occur on the section Sabina belong either exclusively to the
western or exclusively to the eastern hemisphere, while of those occurring
on species of the section Oxycedrus some are common to both hemispheres
and others are limited to one hemisphere. These facts lead the author to
the conclusion that the forms found on the older section (Oxycedrus), some of
whose species are distributed over all the continents of the northern hemisphere,
were distributed with their hosts “during a geological period when the lan
conditions permitted migrations between the northern continents.” The
author supposes that the section Sabina has developed from the section Oxy-
cedrus since the continents have become isolated, therefore “we would not
expect to find the same species, either of hosts or fungi, indigenous in North
America and in the Old World; and this, indeed, is the case.”” This view of
course implies the independent origin of species of the section Sabina in the
two hemispheres.
Regarding the limited geographical distribution of species of Gymno-
sporangium in cases where both the hosts have a wider distribution, no satis-
» KERN, Frank Duny, A biologic and taxonomic study of the genus Gymnospo-
rangium. Bull. N.Y. Bot. Gard. 7:392-494. 1911
1912] CURRENT LITERATURE 259
factory conclusions can be deduced from the data at hand. The apparently
limited distribution of the fungus may merely indicate a scarcity of collections.
A table indicating distribution of the species shows in general that the teleuto-
spore generation is more restricted as to its hosts than the aecidial generation.
Only 4 genera (5 if the two sections of Juniperus are considered as genera)
serve for hosts of teleutospores, while 15 genera serve as aecidial hosts, Cratae-
gus and Amelanchier being in the lead among these. While the aecidial genera-
tion has always been regarded as confined to the Pomeae, the work of recent
years has shown that one form has aecidia on Gillenia (Porteranthus) of the
Spiraeeae, and another on Fendlera and Philadelphus of the Saxifragaceae,
while G. bermudianum is autoecious.
Part II comprises the systematic treatment of the genus, 40 species being
recognized and described, the descriptions being i in most cases accompanied
by figures of spores or peridial cells showing characteristic features. Of the
40 species known in the world, 29 are known in their complete life cycle, 7
are known only in their aecidial phase, and 4 only in their telial phase. Gym-
nosporangium fraternum, G. juvenescens, and G. effusum are described as new,
and the aecidial hosts of three species are reported for the first time. The
taxonomic treatment is preceded by two sets of keys based respectively on the
characteristics of the fungus and on those of the hosts. Most of the species
are admirably illustrated by halftone plates.—H. HassELBRING.
Inheritance of root-form and color in beets and turnips.—The large
number of varieties of beets and turnips characterized by distinctive forms
to genetic investigation. Kayanus®% has undertaken the difficult task of
analysis. As a first approximation to a complete solution of hereditary
form-relations in beets, he finds the probable existence of six independent
genes affecting the form, namely, two genes (LZ; and L.) which produce an
elongation of the roots, two (A; and A.) which cause the roots to be taper-
inted below, an inhibitor (B) which opposes the action of the elongation-
Senes, and another (O) which opposes the action of the taper-point genes.
When B and O are not present, the long and tapered forms are epistatic over
the short and blunt forms, but when these inhibitors are present, the apparent
dominance is reversed. The evidence for the existence of these genes consists
at present wholly in the occurrence of the ratios 3:1, 15:1, and 1:3 in the F,.
In most of the reported crosses the results run fairly close to these ratios, but
—————hiny
3 Kayanus, B., Genetische Studien an Beta. Zeitschr. Ind. Abst. Vererb.
6:137-179. pis. 9. figs. 2. rorr
, Mendeélistische Stadion an Riiben. Fiihlings Landwirthsch. Zeitg.
61: 142-149. ror2.
———., Genetische Studien an Brassica. ee Ind. Abst. Vererb. 6: 217~-
237. pls. 4. 1912
260 BOTANICAL GAZETTE [SEPTEMBER
when so many determiners affect the same character, the F, ratios are only
suggestive and not decisive. Until a third and perhaps still later generations
have been grown, the assumptions made by the author remain hypothetical,
but with the weight of the observed F, ratios in their favor. In the Brassicas
studied, the situation appears to be much simpler. In the turnip-rooted
cabbages or Swedes (B. Napus) the roots are always approximately globular,
but in the turnips (B. Rapa) both globular and elongated forms occur and there
appear to be, just as in beets, two elongation genes (Z, and L.). Here again
the evidence for these two genes is the appearance of the long and round
forms in the F, in the ratio 15:1, and a later generation must decide the cor-
rectness of the interpretation.
In regard to the color of the roots the situation is also quite complex,
perhaps even more so than in respect to form. Red is in some cases dominant
to its absence, in other cases recessive (owing probably to the presence of an
inhibitor), and it may appear in crosses between two whites, white and yellow,
indicating the existence of more than one gene capable of producing independ-
ently the same color-character. In turnips the upper portion of the roots
is red, green, or yellow, each of these colors being epistatic to those following.
The lower portion of the roots is white or yellow, having the same color as
the flesh, the white being epistatic to yellow. In the turnip-rooted cabbages
the heads are either violet-red or green. There are two independent genes
which produce violet-red pigmentation, the one giving a light red, the other
a dark red. As the latter is completely epistatic over the lighter color, a
cross in which both of these genes and their absence are involved, produces an
F, progeny consisting of dark red, light red, and white, in the ratio 12:3:1.
Both in form and color the heterozygotes are often intermediate, so that a
more or less completely continuous series of forms is produced, thus making
the analysis difficult. This fact makes very important the promised con-
tinuation of the work.—Gro. H. SHULL
Inheritance in ees ILSSON-EHLE* gives a further report on his long-
continued experiments in the crossing of wheat varieties, dealing this time espe-
cially with the baa of the spikes and resistance to yellow rust (Puccinia
glumarum). Both of these characters are lacking in the definiteness which has
made the study of many alternative characters easy and the results clear-cut
and decisive, but the author’s earlier demonstration of several independent
genes producing the same apparent character in seed-color of wheat and in the
awns of oats has given a key to these more difficult cases. The density of the
spikes is apparently modified by three distinct genes, two of which (Z; and L,)
4 Nitsson-ELe, H., Kreuzungsuntersuchungen an Hafer und Weizen. Il.
Lunds Universitets Arsskrift. 7:no. 6. pp. 84. 1911.
1912] CURRENT LITERATURE 261
peomete elongation « the heads, = the third (C) acts as an inhibitor which
fthe heads. When all of these factors are
absent, a moderately dense head results, as exemplified by the ‘‘squarehead”’
is sufficiently decisive to leave little doubt of the essential correctness of the
interpretations. .The discovery that several genes may affect quantitatively
the same external characteristic has given an explanation of some hybri
progenies which have seemed to breed true to characters intermediate between
the parents, and it also explains the intensification of parental characters in
F, individuals which have often been observed. As an example of the latter
phenomenon, a cross between two wheats of intermediate density, having
the formulae CL,L, and ci,/,, produces some F; plants with very dense heads
(Ci,1,), and some with very lax ones (cL,L,). In respect to rust-resistance, the
difficulties of analysis are still greater and the author makes no attempt to
need particular genes, but the results of a large aeunbet of tests in second
and third generations show very clearly t facts, namely, that there
is a segregation of different grades of resistance i in the F2, and that the matter is
not generally as simple as BIFFEN found it to be in his crosses dealing with this
problem. In none of Nitsson-EHLE’s crosses was there an indication of a
simple monohybrid ratio (3:1) for sen apeny as. was found by BIFFEN.
‘ANUS® reports an instance in which the spelta-character (zigzag rachis
and adherent glumes) is recessive to the sateite chibi (straight rachis and
free glumes), a situation exactly the reverse of that found by von
This indicates that there are two genotypes of one or the other of these tiie
Phenotypes, thus paralleling the now frequently demonstrated existence of
dominant and recessive whites. Kayanus found presence of awns recessive
to their absence, and hairiness of the glumes dominant to its absence,
as in all other reported crosses in which these characters have been irivolved.
—Gero. H. Sxutt,
are described as new. The first part ot the paper consists of biclogical observa-
tions, among which will be found many valuable suggestions to anyone under-
g similar work. The zoospores are shown to have two equal flagella
*s Kayanus, B., Zur Genetik des Weizens. Botaniska Notiser 1911: 293-206.
® Barrett, J. T., Development and sexuality of some species of Olpidiopsis
(Cornu) Fischer. Aun. Botany 26: 209-238. pls. 23-26. 1912
262 BOTANICAL GAZETTE =. [SEPTEMBER
springing from the same point, although one is directed backward and sidewise
in such a manner as to give the appearance of the short lateral cilium that has
hitherto figured in the descriptions of this and some other genera of biflagellate
Archimycetes. They are distinctly diplanetic and show a pulsating vacuole
during the interval between the two periods of activity. Soon after infection
the young parasites are lost to view in the host protoplasm, but retain their
individuality and develop into zoosporangia without fusing to form plasmodia.
The parasite becomes coenocytic by nuclear division on the beginning
of growth. The nuclei, which show the complete concentration of the chro-
matin into the karyosome characteristic of most chytridiaceous nuclei, appear
to divide exclusively by mitosis of a type not very dissimilar from that
of Synchytrium, but no astral bodies were seen. The chromosomes are approxi-
mately sixin number. Segmentation is believed to be simultaneous, and begins
at least before the sporangium enters the period of rest which it often under-
goes before sporulation. The formation of resting spores was found to be
dependent on conditions in the culture which are described. The small
adjacent cells are definitely shown to be antheridia and the transfer of their
coenocytic protoplasm to that of the egg is figured. The number of nuclei of
the-gametes unfortunately is not stated, but one would judge from the figures
that it approximates 100. The fate of the male pronuclei after entering the
egg could not be definitely followed, but it is believed that they fuse in pairs
with the female pronuclei. The author concludes that “these forms seem to be
rimitive sexual organisms of the oomycete type. The influence of external
conditions on the development of the sexual stage, the mode of fertilization, the
unequal size of the two gametes, and the apparent morphological equivalence
of these gametes with the sporangia, seem to the writer to point to that assump-
tion.” —Rosert F. Grices.
An epiphytic Tillandsia.—The “ball moss,” Tillandsia recurvata, is
found growing epiphytically upon many tree species in the vicinity of Austin,
Texas, in such abundance as to be detrimental to its host. BrrcE*7 has foun
that any damage resulting to the supporting tree must be due to interferenc ‘
with the light supply, as the short holdfast roots merely furnish mechanical
support for the moss, the water and salts necessary for the life of the plant being
absorbed exclusively by the scale-covered leaves. A sufficient amount may
be obtained from three hours dew or rain to last the plant for 38 hours. The
leaves are well supplied with chlorophyll in minute oblong plastids, and the
complete independence of the plant is shown not only by the entire absence of
any organic connection with the living tissues of the host, but also by the fact
that it thrives upon old board fences and even upon electric wire insulators.
It seems to thrive best in semi-arid conditions. Shade trees may be freed
from the epiphyte by scraping off the larger plants before the dissemination of
17 BrrceE, Witte I., The anatomy and some biological aspects of the “ball moss,’
Tillandsia recurvata L. Univ. Texas Bull. 194. pp. 24. pls. 10. 1911.
1912] ‘CURRENT LITERATURE 263
the seed in January, and by the destruction of the seedlings by spraying with
a 10 per cent kerosene emulsion.
The study of the morphology of the reproductive organs shows a single
archesporial cell giving rise to a parietal cell, which BILLINGs says does not
appear in 7. usneoides. In four or five days after formation the megaspore
mother cell begins the divisions that result in a linear tetrad; an embryo sac
of the usual type is produced; double fertilization commonly occurs, and the
endosperm develops as free nuclei which eventually line the sac and become
separated by walls. The development of the embryo is of the usual Alisma
or Sagittaria type characteristic of most monocotyledons. The dispersal of the
seeds is facilitated by long barbed hairs arising from the integument, and later
functioning in attaching the seeds to the substratum, upon which they speedily
germinate. Under favorable conditions germination frequently occurs within
the capsule before the dispersal of the seed.—Gro. D. FULLER.
ermeability.— Heretofore the power of various anilin dyes to stain living
plant cells has been tested on algae, water plants, root hairs, or thin sections of
organs of land plants, a method introduced by the pioneer work of PFEFFER.
Kister® conceived that surface cells as used in this method may have different
permeability characters from the deeper placed ones, also that cells of land
plants may have their permeability characters considerably altered by section-
ing. In order to test the ability of anilin dyes to penetrate the deeper lying
cells in their natural conditions, Kiisrer used twigs of some size, or at least
whole leaves with petioles. The cut ends were placed in aqueous solutions of
the dyes, which were carried up the xylem by the transpiration stream, and,
after 24 hours sections of the organs were studied for staining of the living cells
along the xylem strands. A number of anilin dyes that former workers have
pronounced incapable of entering living cells Kister finds by this method to be
excellent intravitum stains. He distinguishes carefully between true intra-
vitum staining and staining due to injured protoplasm. In many cases cells
were not injured by many days’ treatment with dyes, and dyes abundantly
stored in living cells were not reduced in amount by several days’ washing in
running water.
His results furnish much evidence against OvERTON’s lipoid theory of
permeability; and in contrast to the results of RUHLAND on plant cells and
H6BER on animal cells s, show, with few exceptions, a general parallelism
between high diffusibility taan-colicidaliey) of the aqueous solution of anilin
dyes and their ability to penetrate the living cell —WILLIAM CROCKER.
Chemical unit-characters in maize.—While all inherited characters are
probably referable to chemical relations brought about in the segregations and
recombinations of the substance and substances of the germ cells, little atten-
Wararess eee
* Kuster, Erwsr, Uber die Aufnahme von Anilinfarben in lebende PA n
Jahrb. Wiss. Bot. 50: 261-288. ro11.
264 BOTANICAL GAZETTE [SEPTEMBER
tion has been given thus far to the invisible chemical composition of, zygotes
L
determine the externally distinguishable characters of color and starchiness.
As the method of arriving at this conclusion was indirect, it was impossible
to determine whether these chemical characters are also independent of each
other. The low grades of all these characters are dominant over high grades.
The authors assume that the absence of the genes for starchiness (ss) acts as
an inhibitor to these chemical units. It would harmonize better with the
presence-and-absence hypothesis to regard the low grades of the various
chemical substances here considered as the product of the interaction of the
corresponding genes with the gene for starchiness. The authors point out
that the result of this investigation should lead to a revision of the usual
interpretation of the oft-cited selection experiments of the Illinois Agricul-
ural Experiment Station—Gero. H. SHULL.
Transition from root to stem.—Compron” has published a very
useful analysis of the theories of the anatomical transition from root to stem.
Its text is the recent notable publication by Caauveaup which Comen®
regards as marking “‘an important advance in the study of seedling anatomy.”
In these days, when many botanists are trying to orient themselves in the
very rapidly developing field of vascular anatomy, such comparative state-
ments are very helpful.—J. M. C
Embryogeny of Ranunculaceae.—Sovices has undertaken the
investigation of the embryo sac and embryo of the Ranunculaceae, and the
papers dealing with the Clematideae were noticed in this journal.™
four most recent papers in the series” continue the sitcbeoa tial of er
Anemoneae, and comprise a detailed account of Myosurus minimus. It
interesting to have the — of this form so thoroughly worked out ee
so well illustrated.—J. M
oO
Ps £ otnin chemical
9 PEARL, R., and Barttett, J. M., The Mendeli
characters in maize. Zeitschr. Ind. Abst. Vererb. 6: 1-28. st 7, 191i,
c . H., Theories of the anatomical transition from root to stem.
New Phytol. sa: 13-25. he I. 1912.
3t Bot. Gaz. 512480. rorr.
22 Sources, E., Recherches sur |’embryogénie des Renonculacées. Bull. Soc.
Bot. France 58: 542-549, 629-636. 1911; 59223-31, 51-56. 1912
Vol, LIV z : No. 4
THE
BoTANICAL GAZETTE
October ror2
Editor: JOHN M. COULTER
CONTENTS
Comparative Anatomy of Dune Plants Anna M. Starr
Parnassia and Some Allied Genera Lula Pace
Development of the Microsporangia and Microspores of
Abutilon Theophrasti V. Lantis
Briefer Articles .
Artificial Production of Aleurone Grains ~ W. P. Thompson
Current Literature
The University of Chicago Press
CHICAGO, ILLINOIS
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— THE MARUZEN-KABUSHIKLKAISHA, Tokyo, a Kyoto
Che Botanical Gazette
H Monthly Fournal Embracing all Departments of Botanical Science
Edited by JoHN M. CouLTER, with the assistance of other members of the botanical staff of the:
University of Chicago,
Issued October 15, 1932
Vol. LIV CONTENTS FOR OCTOBER 1912 No. 4
COMPARATIVE ANATOMY OF DUNE PLANTS. ConrrisuTIONs FROM THE HULL Botan =
CAL, LABORATORY 261 (WITH THIRTY-FIVE FIGURES). Anna M. Starr - - - yi tiasd oa
PARNASSIA AND SOME ALLIED GENERA (wir PLATES xIv-xvil). Lula Pace - = 306. :
DEVELOPMENT OF THE MICROSPORANGIA praeets Seca ross OF eee
HEOPHRASTI (with ge doa svar Song ah VY. Lont
BRIEFER ARTICLES 3
: DENOLAS PRODUCTION OF ALEbRoNE Grats (WITH ONE FIGURE). W.P.Thompson - 336
CURRENT LITERATURE
bg v NODES POR. STUDENTS = pe 8 ee oe ee ee
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VOLUME LIV NUMBER 4
SA
BOTANICAL GAZETTE
OCTOBER rg12
COMPARATIVE ANATOMY OF DUNE PLANTS
CONTRIBUTIONS FROM THE HULL BOTANICAL LABORATORY 161
ANNA M. STARR
(WITH THIRTY-FIVE FIGURES)
The Hiteratiste of ecological anatomy is extensive when one con-
siders that the whole subject of ecology is a late arrival in the field
of botany. Comparative anatomy, ecologically viewed, is limited
enough to justify a brief review. BONNIER (I) was a pioneer in
experimental work, taking parts of plants growing in intermediate
situations in the mountains and transplanting one part to the low-
lands and another part to alpine conditions. He found that the
plants grown in the two habitats differed in appearance, habit, and
structure (2). GREVILLIUS (15) in an extensive work on the island
Oland compared the vegetation of the alvar, a dry, rocky, treeless
plain, with that of the fertile regions. CHRYSLER (7) compared the
anatomy of strand plants at Woods Hole with that of the same
species growing on the shores of Lake Michigan. CANNON (5) at
the Desert Laboratory (Tucson) contributed some experiments on
desert plants, keeping some plants under irrigation and letting
others of the same species grow without irrigation, his study being
a comparison of the conductive tissues. CHERMEZON (6) in a
recent contribution to the anatomy of littoral vegetation makes
some comparison of it with that of continental plants. All agree
that the structure of plants varies with change in conditions.
In 1899 Cowes (8) published the results of his studies of the
sand dunes of Lake Michigan, describing the general features of
265
266 BOTANICAL GAZETTE [OCTOBER
the coast, the ecological factors, and the plant associations. It was
his intention to enter into an investigation of the anatomical rela-
tions of the plants described, but other work prevented. In the
fall of 1908 he suggested that I undertake the study, and it has been
under his direction that the work has been carried on. I wish to
express my grateful thanks to him and to all the members of the
Department who helped me with criticism and advice, and also to
those who aided me in photographic work and in collecting material.
In 1904 C. L. HorrzMan, in an unpublished dissertation, described
the leaves of six of the species included in my work, and I have had
access to his paper.
The dune plants were collected from the Indiana dunes, chiefly
from the vicinity of Miller’s, Dune Park, and Furnessville. The
mesophytic forms came mainly from the flood plains of the
Desplaines River at Riverside; some were collected in other meso-
phytic woods in the same general locality, while a few came from
the Mississippi flood plain.
The stems and roots were preserved in formalin and 50 per cent
alcohol and cut with a hand microtome. The leaves that made the
most successful permanent preparations were killed with corrosive
sublimate dissolved in g5 per cent alcohol, used hot. These were
easily sectioned in paraffin. I found 8 the most satisfactory
thickness. Free-hand sections were also made. Safranin and
anilin blue were used in staining. The names are those given in
the seventh edition of Gray’s Manual and differ therefore at times
from those used by Cow.es. The drawings were made by the
aid of a camera lucida, magnified 470 diameters, and reduced one-
half in reproduction.
Ecological factors in the dunes
LicHt AND HEAT.—There is direct illumination, increased by
reflection from the sand. Because of the scanty vegetation and the
great exposure, the temperature of the air is higher in summer and
lower in winter than in more protected localities. Owing to the
high conductivity of sand, the same great divergence between
extremes is present in the temperature of the soil.
Winp.—Cow1Les considers this the most potent factor in
determining the character of the dune vegetation. The winds
1912] STARR—ANATOMY OF DUNE PLANTS 267
gather force as they sweep across the lake, and when they reach the
shore they gather up sand and carry it along with a force that
carves and scars the bark of the trees on the windward side or
completely wears it away, as in the case of Cornus stolonifera.
Soit.—The soil is chiefly quartz sand, the particles being
relatively large, so that it is extremely porous, which has a great
influence on the water and heat relations. As a rule sandy soils
are poor in nutrient food materials, nor do they rapidly develop a
rich humus because of the rapid oxidation of the organic matter.
Water.—The surface layer of soil is very dry, as the capillarity
of sand is less than that of other soils, evaporation from a sandy
surface is rapid, and precipitated water percolates quickly, the
water capacity of sand being slight. On the other hand, a sandy
soil yields its water to plants more freely than other soils, and below
the superficial layer of dry sand there is always a surprising amount
of water. FULLER (13) has found this to be more than double
the wilting coefficient of dune soil.
Biotic racrors.—The only biotic factors of marked influence
in the dunes are those associated with the plants themselves when
they are once established, humus and shade. Humus influences
the temperature of the soil and increases the water content, the
number of soil organisms, toxicity, and aeration. Shade influences
the germination of seeds and increases the accumulation of humus
and atmospheric humidity, and so decreases evaporation. FULLER
(12) finds that in the cottonwood dunes the evaporation is 21 cc.
per day, while on the pine dunes it is 11 cc., in the oak dunes ro cc.,
and in the beech-maple forest 8 cc., a descending scale from the
Ploneer formation to the climax forest.
Description of the plants
I. XEROPHYTIC FORMS
Herbs
Cakile edentula.—A small, very succulent annual. Leaves
Smooth and thick; outer walls of epidermis 4; several rows of
Palisade on each side with a narrow zone of sponge in the center;
Water-storage tissue about the bundles; stomata on both surfaces;
conductive elements not well developed. Stem with epidermal
walls thickened al] around, the outer 10 #.
268 BOTANICAL GAZETTE [OCTOBER
Euphorbia polygonifolia.—A little prostrate succulent annual
with abundant latex. Leaves small, thick, inclined to be folded
at right angles on the midrib; walls of epidermis thickened, outer
g-12 on the upper surface and 15 at the edges of the leaf;
stomata sunken to the depth of the epidermis; a layer of palisade
cells next the upper epidermis and “‘festoon”’ palisade about the
undles; a layer of water-storage tissue next the lower epidermis;
cells at the bend of the midrib collenchymatous; small develop-
ment of vascular elements. Stem woody for so small a plant,
having a compact vascular cylinder; walls of epidermis thick,
outer 8 #, cuticle 4.6; cells below thickened; latex tubes con-
spicuous.
Corispermum hyssopifolium.—Low, branching, succulent annual.
Leaf thick, narrow, linear; two layers of palisade on both sides
and water-storage tissue in the center; walls of the epidermis
thickened, outer 16 #; cells with thickened walls about the midrib
at the edges of the leaf. Stem with two layers of palisade in
the cortex and collenchyma at the surface; walls of epidermis
heavy, outer 9.6#. Root sclerenchymatous except a few outer
layers.
Artemisia caudata and A. canadensis.—Stout, bushy biennials
or perennials. Leaf. divided, divisions thick, smallest almost
cylindrical, generally pubescent; double row of palisade on both
surfaces, water-storage tissue inside; walls of epidermis thickened,
outer wall 6-11; stomata sunken one-half the depth of the
epidermal cells. Stem with pith rapidly. reduced after the first
year, small in older, a dense cylinder of wood extending almost to
the center; great masses of fibers capping the phloem; outer layers
of cortex collenchymatous; considerable cork.
Cirsium Pitcheri—Biennial, tomentose. Leaf very thick, with
revolute margins; epidermal cells small, with thickened walls, -
outer 6.4; chlorophyll confined to 2-4 outer layers of cells; the
rest. water-storage tissue with cells increasing in size toward the
center with large air spaces between. Stem generally hollow,
cortex thick, bundles few, with large vessels and masses of heavy
fibers; rays wider than the bundles, the cells with thickened walls,
outer cells of cortex collenchymatous.
Igt2] STARR—ANATOMY OF DUNE PLANTS 269
Lathyrus maritimus.—A smooth trailing perennial herb. Leaf
with palisade occupying almost half of the mesophyll, the sponge
tissue rather compact; fibers above and below the bundles. Stem
sharply angled; phloem capped by a heavy crescent of scleren-
chyma; a second ring of sclerenchyma penetrating a distance
between the bundles; medullary rays thin; outer wall of epidermis
6.2. Root with large vessels; about one-half the pith made up
of scattered masses of sclerenchyma.
Ammophila arenaria.—A stout perennial grass with firm creep-
ing rootstocks that anchor the dunes. Leaf with morphologically
upper surface rolled in; the surface a series of ridges and grooves;
bundles under the ridges; edges of the leaf and ridges strengthened
with hypodermal sclerenchyma, that in the ridges extending into
the bundles; upper epidermal cells large and globular, or prolonged
into conical hairs; stomata on the upper surface sunken to the
depth of the epidermal cells; chlorenchyma reduced to strands
each side the bundles; air spaces very small; outer wall of the
lower epidermis (the exposed side) 6.4 # thick, the cuticle 3.2 u.
Stem with cortical tissue sclerenchymatous; walls of the epidermis
slightly thickened all around.
Andropogon scoparius (bunch-grass).—Leaf stiffened with a
Series of bundles, large ones alternating with three small ones, the
Space above the small ones filled in with three or four enormous
epidermal cells and smaller, hypodermal, colorless cells; epidermal
cells occasionally prolonged into sharp hairs, longer than those of
Ammophila; the large cells collapse at the bend of the leaf, as it
folds with the upper surface in; masses of sclerenchyma above
and below the large bundles and below the middle of the small
ones; chlorenchyma above the bundles; outer wall 9.3 #; cuticle,
thick; stomata on lower surface not sunken.
Calamovilfa longifolia.—A rigid perennial grass with horizontal
rootstocks and pubescent sheaths; another dune former. Leaf with
lower surface plane; with ridges and narrow depressions on the
upper surface which rolls in as in Ammophila; walls of epidermis
thick, cuticle thick; bundles in the ridges with sclerenchyma above
and below, and sometimes about the phloem; hypodermal scleren-
chyma next to the lower surface and at the top of the ridges; short,
270 BOTANICAL GAZETTE [OCTOBER
pointed hairs’on the upper surface; chlorenchyma, a layer of pali-
sade, and a layer of spherical cells about the bundles; walls of
parenchyma cells sometimes folded in as in Pinus; stomata sunken
as in Ammophila. Stem with bundles more numerous toward the
periphery, where the cells of the fundamental tissue become
smaller; epidermal cells very small.
Solidago racemosa Gillmani (fig. 1).—A perennial herb, woody
at the base. Leaf with outer wall of lower epidermis 8 » thick,
cuticle 2.4 #; chlorenchyma above
and below; water-storage tissue in
i , the center; chlorenchyma above
Ne URE ue
. , 3 Ly D de Ah > o
§
Q scarcely palisade-like, but of two
OU a or more layers of slightly elongated
cells forming a compact tissue;
good development of bundles in
the midrib. Stem with small pith;
cortex thick, containing groups of
fibers and occasionally sclereids,
outer layers collenchymatous;
crystals in the cells of the pith.
Root with ground tissue of scle-
renchyma; outer cells of cortex
collenchymatous.
a racemosa Giill- Lithos permum Gmelini.—A per-
ennial herb clothed with bristly
hairs. Leaf thick, coarse, rough on both surfaces, with appressed
hairs, bent upward at the midrib; outer wall of epidermis thick
on both surfaces, 9.3; palisade next both epidermal layers made
up of a row of long cells, or of two rows of shorter cells; three layers
in the center almost colorless; stomata not sunken. Stem with a
small solid cylinder of wood made up chiefly of fibers, the vessels
large; outer layers of cortex slightly collenchymatous; outer wall
of epidermis 5» thick.
Arenaria stricta.—A low, tufted herb. Leaf smooth, needle-
like; epidermal cells enormous, thickened on all sides especially at
the edges of the leaf; outer wall 3.2-7 #; cuticle thick; scleren-
chyma below the bundles; whole mesophyll composed of compact
tissue; no palisade; crystals frequent.
Fy
mani: section of leaf,
Igt2] STARR—ANATOMY OF DUNE PLANTS 271
Opuntia Rafinesqui.—Stem doing the chlorophyll work; outer
wall of epidermis 8 thick, cuticle 2.4; several hypodermal
layers of small heavy-walled cells; the chlorenchyma composed
of many layers of cells elongated perpendicularly to the surface;
the center of the stem occupied by a loose tissue of large colorless
cells, the whole retaining water so effectually that it is difficult to ,
dry it out even with heat and pressure; vascular system poorly
developed; walls of the elements thin.
Shrubs
Prunus pumila.—A low shrub spreading easily in all directions
and thus important in helping to make dunes stationary. Leaf
thick, 2164; outer wall of epidermis 5-6 #; cuticle very thick,
ridged on the lower surface, the ridges so high that they fray out
along the edge; cells above and below the midrib papillate and
cuticle smooth, 8 ; heavy masses of collenchyma above the stele of
the midrib and several layers below, also in other large veins; great
development of conductive elements; palisade double and festoon
palisade above the bundles in the veins; lower cells of mesophyll
palisade-like; crystals, oil, and other deposits abundant. Stem
with vessels large and generally numerous; wood fibers heavy, with
small lumen; groups of sclerenchyma in the cortex; cork thick. —
Salix syrticola.—A shrub with the same habits as Prunus pumila.
Leaf with upper surface silky, lower hairy, closely serrate, glandular;
stipules large; outer wall of upper epidermis thick; heavy scleren-
chyma above and below the stele of the midrib, and collenchyma
next the epidermis on both sides; two layers of palisade next the
upper epidermis and three more layers elongated vertically. Stem
with medullary rays very narrow; ‘vessels not large but numerous;
fibers heavy, with small lumen; outer layer of pith sclerenchyma-
tous; outer layers of cortex collenchymatous; three rows of mechani-
cal fibers in the cortex, the outermost very wide.
Hudsonia tomentosa.—A bushy, heathlike shrub. Leaf small,
awl-shaped, hairy on both surfaces and especially along the edges;
upper epidermis composed of large cells; palisade about one-half
the mesophyll of the narrow part of the leaf. Stem hairy, very
woody, the vascular cylinder occupying most of the diameter, com-
posed of very heavy fibers and few vessels; a few large scleren-
272 BOTANICAL GAZETTE [OCTOBER
chymatous cells form the pith; a few rows of cells, part of them
fibrous, form the cortex.
Arctostaphylos Uva-ursi.—A woody little plant trailing over the
ground. Leaf thick, smooth, evergreen; outer wall of epidermis of
both surfaces thick, cutinized; side walls plane, cutin sometimes
16 # thick; upper epidermis sometimes divided periclinally; bundles
compactly developed, with fibers above and below ; collenchyma
next the epidermis; palisade several rows of shorter cells or two
rows of longer; all mesophyll cells elongated perpendicularly to
the surface; stomata sunken one-half
the depth of the epidermal cells. Stem
with xylem cylinder very woody; walls
of pith and medullary ray cells heavy;
cortex and phloem zones very narrow;
cork layer not strikingly thick but very
dense; 9 years’ growth in a stem 4 mm.
in diameter.
Juniperus communis (fig. 2).—An erect
evergreen shrub. Leaf thick, rigid, con-
vex on one side, concave on the other
which is the morphological upper side
and is most protected when the leaves
2.—Juniperus com- are appressed to the stem; stomata on
this side at the base of the epidermal
cells, guard cells with thickened walls; outer and side walls of
epidermis thick, outer 11-13» with cuticle 3.2; hypodermis
heavy; resin duct on convex side. Stem with almost no pith
and heavy wood cylinder; 13 years’ stem 4 mm. in diameter;
cork thick.
Juniperus virginiana.—A shrub or small tree. Leaf awl-
shaped; outer wall of epidermis very heavy, 9.6», cuticle 4.8 #5
two or three hypodermal layers on the convex side of the leaf
heavily thickened; sunken stomata on upper plane surface, the
protected side when the leaf is appressed. Stem with solid mase
of heavy-walled tracheids and almost no pith; 11 growth rings in 4
stem 4.5 mm. in diameter; rows of sclereids in the cortex; cork
thick.
Fic.
munis: section of leaf.
1912] STARR—ANATOMY OF DUNE PLANTS 273
Hypericum Kalmianum (fig. 3).—A bushy shrub. Leaf revo-
lute, thick, leathery; outer wall of epidermis 4.8 #, cuticle 2.4 4,
lower epidermal cells inclined to be papillate; double palisade;
stomata sunken the depth of the epidermis. Stem with vessels
large, fibers heavy, lumen small; pith small, cork thick; three
growth rings in a stem 3 mm. in diameter.
Trees
Pinus Banksiana.—Leaf shorter and thicker than in most pines;
walls of epidermis heavy; outer 8 #, cuticle 1.8; hypodermis
also heavy; thickness of both increased at the edges of the leaf;
outer wall of endodermis thickened
and lignified; mesophyll cells with
infoldings in the walls; stomata
deeply sunken, with an outer and
inner vestibule and with walls 3.2
thick; two resin ducts. Stem with
small pith; woody cylinder large,
composed of a solid mass of tra-
cheids with very thick walls.
Quercus velutina——Small-in
comparison with many oaks, and
of rather scrubby growth. Leaf
thick, having a brilliantly varnished
surface; sclerenchyma around the bundles of the midrib; cells
above and below collenchymatous; epidermal cells over midrib
papillate; outer wall of upper and lower epidermis thickened,
cuticle thick; palisade double. Stem with pith star-shaped; vessels
large; fibers heavy, with small lumen; medullary rays narrow, pith
sclerenchymatous ; an irregular band of fibers in the cortex.
Fic. 3.—Hypericum Kalmianum:
section of leaf.
Summary of xerophytic characters
The true dune plants have the following characteristics, which,
with the exception of the characters of the conductive system, are
generally admitted to be xerophytic:
BIT.—Low, tufted, or bushy, with short internodes (Avenaria,
Artemisia, Hudsonia, Juniperus communis, J. virginiana); low
274 BOTANICAL GAZETTE [OCTOBER
and spreading (Prunus pumila, Salix syrticola); low and trailing
(Lathyrus, Arctostaphylos); low, with underground, creeping
rootstocks (Ammo phila, Calamovilfa).
LreaF.—Small and awl-shaped (Arenaria, Hudsonia, Juniperus
communis, J. virginiana); longer, sometimes wide but thick
(Artemisia, Ammophila, Calamovilfa, Lithospermum, Prunus, Arcto-
staphylos, Pinus, Hypericum, Cakile, Quercus, Corispermum);
evergreen (Arctostaphylos, Juniperus communis, J. virginiana,
Pinus); folded or revolute (Cirsium, Ammophila, Calamovilfa,
Lithospermum, Hypericum, Euphorbia polygonifolia); succulent
(Cakile, Euphorbia polygonifolia, Corispermum, slight in Artemisia,
Cirsium, Solidago); hairy (Artemisia, Cirsium, Lithospermum,
Salix syrticola, Hudsonia); equilateral (Cakile, Corispermum,
Artemisia, Cirsium, Lithospermum).
ANATOMY OF LEAF.—Outer wall of epidermis thick (Cakile,
Euphorbia polygonifolia, Corispermum, Artemisia, Cirsium, Am-
mophila, Calamovilfa, Andropogon, Solidago, Lithospermum, Are-
naria, Prunus pumila, Salix syrticola, Arctostaphylos, Juniperus
communis, J. virginiana, Pinus Banksiana, Hypericum, Quercus
velutina, Opuntia); cuticle thick (Ammophila, Calamovilfa, Andro-
pogon, Solidago, Arenaria, Prunus’ pumila, Arctostaphylos, J untp-
erus communis, J. virginiana, Pinus Banksiana, Hypericum,
Quercus, Opuntia); deep, compact palisade accompanied by few
air spaces in sponge (Artemisia, Lathyrus, Lithospermum, Prunus
pumila, Salix syrticola, Hudsonia, Arctostaphylos, Hypericum,
Quercus velutina, Cakile, Corispermum); stomata sunken (Arte-
misia, Ammophila, Calamovilfa, Hypericum, Euphorbia polygont-
folia, Arctostaphylos, Juniperus communis, J. virginiana, Pinus);
conductive tissue well developed (Solidago, Prunus, Arctostaphylos) ;
mechanical tissue present as sclerenchyma (Lathyrus, Ammophila,
Calamovilfa, Andropogon, Salix syrticola, Arctostaphylos, Quercus),
as collenchyma (Solidago, Andropogon, Prunus, Salix syrticola,
Arctostaphylos, Quercus, Euphorbia polygonifolia).
ANATOMY OF STEM.—Succulent (Opuntia); conductive tissue
well developed, with vessels large (Cirsium, Lithospermum, Prunus,
Hypericum, Quercus), with vessels numerous (Salix syr ticola,
Prunus pumila); mechanical tissue present, an abundance of w
1912} STARR—ANATOMY OF DUNE PLANTS 275
fibers giving general ‘“woodiness” (Euphorbia polygonifolia, Arte-
misia, Cirsium, Lithospermum, Prunus, Salix syrticola, Hudsonia,
Arctostaphylos, Pinus, Hypericum, Juniperus communis, J.
virginiana, Quercus), as sclerenchyma (Artemisia, Lathyrus, Am-
mophila, Solidago, Prunus pumila, Salix syrticola, Hudsonia,
Quercus, Juniperus virginiana), as collenchyma (Artemisia, Cirsium,
Solidago, Lithospermum, Salix syrticola, Pinus, Corispermum);
outer wall of epidermis thick (Cakile, Euphorbia, Lathyrus, Ammo-
phila, Lithospermum); cork thick (Artemisia, Prunus, Hypericum,
Juniperus communis, J. virginiana).
NATOMY OF ROOT.—Sclerenchymatous generally (Cakile, Cori-
spermum, Lathyrus, Solidago); collenchyma in cortex (Solidago);
crystals abundant (Solidago, Arenaria, Prunus); resin (Juniperus
communis, J. virginiana, Pinus); latex (Euphorbia); perhaps none
but the last is related to xerophytic conditions.
Slowness of growth is shown by the large number of growth
rings in stems of small size (Arctostaphylos, Hypericum, Juniperus
communis, J. virginiana), testifying to adverse conditions. Suc-
culency usually excludes some other factors, as hairiness and good
development of conductive elements.
Firrinc (11) has recently shown that desert plants apparently
do not need longer roots to reach an abundant water supply, as
they have a most effective means of obtaining it from a very
scanty supply in the high osmotic pressure of their cell sap. Dune
plants have not been examined in this respect. It may be found
that they too have this “adaptation” to xerophytic conditions.
II. ComparisoON OF PLANTS GROWING ON THE DUNES WITH THE
SAME SPECIES GROWING IN MESOPHYTIC SITUATIONS
The purpose of this part of the investigation was to find out
by careful measurements just how much variation there is in species
found in two widely differing habitats. The measurements of
sections were made with a micrometer divided into 100 spaces.
For the measurement of the leaf, sections were made near the
middle, cutting straight across the midrib; an average was taken
of several measurements of one leaf and then of several leaves. For
276 BOTANICAL GAZETTE [ocTOBER
the study of the conducting and mechanical tissues of the leaf, a
section of the midrib was taken at the base of the blade. For the
study of the stems, sections 5 mm. in diameter.were used; when
‘this was not possible, the two compared were as nearly equal as
obtainable. CANNoN’s method of counting was adopted. A circle
14cm. in diameter was drawn on paper and octants were marked
off. With a camera lucida an image of the section was so thrown
on the paper that the arc of the octant coincided as nearly as pos-
sible with the periphery of the wood cylinder. The area of the
octant was 18.24 sq.cm. (147X0.7845+8). Since the magnifica-
tion used was 100, the area examined was 0.19 sq. cm. or 19 Sq. mm.
For the size of the vessels and fibers measurements were always
made in the last spring wood, or if that was not fully organized, in
the preceding. In the following tables M stands for the mesophytic
form and X for the dune form; T for the average thickness of leaf,
with minimum and maximum in parenthesis; UE for thickness of
the upper epidermis, including cuticle; P for depth of palisade;
Sp for depth of sponge; LE for thickness of lower epidermis; OW
for outer wall of the epidermis (including cuticle); and Cw for
cuticle. The percentages are of the entire thickness of the leaf. In
the table of stems V stands for the number of vessels in the octant;
D for the average diameter of the larger vessels, with the maximum
in parenthesis; W, the thickness of the walls of the vessels; F, the
thickness of the walls of the fibers; L, the lumen of the ‘fibers; R,
the number of growth rings; C, the thickness of cork; and S, the
thickness of the sclerenchyma ring or of the isolated masses of
sclerenchyma that often appear in the cortex. As the size of
vessels, being tubes, varies as their cross-sections and as the cross-
sections vary as the squares of their radii, it is evident that the ves-
sels in an octant of a mesophytic form would compare with the
vessels in an octant of the corresponding dune form as the products
of the number of vessels by the squares of their radii. Where the
result is not evident at a glance, the radius was squared and the
product found. The measurements are all in microns, though the #
is omitted after the first, as is also the per cent sign.
1912] STARR—ANATOMY OF DUNE PLANTS 277
Trees
ACER SACCHARUM
Leaf : Stem
M xX M Xx
T..... 75 (69-93) 103 & (95-109) Ni... 4% 33
UE... 10.5 =14percent 13 =12 percent ay. sae. SG) ay ee)
Pee. 5 49.5 =39 40 =30 Ae 3-5
Sp.... 29.0 =39 40 =39 ; 4.2 4-7
LE... 6.0 = 8 Io =I0 bos O86 8.5
wy... *.6 4:5 R... 3-5 2-4
Cu... thin r.7 one 72
re 50
X.—Hairs on lower surface; upper Tn all points but the thickness of the
epidermal cells smaller in depth, slightly walls of the vessels and the fibers, an
larger in surface extent; outer wall and exception to the majority of cases
cuticle thicker; sclerenchyma around the examined.
bundles of the midrib heavier; greater
development of bundles; cuticle on
upper surface more strongly ridged. In
both stomata on lower surface only.
CELTIS OCCIDENTALIS
Leaf Stem
M § M x
T..... 65 4 (87-72) 120 @ (104-144) NXg 18.5
UE: .. 13 =20 per cent 24 =20 per cent D... 74 mw(tor) 74 # (120)
1 SOS I4 =22 43 =36 W.-. 22 3.2
ae = 37 40 =33 Foo a8 6.4
LE... 14 =ar 13 11 L 4.8 ee
OW... oF 3 Ae: 7
Cu... very thin 0.7 Ca: §e 32
Sivan O84 80
X.—Large glandular cells frequently X.—A straggling shrub, probably var.
occupying the place of the epidermis and pumila; slightly greater development of
Palisade; collenchyma below and scle- vessels with heavier walls; fibers heavier,
renchyma above the midrib, where neither but fewer of them than in M, replaced by
appears in the mesophytic form; greater tracheids; cork thinner; more scleren-
development of vascular elements.— chyma in the cortex.
Figs. 4 and s.
278 BOTANICAL GAZETTE [OCTOBER
FRAXINUS AMERICANA
Stem
M 7
T.....142 « (124-159) 162 « (142-187) Nee 24.5 19.5
UE... 11 = 8 percent 14 = gpercent DD... 5e w (87). St 8Ge
Po. 552: 36 6 2 Won a 9
Sp. 68 =48 59 =36 Eo... 32 4.5 a
BAS OPN ea 2I =13 i 7.4 (ee
OW, hs 3 R 88 110
Cu. 0.7 1.8 2 53 99
S 3-5 I-2
X.—Epidermal cells of greater depth; X.—Differing from the majority in
outer wall and cuticle thicker, ridged in number and size of vessels and more
the lower epidermis, most of the cells of rapid growth; walls of vessels and fibers
the lower epidermis produced into short thicker; sclerenchyma and cork heavier.
conical hairs, the rest into — ce In both walls of pith-cells thickened with
(M smooth); all tissue more co conspicuous canals, and outer cortex
palisade deeper, tending to devebo ae collenchymatous, features pronounced in
ae
i ii ‘VY Yt wah
Hi iN KK i +
j J ,
\ ” VW Cav
NTN
} I fe i WY
Shee
we
wos soot
IY Saat
: raMSF EV WS
; x MD Dh ¥
t Bh ik
‘aT
0 RAR
DRYAS I AR
(A
i )
Me }
ge if
Fics. 4-7.— Figs. 4 and 5, pe occidentalis: sections of leaves; fig. 4, mesoph,
form; fig. 5, dune form; figs. 6 7, Fraxinus americana: sections of leaves; “fg. 6
mesophytic form; fig. 7, dune ca
1912]
X.—More pubescent; upper epidermal
cells smaller in depth, sa
extent; first layer of palisade deeper and
a second layer developed; vessels in mid-
Fics, % 0.
dune form
STARR—ANATOMY OF DUNE PLANTS
M
- 92 (79-112)
I2 =13 pe
2I =21
44 =48
14 =16
thin
279
JUGLANS CINEREA
Xx
148 mw (119-166)
I3 = g percent
8 lores
82 =55
14 =I10
3-7
me in surface
©
Stem
Ni sas 25
Dons tg wm Ss) 5s a Ge)
Wee 3-8
Bo Sk 3-2
i: Gus 9
R 1-6 (av.3) . i3
G 60 57
wets a7
X.—Like the majority in the greater
number of vessels of smaller area (but the
final product — the smaller lumen
of the fibe _the heavier scle-
renchyma ~ differin n thinner walls and
cork, and: cocsdnatslig large number of
rings produced in M
ie
—Juglans cinerea: sections of leaves; fig. 8, mesophytic form; fig. 9,
280 BOTANICAL GAZETTE [OCTOBER
LIRIODENDRON
Leaf Stem
M xX M
T.....148 4 (137-168) 210 M (190-236) No 90 131
UE... 1§ =10 per cent 17 = 8 percent D... 34 #48) 32. ete
se 37 =25 59 =28 Wiest. ee
Sp 80 =54 IIl =53 Bey ceo es 4.6
| pee to ee 22 =11 i 10-7 8.5
Ow. $3 5.6 KR. aS 2-5
Cu 2 c: 42 5°
S
X.—Cells of upper epidermis smaller Like the majority in all respects. In
in surface and depth, side walls plane both, sclerenchyma around the pith and
(wavy in M); palisade deeper, sometimes groups of fibers capping the phloem.—
of more layers; cells of upper layer each Figs. 12 and 13.
side of midrib larger than others and
without chloroplasts, as if a secondary
epidermis; vessels more numerous in
midrib; greater masses of fibers and
more collenchyma. In both, lower epi-
dermis heavy.—Figs. ro and 11.
an
As
ome
Y
ah
ij
(A)
ae 9
A n Y
DY ¥
W Oe W
at)
une
stems; fig. 12, mesophytic form; fig. 13,
e form.
1912] STARR—ANATOMY OF DUNE PLANTS 281
OSTRYA VIRGINIANA
Leaf Stem
M xX
T..... 78 (66-9 110 # (gI-125) Ns 24
UE. ¢ 10 =11 a cent II =10 per cent jp is #(75) 26 # (37)
| ae 30 =38 43 =30 w.. 2.8 ee
Sp..:.. 32 45 F.... 23:3 3-9
Leos 6 II 7 6.7 5.6
We. 4.3 3.2 - = 3-6
Es. 64
X.—Upper epidermis slightly thicker
and wall thicker; little variation in the
depth of the palisade, but the layer more
compact; stomata on lower surface only
(in M occasionally on the upper).
X.—Rings of sclerenchyma in the
cortex wider and outer layers of the
pith more sclerenchymatous; in all re-
spects, except as to the thickness of the
wall of the vessels, agreeing with the
majority.
POPULUS BALSAMIFERA
Leaf Stem
x. M xXx
ats as 272) 212 @ (195-228) N go
UE... te & cent 17 = 8 percent D 46 @(62) 36 (50)
P.. 36 94 = Ww. 2.9 2.6
Sp... .129 89 ee ce 3.8
LE... 14 16 ee 6.8
Ow. 4-3 5 R I-2 2-9
Cu. r 1.2 Co. 100
cn Oe 90
The only exception found to the general
fact that dune plants have thicker leaves
than mesophytic, per epidermis
and palisade relatively deeper; outer wall
and cuticle thicker and ridged; more ves-
sels in the midrib, larger; more fibers
about the stele. Both have stomata on
both surfaces; all side walls of epidermis
plane except those of lower surface in M;
double palisade.
—Up
X.—Vessels agreeing with the majority
in total area, but walls slightly ig meni
walls of fibers also thinner, but lum
smaller, so the amount of wood may be
the same; cork only starting to form in
BOTANICAL GAZETTE
[OCTOBER
POPULUS DELTOIDES
Leaf Stem
M xX
T.....103 # (177-227) 254 m& (236-295) Nic ao 85
UE... 13 = 7 percent 8 cent D... 49 4 (64) 50 @ (62)
F.. 62 =32 84 =33 Wei, 226 2.7
Sp....105 =54 ¥38 =55 Bevis 9 8 3.9
Boy a4 14 = 5 Lot. 68 6
OW. 273 4 Ryo 2 I-4
Cu 0.8 z. Sa 105
Dei Om 98
In both lower epidermis thickened as
well as upper, stomata on both surfaces
and side walls of epidermal cells plane, all
related to the movement of the leaf.
X.—Upper epidermal cells smaller in
surface; surface slightly hairy; palisade
sometimes triple; also palisade cells near
lower epidermis, separated from it by a
Other points follow the
general rule.—Figs. 14 and 15.
Fics. 14, 15.—Populus delioides: sec-
tions of leaves; fig. 14, mesophytic form;
fig. 15, dune form.
Agreeing with the majority in all
points; a tendency to angled twigs and
star-shaped pith more marked in X.
i
1912] STARR—ANATOMY OF DUNE PLANTS 283
TILIA AMERICANA
Leaf - Stem
M xX M Xx
T..... 90% (90-108) 138 @ (135-156) N
UE... 17 =109 percent 23 =17 percent D 38 (53) 4t m@ (41)
Peeees 26. 26 45 =33 Wo; 2.
Sp 36 =46 52 =38 F. 2.8 2.4
LE... 11 =12 17 LE 9.6 9.1
on... 3% 4.4 Rec. 35 i-§
a... 88 2 C.. 5°
X.—Cells of upper epidermis smaller In both bands of sclerenchyma in the
in depth, larger in surface, sometimes phloem and collenchyma under the
divided periclinally; side walls on lower cork, slightly less in X; little variation
i in walls and a
plane; deeper palisade and tendency __ vessels more numerous and larger in X.
Fics. 16 and 17.—Tilia americana: sections of leaves; fig. 16, mesophytic form;
fig. 17, dune form.
284
BOTANICAL GAZETTE
[OCTOBER
ULMUS AMERICANA
Stem
M x
T.....102 « (94-109) 174 & (164-186) N 28.5 52
UE... 21 =21 per cent 38 =22 percent DD... 6: (tog). 68 2106)
ices 290 =29 70 =40 Wea Sa27 ao
Sp.... 38 =37 51 =20 F. 5.9 Sor
LEV. 13°13 I5 =0 L. 2.9 auF
Wi. 4.2 5.2 Rs. gar 5
Cu...thin thin Gio 66 66
X.—Cells of upper epidermis greater Vessels as in majority. X.—Walls of
in depth; side walls plane, cuticle not
ed (in M walls slightly wavy and
cuticle slightly ridged on lower surface);
i deeper sometimes double, mid-
rib structure as in other X. In both
upper surface rough, hairy (X more so);
some epidermal cells enormous.—Figs.
18 and 19.
-
oe bet)
4 0
=a ~~
ERLE
a) i Gy nt q
wip WD dp Ay \
ti C9
2 Xf
é4
vessels and of fibers very slightly thinner
than in M and lumina of fibers larger, yet
masses of fibers so much more numerous
they form more wood; cork and cortical .
sclerenchyma the same.
‘ ; hytic
Fics. 18 and 19.—Ulmus americana: sections of leaves; fig. 18, mesophyt
form; fig. 19, dune form.
1912] STARR—ANATOMY OF DUNE PLANTS 285
Shrubs
CORNUS STOLONIFERA
Leaf Stem
M a. § M xX
T.....129 » (120-144) 156 mu ING 03 °
UE... 17 =13 per cent 15 =10 per cent D,... 30 & @) 33 #& (45)
P..... 34 =26 48 =31 ae a 4
Sp 56 = 72 =46 Fo ae 5
Dee; ee 21 =13 lacie oe 6.2
VS 86 2 | PA 2-8
Ca) thin 0.8 C.... Noneexcept 112 (in 8-year
at lenticels stem)
X.—Hairs more abundant than in M,
on upper surface radiating from a center
longations of most of the lower epidermal
cells, their cuticle prominently ridged;
walls plane (wavy in
M); deposits in the form of crystals and
oil in the cells, and wax on the outer wall;
other points in most xerophytic
forms.—Figs. 20 and 21.
€
F GS, 20, 21.—Cornus stolonifera:
Sections of leaves; fig. 20, mesophytic
form; fig. 21, dune form.
Epidermal cells when present papillate
and cuticle heavy; cork not formed be-
fore 5 years. In both small groups of
sclerenchyma in cortex. All points as
in majority.
ee a: Oe
16 F top ¥
0 4p Y
b 9 ao do
J
)
9 Al ¥ 9
00
‘
286 BOTANICAL GAZETTE [OCTOBER
HAMAMELIS VIRGINIANA
tem (figs.”22 and 23)
M
N... 94 157
D... 29 #37) 24 oe
Wea 2-4 1.6
Bios ey 6.4
Lis as 656 4
Sa 5
ie. 80 48
Sess Od 88
Fics. 22-25.—Figs. 22 and 23, Hamamelis virginiana: sections of stems; fig. a9
mesophytic form; fig. 23, dune form; figs. 24 and 25.—Prunus virgimiana: sections
of leaves; fig. 24, mesophytic form; fig. 25, dune form.
Igt2] STARR—ANATOMY OF DUNE PLANTS 287
PRUNUS VIRGINIANA
Leaf Stem
M x M
T.....119 # (100-123) 198 @ (187-214) Nin. 96 108
UE... 18 =15 per cent 16 = 8 percent De 2-48 8) 35 (45)
Bie ceg5 3 99 =50 Wo 2.5
Sp.... 51 =43 66 =33 Lee 4.6
LE... 14 =12 17 = 9 he 4.4
Ws... 4.9 6.7 pe ree 3-6
RAL ee 1.8 Goa 61
seek 51
X.—Hairs on lower surface (none in Only exception to the majority rule is
M); cells of upper epidermis larger in the sclerenchyma, which is heavier in
surface, of less depth, cuticle more some mesophytic forms.—Figs. 26 and
prominently ridged than in M; side 27.
walls less wavy; palisade double (some-
times so in M, but cells are not so long
nor sO compact as in X); midrib as in
upper part of palisade; crystals and other
deposits about the bundles.—Figs. 24
and 25.
Re
Fics. 26-27.—Prunus virginiana: sec- * x
tions of stems; fig. 26, mesophytic form; KY
fig. 27, dune form.
288 BOTANICAL GAZETTE
PTELEA TRIFOLIATA
Leaf
T....147 » (131-156)
UE... 14 = 9 per cent
P2242 =20 56 =30
Sp... 78 =53 95 =51
LE... 13 = 9 16 =
OW. 1.2 4.8
Cu ...thin i3
X.—Hairs abundant on lower surface
(none in M); cells of upper epidermis
slightly larger in surface; side walls o
bot d cuticle ridged
M wavy and only sli ghtly ridged);
a mesophytic pocket, had a m
the leaf averaged 210 » in thickne
an outer wall 6.4-8 », heavily sae ny
Fics. 28-29.—Pitelea trifoliata: sec-
tions of stems; es 28, mesophytic form;
fig. 29, dune form
x
185 # (177-193)
8 =10 per cent
[OCTOBER
Stem
xX
News 3 St 51
D... 53 B73). SS) eee
Wee. 22 a5
Bias 2.9
| Pierre ee ae:
Res 2-3 4-7
Cr be 83
Agreeing with the majority, except
that collenchyma in outer cortex may
no heavier in X.—Figs.
28 and 20.
*." *
weeks. ice
ae x
€.0 8
i
5%,
ra%
«
e
"s
é eae
$s
ete
.
1912] STARR—ANATOMY OF DUNE PLANTS 289
SALIX LONGIFOLIA
Leaf Stem
M Xx M xX
yf A te shigeiapas 188 w (162-212) NS vey 66.5
UE = 5 percent 12 = 6 percent D... 36 “(53) 43 #(55-5)
ioe. 133 =88 165 =88 We: 4
L .i% = 7 Ir = 6 Boe 28 3
a, ee 3 iL 5.3 6.7
Cu... thin 2 R 4 2
isn dah 32
Oar | 48
epee two rows of palisade on X.—Agreeing with the majority in the
eacl side beneath = bapa s, differ- greater area of vessels and greater num-
entiated as a s slid torage region; ber and size of sclerenchyma masses in
ree on both surfaces, slightly sunken. the cortex; exceptional in the larger
-—Upper palisade cells more elongated; lumen of the fibers and fewer growth
sclerenchyma and collenchyma more rings.
abundant in midrib.
Lianas
CELASTRUS SCANDENS
Leaf Stem
. M X M am
— oe 164 » (138-174) N... 37
a. 14 =14 percent 22 =14percent OD... 54 (78) 45.5# (69)
Sa 25 =25 43 =26 Wes: 3-6
4 49 =48 81 =49 rs; 48 4.5
ow a3 iS 18= Ir h.53 Sia os
Cu t thin 4 sees hg ibs
t.7 ae 76
X.—Coarse, often merely acute; veins Chiefly an exception; M greater in
not prominent on under side; other
Variations as usu ual.
area of vessels, heavier fibers and cork.
X follows the majority in having heavier
sclerenchyma around the pith, thicker
walls of the vessels, and smaller lumina
in the fibers.
BOTANICAL GAZETTE
[OCTOBER
PSEDERA QUINQUEFOLIA
x
183 # (164-195)
T.....110 # (99-130) IN 30
UE... 14 =13 per cent 2I =I11 percent D... 78 mw(t20) 61 4 (go)
Pe Sa a a8 = 31 Wo 28 3-4
Sp... . 50° =53 90 =49 Po a 5-9
LE... 13 =12 16 = 9 Ro ae 4-7
OW 2-8 3 d er yee 4 1.2
Cu; 0.7 <5 Ce. 166 188
Se ee iee 62
In both side walls of epidermal cells
plane except in lower surface of M,
cuticle ridged, hairs on the lower surface.
X.—Epidermal cells larger in surface,
smaller in depth; other points as usual
except there is not greater development
of conductive tissues.—Figs. 30 and 31
Exceptional in the smaller area of
cross-sections of vessels in X, less scle-
yma and cork; the cork is loose
and shreds off, so more may have been
lost in X than in M; the other points
agree with the majority.
Fics. 30, 31.—Psedera quinquefolia: sections of leaves; fig. 30, mesophytic form;
fig. 31, dune form.
1912] STARR—ANATOMY OF DUNE PLANTS 291
RHUS TOXICODENDRON
Leaf Stem
M XxX M
T..... 79 # (73-116) 140 & (123-198) «= 18.5
UE... 9 =11percent 12 = gpercent OD... 85 (99) 69 (88)
P..... 29 == 33 45 =32 Wis 2.4
Sp 37 =46 70 =56 | A 2.8
LE. 8 =10 12 =9 pe ee
ay Cee 2.7 Basins 3
Cu...thin 1.4 Gee 184 145
X.—Epidermal cells smaller in depth; Exceptional but in the mass of wood
occasional indications of a double pali- formed.
sade; other points as usual.—Figs. 32
and 33.
Fics. 32-33.—Rhus toxicodendron: sections of leaves; fig. 32, mesophytic form;
fig. 33, dune form.
292 BOTANICAL GAZETTE [OCTOBER
SMILAX HISPIDA
Leaf Stem
(Quadrant used instead of octant)
M xX M
T.....106 @ (96-129) 168 (157-204) N...6bundles; each 6
UE... 11 =11 percent 22 =1 ent with 2 large 2
Mes.. 82 =77 124 =74 vesselsand 18 13
LE... 13 =12 22 =13 smaller
OWs. oss 3:7 D...of large ves-
Cu...thin I sels 105 107
Wie 4
Ee 32 =.6
a ne ee. 4-3
OW.. 18 22
X.—Epidermal cells deeper and larger
in surface extent; outer wall and cuticle
usual monocot
variation, no differentiation into palisade
and sponge.
ae —Two vessels larger, but not so
many small ones; cortex more collen-
pone pith cells with thicker walls,
pith packed with starch grains and
crystals.
VITIS VULPINA
x
153 # (127-164)
M ».4
T.....105 » (100-118) Nose 10
UE... 14 =13 percent 13 = o percent D...105 (142) 102 p (127)
Fis sss 8 45 =2 W..e 4-5
NRRL 81 =53 St 4.8
LE sy 33 14 = o+ L 2.2 7-1
OW : 1.8 R 2-3 2-3
Cu ue , C:.. aa6 307
X.—Upper epidermal cells smaller in X.—Slightly more area in CTFOSS-
depth, larger in surface; hairs on veins sections of vessels; cork thicker; less
on both surfaces (only on upper in M); — sclerenchyma.
other points as usual. In both walls
plane and cuticle somewhat ridged.
1912] STARR—ANATOMY OF DUNE PLANTS 293
Herbs
ASCLEPIAS SYRIACA
Leaf Stem
M P M Xx
T.....225 « (230-296) 272 & (237-304) Bee es
UE... 25 =10 percent 25 = gpercent ts Nae os 46 (66) 64 (87)
P..... 54 =21 77 =28 Wists, 335
Sp....158 =62 Isl =56 eee 2.9 45
LE... 18 = 7 I9 = 7 (See aeaN = 15
wy. 44 2.4 OW fora5- 6.4
Wood cyl - 611
In both side walls of upper epidermal
cells plane, of lower wavy; cuticle —
on lower surface. X.—
| 1atex
and other secretions more abundant.—
Figs. 34 and 3s.
ea of cross-sections of vessels
smaller, larger cylinder of w
outer wall of epidermis and fay odes
collenchyma heavier.
SMILACINA STELLATA
Leaf Stem
M M Xx
T.....174m (155-199) 202 m (182-242) Bundles in field. . 12 12
UE... 28 =16 per cent 30 =I5 per cent N in bundle. .... 15 13
M....119 = 4 =71 sk eae rere 7 eo 3s ew
LE... 27 =16 290 =14 Res en 4.3 4.5
OW... 2.6 2.9 Wc eee vanes 74 6.4
Cw: 0.7 0.7
X.—Epidermal cells smaller in hte
larger in surface; hairs more abundan
esophyll, the general
— side walls of epidermal cells
Pp
X.—aArea of cross-sections of vessels
greater; walls of vessels heavier, but
outer wall thinner.
204 BOTANICAL GAZETTE [OCTOBER
Fics. 34, 35.—Asclepias syriaca: sections of leaves; fig. 34, mesophy tic form;
fig. 35, dune form.
Igt2]
STARR—ANATOMY OF DUNE PLANTS
205
Swamp forms
Sometimes a moving dune passes over a swamp association,
and the members by increased length of stem keep pace with it
for a time; a few of these have been examined and compared with
forms growing in their natural habitat.
PLATANUS OCCIDENTALIS
Leaf Stem
5 X S x
Ti... .152 4 (136-162) 199 & (162-205) N. 66
UE... 23. =1§ percent 25 =12 per cent Ds. 35 #(50) 46 » (63)
P..... 52 =34 63 =32 W. 3.2
Sp. 62 =41 92 =46 ere 3.2
LE... 16 =10 19 =I10 L.. 6.4 7
UW. 4 2.8 Kio a 2
Ca 68 6.9
eds «KOO 116
Collen 56 109
The dune form has thicker leaves than
the swamp form, but the palisade and
outer wall of the epidermis are excep-
tional.
The dune form shows an increase in
number and size of the vessels, but there
is no increase in woody tissue aE
by the fi seems to be
outside the stele and the cork have in-
creased.
INCANA
Swamp form, vessels is! than the
others but fewer in number. Dune
form, larger area of vessels. Thickness
of walls about the same.
CEPHALANTHUS OCCIDENTALIS
ALNUS
Stem
5S x
* ben Chae peek ee 68 61
ee 29 34
eee 2.5 2.6
ON apres eres oe. 3-5 3-4
ae 7 8.8
S
a 175 (143-168) 1636 (147-189)
= 16 9 t 17 =10 per cent
++. $4 =3r 48 =29
Sp.. or =52 84 =52
LE. 14 = 8 14 = 9
ve 3 3-7
ee 2
A second layer of palisade is partly
organized i swamp form and com-
caly in the dune form. The first
alisade is relatively shorter in the dune
form, but the second is so much more
compact than in the swamp form that it
must more than make up the amount
of tissue. In both forms stomata are
found on the lower surface only and the
side walls of the epidermal cells are
waxy
206 BOTANICAL GAZETTE [OCTOBER
SALIX GLAUCOPHYLLA
Lea Stem
M x Ss
T....,185 « (180-208) 231 mw (219-240) Ne 8) 64
UE... 20 =10 per cent I9 = g per cent Diss ag 47
Pe. 92 =50 120 =52 Wo. 5253 2:4
Sp.... §7 =31 69 =30 E, 9.2 4.8
LE... 16 = 8 19 = 9 L. 5 3.2
OW. 4.3 4.8 2-4
Cu. 1.6 1.6
Cork.. 56 80
Collen 4-6 layers 7 layers
Little variation, but the palisade is In the dune form more vessels and
slightly deeper in the dune form; the larger; the fibers heavier and the lumina
vessels of the midrib are larger though smaller, giving more wood; growth rings
about as numerous, their walls are heavier about the same; more cork, collenchyma,
as is also the outer epidermal wall, and and sclerenchyma.
there is more collenchyma.
CORNUS STOLONIFERA
A plant growing on the edge of a river was partly submerged by a dune. The
stem was examined to find the difference between the submerged and the aerial parts.
Submerged
Cortex and phloem. ............. 400 380M
WIG PORNO a ok Gs 836 950
ig ER eee peg eo Ee er ee rome 1976 1482
3317 2812
The upper exposed part is not as large as the submerged part, but the wood
cylinder is larger.
Submerged Aerial
2 4
bit Sia a AANA Ns he 6 4
BO erie cee ses do epiaeen 23 38
Weel ces 2.3 Oe:
5 es Oe Oe ee os gt 5.6
ee ee I0.4 6
In a given area in the cylinder there are fewer vessels, larger in diameter but less
in area, which must be more than compensated for by the size of the whole cylinder.
The walls of the vessels and fibers are heavier and the lumina of the fibers smaller,
giving more wood.
SALIX LONGIFOLIA
Situation the same, but the parts examined were not parts of the same stem, but
were of the same size
Perea cies cs reese eciies
De pire eeea i ee, 41 43
i PEERS ON er ger 3.3 2.4
gee 3.2
| re ee ee rere ee 6.8
7: :
In aerial stem more and larger vessels, walls slightly thicker, lumina fd is
smaller, giving more wood. civtic
swamp forms on the whole show the same variations as the mesop: yu
forms.
1912] STARR—ANATOMY OF DUNE PLANTS 207
Table (I) on p. 298 gives a comparison of mesophytic and dune
forms of the same species with respect to eleven characters of
’ the leaf.
A summary of leaf characters is as follows:
a 12X (3 same)
Surface of upper epidermal cells greater.............. 9 X- 5 M (2 same)
Depth of upper epidermal cells greater............... 5 X-12 M (4 same)
Side walls of upper epidermal cells wavy.............. 6 X-11 M
Side walls of lower epidermal cells wavy.............- 8 X-16 M
Outer wall of epidermis heavier...................... 18 X (2 same)
Ravan SM ee des i 10X- 6M
Palisade more completely organized.................- 17X (x same)
Better development of conductive elements........... 15 X— 2M (x same)
Puma viet echentrictymas 0 A Foes 14 X- 1M (1 same)
PIOWU ET COORD VINR os res vw ce news 17X
All leaves, with the exception of those of Populus balsamifera,
were thicker in the dune form than in the mesophytic. The poplar
was growing alone at the side of a road, so the exposure was greater
than in the woods where most of the mesophytic specimens were
collected. The bud scales also were thicker, and in most cases the
outer wall, or the cork if it had developed, was thicker.
The greater extent of surface in the upper epidermal cells in the
majority of the dune forms is striking. GREVILLIUS speaks of
epidermal cells in the alvar plants being smaller than in the normal,
but he may have used the lower surface only, as he mentions the
subject in connection with stomata, and that may differ from the
upper surface. Cuticular transpiration is reported as taking place
from the side walls of the epidermal cells more abundantly than from
the lumen of the cell. If this is true, then increase in the surface
extent of the cell would decrease cuticular transpiration. The
apparent thickness of the epidermis of dune forms is due to the
heavy wall and cuticle and not to the depth of the cells. Waviness
of the side walls seems to be related to shade, as it occurs more
frequently in mesophytic leaves, and in mesophytic leaves on the
under side. Ridging of the cuticle accompanies great thickness.
Deep, compact palisade, well developed conductive elements,
heavy sclerenchyma, and the presence of hairs are characters noted
[OCTOBER
BOTANICAL GAZETTE
298
Sele) el eee lee x | x ORR ew | we Rh ek eas eens PULAYIUDTIOS IOLAvAyT
Gta) ma) ee Te) we | ed e | fe le] x See evurAyouaraos IOIAGOTT
XU | X x UW x % | XU | Ub x x x x x x x x x Bee ee Ee S$}UIUISTS
sATPNpUuoI jo jJusUIdofaAap sJaqj0g
Him be Be ME |e | ee | st w]e) e |e |e) & | © | & | & | pazrtesio AJa}0;dUI09 or0ur opesieg
xu | um | xu | x xu | wm | x x £1 % ce ac ce 6 cya iel 2a acim eae peSpu spring
eo) e | eee ee ee Pe |) we | eel ee fe el we le le ee JatAvey (apd But
“pnpur) stutrepida jo syyea soyNC
vue | ue | wm | xu | vue uw} um \|xums| o | um ue | ue | wm | Ue hia Cepeciess ‘adwcl |: SESS os sei) AAR
S][99 TeulIaprda samo] Jo sTfem apis
o}|m! o | xm | xm um} o\|xum|o | o | Ub | Rib | Me | Me | eH | OO | MMR Tt etter eens ee AatM
S][99 Teuaspida z9ddn jo sytem aprg
wale) ml we | me) ello) | a le) ek | all | ell Pe | OE SS a 8 4 6 oa ee 197013
APALeper sp[eo Teurrapida yo yydaqy
x | ut x x x x x x UL wm | vu Ub Wh x x MU | Pits t esses cece w ese ces I0}va13
Ajaqnjosqe S199 yeurrapida Jo aoeying
|X ixm | o | 1 ole] w lem) we | we | om ole |} 25 @ On 2 ete juepunge aiour siezy
w wn oH
= ¢ z BlBIS E e Fi 2 Bg ro g 219 ze fe g z
E BF) Ee 6 f B/ee/EE|s | & :
41s “P16 | BE
S 8 a
GTAVANOD SACI ANAC GNV OILAHAOSAN LO SHALOVAVHO AVva’]
I aTaVL
1912] STARR—ANATOMY OF DUNE PLANTS 299
in true dune plants and generally admitted to be xerophytic.
Stomata appear only on the under sides of leaves of both forms
except in the cases noted, where they appear on both sides; there
is no variation except in the one tree Ostrya which sometimes has
stomata on the upper surface also. Occasionally specimens from
mesophytic situations in the dunes show interesting variations. In
these places a great deal of humus has collected above the sand,
changing the water content and other soil relations, and xerophytic
pioneers have made enough shade and protection for mesophytic
forms to come in, so woods have developed. The exposure must
be less here and the water relations better than on dunes with
Sscantier vegetation, yet leaves of Fraxinus, Cornus, and Ostrya
. collected in these woods were thicker than some of the dune forms.
The internal structure of Fraxinus differed from the dune form,
the palisade consisting of a single layer of cells, not compactly
arranged.
Another interesting variation comes out in the comparison of
leaves of different seasons. Those collected in 1911 are frequently
thicker than those collected in 1909 in the same habitat, so that
the mesophytic form of 1911 is sometimes thicker than the xero-
phytic form of 1909, but the xerophytic form of 1911 is correspond-
ingly increased. The season was an unusual one, showing
temperatures of 39°, 46°, and 66°, for March, April, and May, in
which time the leaves became fully mature, the normal being
34-4", 45.9°, and 56. 5°. In 1909 the temperature was very near
the normal. The normal percentages of possible sunshine are 52,
60, and 64, while 1911 had 63, 54, and 79, so March and May were
considerably above the average, though April went below. Precipi-
tation was near the normal except in March, when it was only a
little more than half. Winds were not unusually high. The
variation in thickness must have been due, at least in part, to
the unusually high temperature in the three months, sunshine
above the average in March and May, and small precipitation in
March.
The accompanying table (II) gives a comparison of mesophytic
and dune forms as to nine characters of the stem.
BOTANICAL GAZETTE [OCTOBER
ma |e Reese a
8
sm | #SRRES REE
S
mr} eReeeee &§
xyms | Sexe
wpymg | SRS Fee BR
mae Seegee Beez
snyy | SERRRR BARB
vaaIg ee Rees RRR ’
erapsg | sSSeee BS
URTULSIIA 8
‘snunig RERR ER sea
10zJ9P
ge RRRRRR RRA
od RERRER RRA
eAsO | SERERR HRB
uoIpuspolm7yT | RSERRRR BRS
suyanf | RRERRER FRE
TABLE IT
sIpururyy | ek Sexes
8
uma | SSX RR FE FRA
ce
STEM CHARACTERS OF MESOPHYTIC AND DUNE FORMS COMPARED
suidapsy | FERRER 8
wmoy | SkeexeeB® FEE
Seite: hea =
Gatien mere. eel Po .
ST) a eS
kn eer Ee.
a oe tee.
a a5;
g Beige og:
oat pan: .
© :98s88e:8:
§ i985 000:8-
3S -OnH wn. - a>
G+ Pes BES !
gs 28e5 :2y
Base Ess (a
ee “Old
gasceee ges
ad
boise b3 8x
PeRBERA AO
1912] STARR—ANATOMY OF DUNE PLANTS 301
A summary of stem characters is as follows:
ueeeere More DOMOTNUS ; s,s ca cad e 14 X- 7 M (1 same)
WEE se ee ee o X-11 M (2 same)
eens Oh 1 i Vide ed eee 17X- 5M
enh Ol wenbele helivied oo a oi 16 X- 4M (2 same)
TN OE DOANE Weitel o iky eks he 14 X— 6 M (1 same)
ween 8 Gers enalier.. os es 16 X— 2M (2 same)
me OW fine ee 10 X—- 6 M (3 same)
More sclerenchyma and collenchyma................. 15 X— 6 M (x same)
free Coeeee oe A o X- 8 M (1 same)
There is a tendency for the vessels to be larger in the mesophytic
forms, but more numerous in the xerophytic, the area being greater
in the xerophytic. A greater number of xerophytic forms have
heavier walls of vessels and fibers and smaller lumen in the fibers,
making a more woody cylinder. A majority of xerophytic forms
have more growth rings to the given diameter than the mesophytic
forms, showing slower growth under the more adverse conditions.
A majority of xerophytic forms show an increase in mechanical
tissue as well as in the wood and an increase in cork formation,
though this is not so marked as one might expect. The internodes
in the stem, in every case measured, were shorter in the xerophytic
form.
The lianas seem more apt than the trees to show exceptions to
the general stem situation. Their vessels are always extraordinarily
large, but why they should often be larger and more numerous in
mesophytic forms, when those of trees are not, is impossible to guess.
Discussion of theories
That the characters cited are due to the conditions under which
the plants live, or have lived in the past, is undoubted, but what
are the immediate causes remains to be proved by experiment. The
Purpose of this investigation has been to get at a few facts, but it
may be of some interest to review a few of the theories: :
Mrs. CLemENts (4) considered light the principal factor in
the development of deep palisade. HABeRLANDT (16) said that
light does not influence the structure of this tissue but only its
disposition, and that the reason palisade is developed is because
302 BOTANICAL GAZETTE [OCTOBER -
the products of assimilation ought to be carried away from the
assimilatory cells by the shortest possible road, and the form of
cells best fitted for this rapid transportation is the elongated form.
WAGNER (29) reported that alpine plants exposed to decreased
transpiration did not show a reduction in palisade, and concluded
that not transpiration but assimilation was more effective in produ-
cing that tissue. Prick (25) thought the elongated form of the
palisade is ancestral, but that for a strong development light is nec-
essary; Durour (9) agreed with him in this respect. SraHt (26)
related palisade development to light. EBrrpt (10). thought that
increase in palisade development is caused by assimilation and
transpiration working together, and that light in itself is never
the cause that calls forth palisade parenchyma. VESQUE and
Viet (27) concluded from their experiments that light and dry air
(accelerating transpiration) result in a greater development of
' palisade. BONNIER (2) adds temperature to these two factors.
KEARNEY (22) considers excessive transpiration accountable for
both increased palisade and succulency. HErNRICHER (20) related
equilateral structure to the vertical position of leaves and thought
it due to sunny and dry situations, dryness being secondary to
strong illumination, as some plants growing in damp situations
have equilateral leaves.
As to conductive and mechanical elements, it has long been
known that they are reduced in aquatic plants, in the water leaf of
Proserpinaca being scarcely differentiated at all. If the supply
of water is the limiting factor, one would expect an increase in
these tissues the more xerophytic the conditions; but of course
water is not the only factor, and with the plant out of water, its
roots in the soil, its leaves in the air, the larger the plant, and
consequently the farther apart the roots and leaves, the more
complicated become the factors. Gute (14) found in the xerophytic
family Restiaceae a mechanical ring of strongly thickened cells,
which VorKENs (28) explained as related to poor water supply:
HABERLANDT (17) thought mechanical influences, if they do not
pass beyond a certain limit, act on stereome as a stimulus for further
building it up. Kout (23) found that in some plants grown in
damp air the sclerenchyma ring was entirely lost, xylem elements
1912] STARR—ANATOMY OF DUNE PLANTS 303
less numerously developed, and bast bundles weak or gone, due, he
said, to differences in activity of transpiration. Jost (21) found
that in Phaseolus a great mass of vessels was formed, even if
transpiration was reduced to the minimum, and says “transpira-
tion can indeed influence the quality and quantity of the vessels;
but is not the cause of their formation. If it were so, the stems of
our trees would grow in thickness as long as they transpire, at
least the whole summer through, which they do not do.” HaBER-
LANDT (18) relates the number and size of the ducts to the transpir-
ing leaf surface. Harric (19) agrees with HABERLANDT and adds
“in the damp air of a dense forest the inner spaces are much nar-
rower than in an open stand.’”’ PFEFFER (24) considers that within
certain limits the development of the conducting system is favored
when an increased demand is made upon it. VoLKENs (28), in
studies of desert plants, found a small development of water-
conducting elements. CANNoN (5) irrigated desert plants and
compared their ducts with those of non-irrigated plants and found
better development in the latter. The two results may not be
inconsistent. VorxKENs’ plants may have reduced leaf surface or
developed succulency, thus reducing transpiration, and so in a
Way correspond with CANNon’s irrigated plants.
Conclusions
Conditions in the dunes are severe for plant life, including direct
illumination and reflection, extremes of temperature, strong
winds, sand-blast, and sandy soil, the result of all these factors
eing increased evaporation. The presence of considerable water
above the water-table makes conditions less severe than they
Otherwise would be. The response to these conditions by true
dune plants is seen in the predominance of low vegetation, long
Toots, woody stems, thick leaves (which may be reduced, equilat-
eral, evergreen, or folded), succulency, hairs, thickened epidermis
and cuticle, deep palisade, sunken stomata, and well developed
mechanical and conductive tissues in all parts.
Plants generally growing in mesophytic situations, when found
also on the dunes, show the following modifications: of the leaf,
increased thickness, decrease in depth and increase in surface-
304 BOTANICAL GAZETTE [OCTOBER
extent of epidermal cells, increase in thickness of the outer wall of
the epidermis and of the cuticle accompanied by ridging, increase
in palisade, in hairs, in conductive and mechanical tissues; of the
stem, decrease in the length of internodes, increase in the number
of vessels and in the area of their cross-sections, giving greater
conductive space, increase in thickness of the walls of vessels and
of the fibers accompanied by decrease in lumen of fibers, giving
more wood, increase in the number of growth rings in stem of a
given size, showing slowness of growth, increase in mechanical
tissues outside the wood, and increase in cork.
Mr. Hotyoxe CoLlLecrE
South HapLeEy, Mass.
LITERATURE CITED
1. Bonnter, G., Cultures experimentales dans les Alpes et les Pyrénées.
Rev. Gén. Bot. 22513-546. pls. 20-23. figs. 192-203. 1890
, Recherches experimentales sur |’adaptation des oinures au climat
alpin. Ann. Sci. Nat. Bot. VII. 20: 217-360. pls. 5-16. figs. 20-47. 1895.
3- Buscationt, T., and Porxacct, G., L’applicazione delle pellicole di collodio
allo studio di ‘aleiat a fisiologici nelle piante. Atti Ist. Bot.
Pavia. N.S. 7:12. pl. 1. 190
4. CLEMENTs, 4 S., Relation iy leaf structure to physical factors. Trans.
Amer. Micr. Soc: 26:19-102. pls. 1-9. 1904.
5. CANNON, W. A., Water-conducting systems of some desert plants. Bor.
Gaz. 39: 307-408. figs. I-10. 1905.
6. CHERMEZON, H., Recherches anatomiques sur les plantes littorales. Ann.
Sci. Nat. Bot. IX. 12:117-313. figs. 52. IgI0.
7. CHRYSLER, M. A., Anatomical notes on certain strand plants. Bot. GAZ.
— 372461-463. 1904.
8. Cow es, H. C., The ecological relations of the vegetation of the sand dunes
of Lake Michigan. Bor. Gaz. 27:95-117, 167-202, 281-308, 361-391:
figs. 1-26. 1899.
9. Durour, L., Influence de la lumiére sur la forme et la structure des feuilles.
Ann. Sci. Nat. Bot. VIL. 5:311-411. pls. g-r4. 1887.
10. EBERDT, O., Ueber das Palissadenparenchym. Ber. Deutsch. Bot.
Gesells. Siiho-i. 1888.
11. Firtinc, H., Die Wassersorgung und die pales Druckverhiltnisse
der Wikhtedeiiaiunn: Zeit. Bot. 3: 209-275.
12. Futier, G. D., Evaporation and plant acaba ioe Gaz. §2: 193-208.
figs. 1-6. 1912.
ee
1912] STARR—ANATOMY OF DUNE PLANTS 305
13. FuLLerR, G. D., Soil moisture in the cottonwood dune association of Lake
BE biean. Bor. GAZ. 53:512-514. 1912.
Gite, E., Beitrige zur vergleichenden Anatomie der xerophilen Familie
der Peitiscces. Bot. Jahrb. 13: 541-606. pls. 7-9. 1891.
15. GREvILLIus, A. Y., Morphologisch-anatomische Studien iiber die xerophile
Bidasroecmenvesstation der Insel Oland. Bot. Jahrb. 23: 24-108.
pls. 1-3. 1897.
16. HaBertannt, G., Vergleichende Anatomie des assimilatorischen Gewebe-
b
Lal
>
systems der Paliisext: Jahrb. Wiss. Bot. 13: 74-188. pls. 3-8. 1881.
17. , Physiologische Pflanzenanatomie. Leipzig. Ed. by W. Engel-
mann, 2d edition, p. 171. 1896
seers, J Did. DH. 270.
19. Hartic, R., Ueber Dickenwachsthum und Jahresringbildung. Bot. Zeit.
50:193-195. 1892.
20. HEINRICHER, E., Ueber isolateralen Blattbau mit besonderer Beriick-
sichtigung der europiischen, speciell der deutschen Flora. Jahrb. Wiss.
Bot. 15: 502-567. pls. 27-31. 1884.
21. Jost, L., Ueber Dickenwachsthum und Taiecichaghidane. Bot. Zeit
49: 485-405, 501- Pe ae 539, 541-547, 557-593, 573-579, 589-595, 605-
611, 625-630. pls. 6, 7. 1891
22. KEApney, pee se i plant covecix of Ocracoke Island. Contrib. U.S.
Nat. Herb. 5: 261-319. pls. 65. figs. 33-50. 1900
23. Kout, F. G., Die Transpiration der Pflanzen ca ihre Einwirkung auf die
Ausbildung pflanzlicher Gewebe. Braunschweig, H. Bruhn. 1886.
24. PFEFFER, W., Physiology of plants. Transl. and ed. by A. J. Ewart.
Oxford, Clarendon Press. 2d edition. 1800
25. Pick, H., Ueber den Einfluss des Lichtes “a die Gestalt und Orientirung
der Zellen des Assimilationsgewebes. Bot. Centralbl. 11: 400-406, 438-
445- pl. 5: 1882.
26. Sraut, E., Ueber den Einfluss der Lichtintensita&t auf sche a und Anord-
nung des Aneinsiliecacdiieinaibe: Bot. Zeit. 38:868- 1880.
27. VESQUE, J., and Viet, Cu., De influence du neo sur it structure
anatomique des vegetaux. Ann. Sci. Nat. Bot. VI. 12:167-176. 1
28. VoLKens, G., Die Flora der agyptisch-arabischen Wiiste auf Grecian
anatomisch-physiologischer Forschungen. pp. 156. pis. 18. Berlin. 1887.
Waener, A., Zur Kenntnis des Blattbaues der Alpenpflanzen und dessén
biclogischer Bedeutung. Sitzber. Wiener Akad. 101:487-548. pls. 12.
1892.
S
Q
PARNASSIA AND SOME ALLIED GENERA
LULA PACE
(WITH PLATES XIV—XVII)
The systematists have had some trouble in classifying Parnassia.
In an old Westphalian Flora by Karscu (15) it is placed in the
family Droseraceae. HALLIER (12), in discussing the Saxifragaceae,
says Parnassia is much more closely related to the Droseraceae than
to the Saxifragaceae; while EICHINGER (6) concludes that it should
be placed with the Saxifragaceae as ENGLER (8) has it. WETTSTEIN
(26) also places it there and takes Droseraceae out of the Sarra-
ceniales and puts it with Parietales. The possibility of finding
some characteristics that would help settle this question led to the
present study. CHopat (3) has used Parnassia to illustrate certain
stages in the development of the embryo sac and embryo of
angiosperms.
The work was undertaken at the suggestion of the late Professor
STRASBURGER, and his continued advice was of the greatest service.
Parnassia palustris
MATERIAL.—The material which had been collected in Switzer-
land, and in the neighborhood of Bonn, Germany, was kindly placed
at my disposal by Professor SrRASBURGER. It had been killed in
an alcohol acetic mixture (three parts of alcohol to one part of
glacial acetic acid). The usual methods were followed in preparing
the material for cutting. The younger stages were cut 5-6 » thick
and the older 8-10 ». The triple stain, safranin-gentian violet-
orange G, was most satisfactory, but iron-alum pemetoxyia alone
and with Congo red was also used.
The parts studied showed very few irregularities, or so-called
abnormalities. Out of several hundred ovaries sectioned, the
majority had five placentae, a few had four, two had three, and
one had only two; in the last the two placentae were not quite
normal in appearance. One ovary had a very irregular structure;
it was as if the carpels had not grown together, and more or less
Botanical Gazette, vol. 54] [306
1912] PACE—PARNASSIA 307
perfect anthers, containing apparently normal pollen, were found
on these (fig. 70). One anther had developed on a staminodium;
two anthers were normal in appearance. CHAMBERLAIN (2) has
reported certain somewhat similar irregularities in anther develop-
ment in Salix.
MEGasporRES.—A complete series in the development of the
ovule from the first protuberance was studied. The earliest stages
show no differentiation of sporogenous tissue. The first difference
to be noted is in ovules that are somewhat advanced; and these
show only a difference in the size of the cells, there being no definite
arrangement of these and no difference in staining reaction. Cer-
tain characteristic groups of these larger cells are shown in figs. 1,
2, and 3; the first two are from the same section. Often there are
only two large cells, as may be seen in fig. 1, but in this case a third
cell is below these two. Fig. 2 has four large cells that evidently
were produced from one cell by two successive divisions, thus giving
a rather striking resemblance to four megaspores; the wall between
the two upper cells is very faint. At this stage, if the section is not
perpendicular to the wall, one gets the impression of two nuclei
without a separating wall, as CHopat (3) has shown in his fig. 660;
but I found no case in which the wall was really lacking. Fig. 3 is
an ovule with one of the large cells in mitosis, showing the 20
chromosomes of the diploid generation. The ovule is somewhat
larger before the difference in staining reaction appears, and the
difference in the size of the cells is also more striking (fig. 4).
The inner integument begins to develop at this time. Fig. 5 has
both integuments and the sporogenous cell is in synapsis. Synapsis
was not found in younger ovules, but apparently it continues for
some time, as it was often found in much older ovules, judging by
the development of the integument. CHopat’s fig. 660, c (3), is
similar to fig. 5, except that he shows the nucleus without other con-
tents than the nucleolus. Only a few instances were found in which
more than one cell showed both by size and staining reaction the
sporogenous characteristics. Fig. 6 gives two sporogenous cells,
the cell with the nucleus in synapsis being much the larger. In fig.
7 the cells are approximately the same size, but the section was cut
so that one cell was unfortunately directly over the other. Here
308 BOTANICAL GAZETTE [OCTOBER
the cell in synapsis is somewhat shorter and broader than the other.
The walls of one cell are dotted in, but the walls of the other and
both nuclei are drawn.
The mother cell divides in the usual manner (figs. 4, 8, 9). A
full series was studied, but only a few drawings will be shown. In
fig. 5 the synapsis stage is shown and in fig. 8 the spirem. The
chromosomes are quite short and thick in fig. 9, and the haploid
“number (ro) can be counted. The daughter cells sometimes differ
slightly in size, but as a rule the difference is not marked (fig. 10).
In fig. 11 the lower daughter cell has the spindle already formed for
the second division, while the upper daughter cell has only formed
the chromosomes, the nuclear membrane being still complete and
very distinct. But in fig. 12 both daughter nuclei are in the early
telophase of this division. In the upper cell one chromosome did
not reach the pole and was left out of the megaspore nucleus. —
This condition was seen only a few times; and, as the upper mega-
spore always disintegrates in the material studied, it does not seem
to be of any importance in the life-history of this plant. One
example of the same condition was found in the first division. Here
it might affect the life-history; for very often the second megaspore
develops. If the nuclei continued to divide as usual, this might give
an egg with one less than the usual number of chromosomes, in this
case 9 instead of ro.
Figs. 13-15 show the different positions of the megaspores, 4
straight row in fig. 13, the two lower in a row and the two upper
side by side in fig. 14, and approaching the tetrad form in fig. 15-
CHopAT (3) gives in his fig. 661 a straight row of four megaspores
and in fig. 662 a row of three cells; in both cases the lower mega-
spore has enlarged to produce the embryo sac.
Emprvo sac.—While in angiosperms it is probably true that the
lowest of the four megaspores usually produces the embryo sac, the
others disintegrating, cases showing that any of the four may
function have been reported, and in some instances all four show
sac tendencies. CouLTER and CHAMBERLAIN (4, p. 84) give 4
summary of the literature on this subject. In Parnassia apparently
the second or the third as frequently develops as the fourth (figs.
16-29), but no case was found in which the first developed. These
1912] PACE—PARNASSIA 309
figures show that often two of the megaspores begin to develop,
apparently either two of the lower three, second and fourth (figs.
16-18), second and third (fig. 17), third and fourth (figs. 22 and 24).
In fig. 25 one of the two upper adjacent megaspores and the fourth
one began to develop, but the upper one is in the best condition,
the fourth one being less dark than the other two, but darker than the
upper one. The epidermis is quite pale over this spore. Fig. 23
has the appearance of five megaspores, but one nucleus is quite
small with apparently only one chromosome, and is probably the
result of an abnormal division like that shown in fig. 12.
The epidermal layer of the nucellus begins very early to dis-
integrate. These cells nowhere had the usual appearance of
disintegrating cells. As is well known, cells disintegrating under
apparently similar conditions stain deeply and have a more or less
crushed or squeezed appearance. But here they seem to grow paler,
as if the cytoplasm within them were diminishing, and finally all
contents disappear. Later the walls also are more or less com-
pletely absorbed. An attempt to show this is made in figs. 24, 26,
27- In fig. 24 the whole epidermal layer is pale almost to the base
of the fourth megaspore; in figs. 26 and 27 the cells are disappearing
from the upper part of the nucellus, leaving the megaspores lying
next to the inner integument. The disintegration in this region
continues until only the lower end of the sac is inclosed by nucellar
tissue, the greater part of it being in contact with the integument
and having no cells between it and the micropyle (figs. 30, 31,
33-36). CHopat’s (3) figs. 661-666 show this disintegration of
nucellar tissue. He says:
Chez beaucoup de Gamopétales et ches quelques Dialypétales la mégaspore
qui s'est développée dans un trés petit nucelle dissont le sommet - celui-ci et
fait saillie an dehors dans le micropyle.
The disorganization of this layer of cells may furnish food to the
upper megaspores and thus give them a better chance to develop
than they would otherwise have. On the other hand, it is altogether
Possible that this disintegration is due to the unusual activity of
these megaspores.
Fig. 27 shows a two-nucleate sac that developed from the second
megaspore; the third megaspore is quite large and as yet shows no
310 BOTANICAL GAZETTE [OCTOBER
signs of disintegration. The fourth megaspore is fast disorganizing,
being a darkly stained almost structureless mass. The first mega-
spore and the nucellar layer over the upper part of the sac show only
traces of their former existence. An embryo sac developing from
the fourth megaspore is shown in fig. 28. The nucleus is in mitosis
for the first division, and the 10 chromosomes can be counted. The
three upper megaspores are completely disorganized, and the
nucellar cells near the micropyle are paler and with very little con-
tents. The vacuole appears early in the two-nucleate sac (fig. 29).
It is not common to find the second and the third megaspores per-
sisting so long as they have here. The two upper nucellar cells have
very little cytoplasm in them and stain much lighter than the others.
In fig. 30 an entire ovule at a little later stage is shown with less
magnification. The nucellar layer has disappeared completely from
around the upper part of the sac, leaving it in contact with the inner
integument and an open micropyle all the way to the sac. The only
part of the nucellus remaining is that below the lower-nucleus of the
two-nucleate sac. It is interesting to note that SHREVE (20) has
shown a similar figure for Sarracenia, all the nucellar tissue except
that at the base having been destroyed. The loose, spongy tissue is
already appearing in the chalazal end of the ovules. This becomes
very conspicuous in older stages.
Figs. 31 and 32 show the second mitosis in the embryo sac. In
one nucleus of each sac it is possible to count the 10 chromosomes.
In the first the chromosomes have been formed in both nuclei, in the
second only in the lower one; the upper one has the spirem very
thick and short and probably shows the early stages of segmentation.
In both ovules the nucellar layer has disappeared from the upper
half of the sac. The spindles for the second division are at right
angles to each other (fig. 33). This sac developed from the second
megaspore, and in this case the third one has also begun to develop.
Fig. 34 shows a four-nucleate sac with the chromosomes more OF
less completely segmented for the third division. The nucellar
layer has disappeared from the upper two-thirds of the sac. The
inner layer of cells of the integument is shown on one side of the sae
in fig. 35. The sac nuclei are in the late anaphase of the third
division. The upper spindle is almost perpendicular to the pape?
1912] PACE—PARNASSIA 215
and so it is not easy to show it correctly. Each of these spindles
shows the thickening of the spindle fibers in the center, characteristic
of early wall formation, but further development of the walls does
not take place, as is shown in fig. 36. The nucellar layer is repre-
sented by a more or less distinct line of stuff which can be traced to
the perfect cells below the sac. The darker thicker mass near the
micropyle is probably the remains of the megaspores.
The eight nuclei arrange themselves in the usual fashion (fig.
37). In this figure the egg lies just back of the synergids and only
the lower part of it is shown in the drawing; and the polars are
almost in contact. Here the large nucleoli characteristic of these
nuclei are well shown, the nuclei having very little other stainable
material in them. In this case practically all of this material is
shown in the drawing, which was made not with a single focus, but
by focusing in all parts of the nuclei. At any given focus one’s first
impression of the nucleus is an empty circle except for the very large
nucleolus. The inner layer of cells of the integument is drawn on
only one side of the sac. This layer has the appearance of the
so-called tapetum or jacket layer formed in many of the Sympetalae,
as well as in other forms, and is quite different in appearance from
the adjacent cells. CHAMBERLAIN (1) has shown it in Aster novae-
angliae. EICHINGER (6) says:
Bei unserer Parnassia kann man fiiglich von einem Tapetum nicht
sprechen, die innersten Zellen des Integuments unterscheiden sich nicht all-
zusehr von den andern.
But in my material the difference in shape and staining was striking.
Small vacuoles are already present in the synergids. One
Synergid shows the beginning of the indentation, Leiste of
STRASBURGER (21), which in later stages gives a caplike appearance
to the upper part of the synergid. It seems to be related to the
cytoplasm of the sac, that is, it is always just where the cytoplasm
of the sac reaches its highest point of contact with the synergid.
It seems probable that, as the filiform apparatus develops (being of
cellulose, it is somewhat stiff) and the synergids elongate, this upper
Stiffer part does not change shape so much as the lower part. A
filiform apparatus is common in angiosperms, but it is not always so
Strikingly developed as here. In Die Angiospermen und die Gymno-
312 BOTANICAL GAZETTE [OCTOBER
_spermen (22), STRASBURGER shows (pl. 2, fig. 19) a filiform appa-
ratus, but no notch in Polygonum divaricatum. COULTER and
CHAMBERLAIN (4, p. 94) say that ‘“‘such beak-like extensions of the
sac and synergids are usually associated with narrow and long
micropyles.”” But in Parnassia the micropyle is usually wide open
and even all nucellar cells have nome ooh — this region.
A similar filiform apparatus and by STRASBURGER
(21) in Santalum. This j is shown quite clearly in spite of the very
imperfect technique of that time. In Santaluwm the notch seems to
be definitely related to the embryo sac wall, the upper part of the
synergids protruding beyond the wall, and this indentation being
just against the upper end of this broken wall. NAWASCHIN (16)
shows in his fig. 9 a very deep notch in the synergids of Helianthus
annuus. The synergids are pointed, but do not show the lines of the
filiform apparatus in the upper part, although just below the notch
the lines are quite distinct. This part of the figure is not described,
and it may be that the upper part has the usual lines of the filiform
apparatus, but they failed to appear in the plate. Here the notch
seems definitely related to the cytoplasm of the sac, very much as
it is in Parnassia. JuEL (14) shows the usual embryo sac in
Saxifraga granulata, but does not describe a filiform apparatus.
This stage he shows in a microphotograph which is quite indistinct
in this region. Fig. 38 is slightly older; the filiform apparatus is
beginning to develop in the synergids. The nucleus is above the
vacuole in one and below it in the other synergid. Fig. 39 has an
unusual development of the vacuoles in the synergids; here the
polars are in contact. In fig. 40 the vacuoles are below the nuclei
in both synergids, and the polars have fused, forming the primary
endosperm nucleus. The filiform apparatus and notch are quite
distinct by this time. Another view of a sac of about the same stage
is shown in fig. 41. In this ovary many sacs were still in the four-
nucleate condition. :
The upper part of a mature sac is shown in fig. 42. The polars
have already fused. In Parnassia they apparently always fuse
immediately, as they are fused in all the mature sacs examined. The
caplike filiform apparatus is always very conspicuous at this stage,
and stains red with Congo red, which shows it to be cellulose. The
1912] PACE—PARNASSIA 313
inner row of cells of the integument next to this part of the sac is
disintegrating, the disorganization being more or less complete as
far down as the last cell drawn, which seems to be still active, as
both nucleus and cytoplasm have the usual staining reaction and
structure of active cells. Fig. 43 is the other view of a similar sac,
being cut at right angles to that of fig. 42; the other synergid is
directly under the one drawn. Here the egg apparatus is farther
up in the micropyle, and a few of the cells of the integument over
the filiform cap have entirely disappeared. CHopAT (3) shows an
embryo sac before and after fusion of the polars in his figs. 664 and
665, but does not show the filiform apparatus of the synergids.
His fig. 677 suggests the possibility of its presence, but does not show
it clearly. The pollen tube is just below it.
In many ovules the egg apparatus is entirely in the micropyle,
a few of the cells of the integument being disorganized in most
instances (fig. 44). The whole egg apparatus has the appearance of
being squeezed into a space too small for it. The polars have fused.
In fig. 45 the synergids lie one above the other in the micropyle, the
egg being just at its entrance. These synergids show the notch and
the filiform appearance quite distinctly. If the synergids are not
entirely separated, they may have somewhat the appearance of
pollen tubes; but it is always easy to distinguish them from the
latter by the difference in staining reaction, and by the fact that the
real tube structure is.lacking. A diagram with less magnification
(fig. 46) shows the whole upper portion of the ovule. Fig. 47 shows
one synergid nucleus just at the entrance of the micropyle, some of
the cytoplasm of this synergid being entirely outside of the ovule.
In fig. 48 the entire egg apparatus is just at the entrance to the
micropyle, with the polars in contact in the upper part of the sac.
A few ovules were seen in which the whole of the egg apparatus was
entirely outside of the micropyle. These figures with the synergids
in the micropyle are very similar to the structures shown by CHODAT
(3) in his figs. 675-676, which he calls pollen tubes.
PoLLEN.—The anthers present the usual four-lobed appearance,
with four sporogenous regions. A group of mother cells in more or
less perfect synapsis is shown in fig. 49. After synapsis there is a
thick spirem which segments into 10 chromosomes (fig. 50). The
314 BOTANICAL GAZETTE [OCTOBER
telophase is shown in fig. 51. The chromosomes seem to remain
distinct here (figs. 51 and 52) and could often be counted after the
nuclear membrane was formed. Fig. 53 shows the metaphase of
the homotypic division; the two spindles being almost at right
angles, one nucleus is cut exactly at the plate and the other shows
almost all of the spindle. The formation of the tetrad is shown in
fig. 54. Different views of the microspores soon after their forma-
tion are shown in figs. 55 and 56. The nucleus divides at once to
form the tube and generative nuclei (figs. 56-59). The wall appar-
ently disappears early, as several gametophytes without a wall
separating the two nuclei were found in these same anthers. The
stages shown in figs. 55-59 come from the same anthers, all the
anthers of this flower being in the same stage.
FERTILIZATION.—The pollen tube comes through the micropyle,
which is usually open (figs. 30, 42, 43), curves around the tip of the
synergid, and seems to empty into one of the synergids below the
notch (fig. 60). In this sac the other synergid is quite dark, and
the tube can be traced to this dark mass. Fertilization has already
taken place, and there are two endosperm nuclei. In fig. 61 the
same dark appearance of one synergid is found, and again the other
synergid is unchanged. Fusion of the sex nuclei has already taken
place; both the egg and the primary endosperm nucleus show much
more chromatin than they do in the mature sac (fig. 43). Several
pollen tubes were seen, all about the same stage. Only one more
will be shown (fig. 62). In this the bending of the tube around the
upper part of the synergid is not so clearly shown, as the section was
not so fortunate in position as that in fig. 60, yet the tortuous course
is quite evident. But especially clear is the emptying of the tube
into one synergid. The contents of this synergid consist of a very
darkly stained mass in which no structure can be distinguished
except one nucleolus, which is quite clear because of its bright red
color in the dark purplish mass. It is probably the nucleolus of the
synergid nucleus. The other synergid is in the next section and is
quite normal in every respect.
GUIGNARD (11) in Nicotiana Tabacum and Datura laevis reports
the pollen tube passing into one synergid and discharging its con-
tents there. JuEL (14) has described a similar passing of the
1912] PACE—PARNASSIA 315
contents of the pollen tube into one synergid in Saxifraga granulata.
Cuopat (3, p. 552) says:
Lorsque le noyau fécondant est entré dans le sac on remarque qu’au moins
lune des synergids perd sa turgescence et se désorganise.
In his fig. 677 he shows a pollen tube which from the drawing
might be either inside or outside of the synergid. In this mass are
three nuclei, one evidently the synergid nucleus. Fig. 63 shows a
sperm cell in each synergid. There seems to be a distinct layer of
fine-grained cytoplasm about each of these nuclei. One synergid
also has another somewhat irregular mass of nuclear stuff which is
probably the tube nucleus. This sac was cut slantingly, so that the
micropyle and filiform apparatus were in another section, but no
trace of the pollen tube was found in this region. Another ovule in
the same section had an embryo of five cells. But only a very few
embryos were present in this ovary, and the other ovules did not
show evidence of fertilization; so that probably only a few pollen
grains had reached the stigma. These two dark synergids, each
containing a sperm cell, might be interpreted as evidence of two
pollen tubes in the same sac. But as there is no other trace of
pollen tubes or other nuclei, and the egg and primary endosperm
nucleus do not have the appearance of having been fertilized, it
seems best to suppose that only one pollen tube has entered and
that it burst just where the two synergids are in contact. In this
Way it would be possible for part of the contents to pass into one
synergid and part into the other. .Both synergids are quite dark
and show little trace of vacuoles, which are quite conspicuous in
mature sacs.
NAWASCHIN (16) says that after the pollen tube passes the ~
micropylar canal and the nucellus of the ovule, and its tip is in
contact with the embryo sac, one of the synergids bursts and pours
part of its contents into the micropyle. This forms a half-empty
tube of this synergid, and the sudden diminution of pressure causes
the pollen tube to burst and its contents are poured out next to this
Synergid into the sac. Then the sperm nuclei begin active move-
ment toward the depression in the “‘ Endospermanlage,’”’ and move
from there to the female cells. In Parnassia it is very evident that
the pollen tube passes around the tip of the synergid without either
316 BOTANICAL GAZETTE [OCTOBER
synergid or pollen tube bursting, and that the tube empties into
the synergid just below the notch. This process itself was not seen,
as unfortunately all my material was too old to show this, even
fertilization having already taken place in every case except one.
But the pollen tubes themselves were unusually clear; they could
often be traced through the entire micropyle to the point where they
entered the synergid. CHopat (3) shows the sex nuclei in various
stages of fusion in his figs. 678-680.
Empryo.—One and two-celled embryos showed nothing un-
usual. The endosperm nucleus usually divides first; only one ex-
ception to this was seen (fig.65). Here there is a five-celled embryo
with the endosperm nucleus still undivided and somewhat amoeboid
in shape, which is also unusual in Parnassia. One sac was seen with
a two-celled embryo and two endosperm nuclei, one near the embryo
and the other near the antipodals, and one synergid still perfect.
Empty pollen tubes are often very persistent in Parnassia. It is
not uncommon to find a pollen tube that can be seen through the
greater part of the micropyle and with the curve at the entrance to
the sac where it passes around the beak of the synergid, but with
little trace of the synergids below this, when the embryo has 20 or
more cells. In the second division in the embryo, the upper cell
again divides in the same plane as the first division, while the lower
cell divides at right angles (fig. 64). Fig. 65 shows the five-celled
embryo. Not many embryos of this stage were seen, but this »
seems to be the usual arrangement of cells. Fig. 66 gives the next
stage, where the upper cell had again divided in the longitudinal
direction. In fig. 67 the dermatogen is differentiated, and a layer
of endosperm about two cells in thickness extends entirely around
the sac next to the wall; in the center are a few free nuclei. Soon
the plerome and periblem are also differentiated, as can be seen from
the end of the embryo in fig. 68. This entire embryo is outlined in
fig. 69 and the plerome is dotted in. The two cotyledons are
already formed, and the embryo now completely fills the upper two-
thirds of the sac, except for a layer of endosperm about two cells
thick around it. The lower third of the sac is filled with endosperm.
Cuopat (3) in his fig. 756 shows embryos from the two-celled stage
to the differentiation of the dermatogen; his figures 756-775 are
similar to my figures 7 5 and 81.
1912] PACE—PARNASSIA | 317
Saxifraga
Several species of Saxifraga, growing in the Botanical Garden in
Bonn, were examined, to be sure that the usual form of this genus
was known. The same methods of fixing and staining were used for
Saxifraga, Heuchera, and Drosera as had been employed with
Parnassia,
JUEL (14) has given a description of Saxifraga granulata which
agrees in all the stages shown with the stages here figured; and I
have examined S. ligulata, S. sponhemica, S. cordifolia, and S.
crassifolia, which seem to be so similar that the same figures could
used for each. Not much work was done with the reduction
division; but the reduced number of chromosomes in S. sponhemica
is about 15. Jurt (14) found this to be about 30 in S. granulata.
These two numbers are rather suggestive, especially since GATES’s
(10) investigation of Oenothera gigas and STRASBURGER’S (23)
discussion of this question.
Nothing unusual was seen in the pollen development of Saxi-
Jraga. The pollen grains are small and with smooth, rather thin
walls. It might be of interest to note that in many of the flowers of
S. cordifolia some of the anthers contained pollen at least twice the
usual diameter, and in some cases as much as four times. In one
flower this large pollen was found in every other anther, the younger
set of stamens all being affected. But not all flowers produced
this large pollen, and it was usually irregular in occurrence when
Present. As all the later flowers were blighted, turning black
before the inflorescence was out of the bud, this peculiarity of the
Pollen was probably due to a fungus; but this was not investigated.
Two young ovules of S. sponhemica from the same ovary are
Shown. F ig. 71 shows the archesporial cell, and fig. 72 a later stage
in which there is one sporogenous cell and the primary parietal cell
has divided. The mother cell stage is shown in fig. 73, with two
parietal cells. In fig. 74 there are three sporogenous cells, only one
of which has reached the mother cell stage; a later stage is shown in
fig. 75. There are three parietal cells above the mother cell in fig.
76. The whole of this ovule is shown in fig. 79. In Saxifraga, so
far as examined, the megaspores are always in a row (fig. 78), and
the fourth one develops the embryo sac. Not so much material
318 BOTANICAL GAZETTE [ocToBER
was examined as in Parnassia, but enough to be sure that the
development of the other megaspores, if it takes place at all, is not
common. The position of the megaspores in the nucellus is shown
in fig. 79. Their great depth in the nucellar tissue is in striking
contrast to Parnassia, where they are immediately below the
epidermis, which is disorganizing at this stage.
Fig. 80 outlines an entire ovule with a two-nucleate embryo sac.
There are no air spaces, the whole ovule being very compact and
much more massive than that of Parnassia. The egg apparatus
of a mature sac is shown in fig. 81. The synergids have a well
developed filiform apparatus and a notch almost if not quite as deep
as that in Parnassia. A diagram of this entire sac is shown in fig.
82. Two of the antipodals had disappeared. The polars have
already fused and the primary endosperm nucleus is near the base
of the sac. This seems to be its usual position in Saxifraga, at least
in the examples I studied. JurEt (14) shows it near the middle or
toward the antipodal region in S. granulata at fertilization. Fig.
83 is a young embryo which has just been differentiated into long
suspensor and embryo proper. Two endosperm nuclei are shown.
Heuchera brixoides
This species corresponds so closely with Saxifraga that only
three figures will be shown. There is usually one mother cell in
Heuchera. One ovule with two mother cells (fig. 84) is shown, 4
later stage (fig. 85) with a large amount of parietal tissue, and @
mature embryo sac (fig. 86). The placentae of Heuchera are like
those of Parnassia, and quite unlike those of Saxifraga.
j Drosera rotundifolia
This material was collected near Bonn. ROSENBERG (19) has
worked out a very interesting chromosome relationship of D.
rotundifolia, D. longifolia, and D. intermedia. In his early paper
(18) he does not figure certain stages which I need for comparison,
only quoting from C. A. PeTERs (17, p. 275):
Each nucellus produces a sporogenous layer of four cells, but no tapetum.
Three cells of the sporogenous tissue soon disintegrate, leaving the fourth,
which is the mother cell of the embryo sac and which aes subsequent cell
division as is usual in angiosperms.
1912] PACE—PARNASSIA 319
I shall give a few figures, therefore, in order to compare them
with Parnassia and Saxifraga. |
The mother cell in synapsis is shown in fig. 87. It will be seen
that like Parnassia and Saxifraga no parietal cells were produced by
the archesporium. This is the commonest condition in Drosera.
But frequently a parietal cell is cut off which divides, as is shown in
fig. 88, giving a row of two parietal cells above the mother cell.
Occasionally more than one sporogenous cell is produced (fig. 89);
but I saw no evidence that more than one embryo sac was produced,
or even that more than one cell reached the mother cell stage. The
usual row of four megaspores resulting from these two positions of
the mother cell are shown in figs. go and g1. Insome instances the
megaspores are not in a row, as ROSENBERG (19) has shown in his
text fig. 27, B, which is similar to fig. 25 in Parnassia. So far as
examined, only the fourth megaspore develops in Drosera. Not so
much material was cut as for Parnassia, but it is at least certain
that the development of the other spores is not common as it is
in Parnassia,
In Drosera, even in the mother cell stage (fig. 87), air spaces
begin to develop in the chalazal region of the ovule. These
spaces are quite large by the time the embryo sac has reached the
two-nucleate stage (fig. 92), and in the mature ovule they are at
least as Strikingly developed as in Parnassia. The embryo sac
Sccupies only the upper third of the nucellus even at maturity,
quite in contrast to Parnassia and Saxifraga. The nucellus also
begins to show its peculiar enlargement of cells. The outer layer of
nucellar cells, except those directly over the embryo sac, increase
€normously in size without increase of cytoplasm or size of nucleus;
the latter lies next to the inner side of the cell. This enlargement
of the nucellar cells, as well as the air spaces, reduces the specific
Sravity of the seed. Duets (5) says:
They are by their constitution capable of floating. HoLzNer states that
the seeds of D. rotundifolia at a temperature of about 20° are capable of floating
for about a month.
In fig. 93 the third division in the sac is shown and enough of the
hucellus to show the differentiation in it. In one nucleus the 10
chromosomes may be counted.
320 BOTANICAL GAZETTE [ocroBER
The mature sac-(fig. 94) has the usual appearance. The syner-
gids have a well developed filiform apparatus and notch. The
former is somewhat more dome-shaped than in Parnassia, where it
is pointed. The synergids are also rather long, reaching almost as
far as the lower edge of theegg. The polar nuclei have already fused.
Fertilization apparently takes place as in Parnassia. The pollen
tube passes around the filiform apparatus and seems to enter one
synergid (fig. 95). Here probably the fusion of the sex nuclei has
already taken place, as only one nucleus can be distinguished in the
lower part of the dark synergid and probably another in the still
darker mass higher up. Fig. 96 is clearer in this respect. A small
bit of the pollen tube can be seen in contact with the filiform
apparatus. This synergid is somewhat darkly stained, but still all
structures are distinct, the notch and two nuclei; these are the
synergid nucleus and the tube nucleus from the pollen tube. The
other synergid is very pale and all the lower part has disappeared.
The fertilized egg has not yet divided, but the primary endosperm
nucleus is in mitosis; the spindle fibers are forming. So far as
examined, this nucleus always divides before the fertilized egg 10
Drosera. Many cases were seen with two endosperm nuclei and .
the egg still undivided.
Discussion
Three other genera of the Saxifragaceae have been more Or less
completely worked out. EIcHINGER (7) figures an ovule of Chrysos-
plenium with mature embryo sac that has three layers of nucellar
tissue above the sac. In Astilbe WEBB (25) reports several arche-
sporial cells and one or even two or three megaspore mother cells
beginning to divide. The embryo sac is deep in the nucellar tissue,
but no filiform apparatus is shown. The embryo has a suspensor of
several cells. FISCHER (9) in Ribes aureum shows ovule development
similar to that of Saxifraga, except that the filiform apparatus is not
shown. TISCHLER (24) in a mature embryo sac of Ribes sangu-
nineum shows pointed synergids but no filiform apparatus or notch.
These cases may indicate that these three genera do not have the
filiform apparatus and notch. But it is also possible that the
material studied was not at the right age to show these best, or was
not cut to the best advantage for these particular structures.
s
1912] PACE—PARNASSIA 321
In a recent number of Das Pflanzenreich on Droseraceae, DIELS
(5) says, in discussing relationships:
* Die mehrfach den Droseraceen angeschlossene Gattung Parnassia wird
neuerdings nach dem Vorgang von ADAMSON, ENDLICHER, LINDLEY, und
Payer, allgemein ausgeschlossen nachdem Drunk in seine griindlich
rung der Frage (Linnaea 39:293. 1875) auf die gewichtigen Be enken
practischer Natur’ hingewiesen hatte, die einer Uberfiihrung von Parnassia zu
den Droseraceen im Wege stehen.
ENGLER (8), in a note in connection with the Sarraceniaceae,
concludes with these words:
Die Droseraceae nihere sich dadurch in diagrammatische Beziehung
manchen Saxifragaceae, von denen Parnassia auch allgemein den Droseraceae
zugerechnet wurde. .
The following is a rather free translation of EICHINGER’s (6)
summary of the characters which differentiate Parnassia from
Droseraceae:
1. Germination —Parnassia shows normal germination; cotyledons do not
function as an absorbing apparatus. The Droseraceae have no primary root;
cotyledons have more or less the function of an absorbing apparatus.
2. Leaf structure—The nervature is different. Parnassia possesses a
typical leaf structure, in the epidermis tannin; the Droseraceae have no typical
assimilation tissue and often chlorophyll in the epidermis, and always more or
less modified glands.
3- Flowers.—All species of Parnassia have staminodia; the Droseraceae
have not. ae
4. Befruchtungsvorgang (apparently pollination).—It is apparently —
in species of Parnassia, has no analogy to the Droseraceae, but has to Saxifraga.
- Androecium.—Parnassia possesses small simple pollen grains; all of the
Droseraceae have tetrads. “1s
- Gynaecium.—Parnassia has stalked placentae, a very striking ene
ductive tissue, the nucellus is small-celled and soon vanishes, the embryo is
well formed and fills the almost endospermless seed. Drosera at least has flat
_ Placentae without conductive tissue, characteristically differentiated nucellus,
and all of the Droseraceae have small, round, imperfect embryos and much
endosperm.
HALLIER (12) says:
Under the Saxifragaceae the genus Parnassia takes an isolated place.
According to its peculiar habit, its low rosette of long-petioled oval leaves, its
one-flowered, long, almost leafless flower-stalk, and the lack of hairs, it evi-
dently belongs not to the Saxifragaceae, but in ENGLER’s order Sarraceniales,
which, through the f t f oval, long-petioled, fleshy leaf blades,
(as ¢
322 BOTANICAL GAZETTE [OCTOBER
long, one or few-flowered peduncle, fleshy, white, oval floral leaves, and its
great predilection for wet or moist places, reveals its descent from the relatives
of the Nymphaeaceae, and it manifestly has nothing to do with the Saxi-
fragaceae, which are nearly related to the Rosaceae. Apart from the peculiar
staminodia, which are evidently morphologically equivalent to the staminodia
of many Nymphaeaceae, the fibers (Faden) in the Rafflesia, flower, and the
corona of Passiflora, Parnassia fits closely to Drosera through its leaf-rosette,
its long, almost leafless shaft, the calyx, the five beautiful white petals, the
sessile stigmas, the numerous parietal ovules, the method of capsule opening,
the small oblong seed, rich in endosperm, and moist habitat. Through its
four-leaved (four-carpellate) seed coat it approaches Nepenthes also.
A summary of the parts studied by way of comparison may
be helpful. °
1. The ovule of Parnassia and Drosera are of the same shape,
and both have large air spaces developed. That of Saxifraga is
very compact and much thicker, and with thicker integuments.
2. In Parnassia the archesporium of the ovules is hypodermal
and forms no new cells above it. Drosera usually develops in the
same way, but sometimes there is a single layer of cells between the
mother cell and the epidermis. All the Saxifragaceae studied form
the archesporium in the same way, but by the time the mother cell
stage is reached there are several layers of cells above it.
3. In Parnassia the embryo sac comes to lie next to the integu-
ment except the very basal portion, all the nucellar cells above and
at the side having been destroyed. In Drosera the nucellar cells
above the sac have a squeezed appearance and are occasionally
destroyed completely. At the side and below the sac the layer of
cells next the epidermis enlarge very greatly, giving the nucellus of
Drosera a very peculiar appearance. This may be only another
means of decreasing the specific gravity of the seed. The sac of the
Saxifragaceae has several layers of nucellar cells above it.
4. All three genera have an enormous development of the
filiform apparatus of the synergids, and the notch is also strikingly
developed. The filiform apparatus is pointed in Parnassia and
Saxifragaceae, and less pointed or more dome-shaped in Drosera.
5: € primary endosperm nucleus in Parnassia and in
Drosera is immediately below the egg. In Saxifraga it is almost in
contact with the antipodals, and in Heuchera it is far below the egs-
1912] PACE—PARNASSIA 323
6. The haploid chromosome number in Parnassia and in
Drosera rotundifolia is 10, in Saxifraga sponhemica about 15, and in
S. granulata about 30.
7- In Parnassia and S. granulata the pollen tube empties into
one synergid, and apparently the same is true in Drosera.
With reference to the systematic position, EICHINGER (6) says
that the joining of Parnassia to the Droseraceae would completely
destroy the unity of this family. Its principal characteristic would
be lost. The failure of a primary root, the defective differentiation
of the assimilation tissue, the stipular structures, which recall the
intra-ovarian scales of many water plants, the numerous secretion
glands, the common appearance of cleistogamous and autogamous
flowers, the high capability for regeneration, and the appearance
of vegetative buds are most important. In Parnassia no such
relation to water plants is found. If one looks for a suitable place in
the system for Parnassia, one must admit that it had better remain
with the Saxifragaceae. This family has at present so little unity
that Parnassia makes no break in its systematic characteristics.
In discussing the same question, HALLIER (13) says: according to
the pronounced monocotyledonous type of venation of the sepals
and petals, it seems to me to stand not very far from the point of
departure of the monocotyledons and as the representative of a
Separate family, the Parnassiaceae, to belong near the Ranuncu-
laceae, Nymphaeaceae, Droseraceae, and Sarraceniaceae. From
the Saxifragaceae, in which ENGLER (18) has placed it, it is differ-
entiated by the harp-shaped branching of the veins in the sepals,
the large, long Podophyllum and Sarracenia-like anthers, and the
_ Ovule, which has a slender nucellus, as in other relatives of the
DStratickan:
After working over my material, I am of the opinion that
Parnassia is much more closely related to the Droseraceae than to
the Saxifragaceae, and that it should at least be put in the same
order with the Droseraceae. For as shown above, Drosera and
Parnassia are quite alike in their ovules and in embryo sac develop-
ment, except as to the nucellus, in which neither is like Saxifraga.
They differ also in that Parnassia has stalked placentae, while
Drosera has not. Drosera has pollen grains in tetrads and Parnassia
324 BOTANICAL GAZETTE [OCTOBER
has them separate. But in neither of these characters does Par-
nassia agree with Saxifraga, whose placentae are still more dis-
similar and whose pollen grains are perfectly smooth.
BAYLOR UNIVERSITY
Waco, TEXAS
LITERATURE CITED
1. CHAMBERLAIN, C. J., es embryo sac of Aster novae-angliae. Bor. GAz.
20: 205-212. pis. 15, I Q5.
ai 2 cerns S oh life history of Salix. Bot. Gaz. 23:147-179.
pls. iif.
3. CHODAT, fie des oe 1907.
4. COULTER and CHAMBERLAIN, Morphology of angiosperms. 1903.
5. Diets, L., Droseraceae in Sec Pflanzenreich von A. ENGLER. 1906.
6. EicHincer, A., Beitrige zur Kenntnis und systematfschen Stellung der
thoi Pardéssia. Bot. Centralbl. 23: 298-317. jigs. 21. 190
, Vergleichende ees von Adon id Chryso-
ek Bay. Bot. Gesells. 1-27. pls. 1- :
8. EncteER, A., und PRrantt, K., Die acai Pianwentatnilicn. Leipzig.
9. Fiscner, A., Zur Kenntnis der Embryosackentwicklung einiger Angio-
spermen. ten Zeitsch. Naturw. 14:1-44. pls. 1-4. 1880.
10. GATES, R. R., The stature ie chromosomes of Ocenothera gigas. Arch.
Zellforsch. 3: 525-552. :
11. GUIGNARD, L., La double teondation chez les Solanées. Jour. Botanique
16: 145-167. figs. 45. 190
12. Haturer, H., Uber die Vermunteclslaschaliniee der Tubifloren und
Ebenalen, aon ped bccn Ursprung der Sympetalen und Apetalen.
Abhandl. Naturwiss 16: 1-112. roor.
13. ———, Uber Juliana, etc. Mews Beitrage zur Stamensgeschichte der
Dicotyledonen. Bot. Centralbl. 23:81—265. 1908.
14. JueLt, H. O., Studien iiber die Entwicklungsgeschichte von cate
granulata. Nov. Act. Reg. Soc. Sci. Upsal. 9: 1-41. pls. 1-4. 1907-
16. Nawascutn, S., Uber selbstindige Bewegungsvormbgen der Spermakerne
bei einigen Acennen: Oesterr. Bot. Zeitsch. 1221-11. pl. 8. 1909.
17. Peters, C. A., Reproductive organs and embryology of Drosera. Proc.
r. Ass kde. Sci. 1897-1898.
18, Cae aees O., Physiologisch-cytologische Untersuchungen tiber Drosera
ee se 126, pls. 2. 18
gische und metphiolopische studien an Drosera longifolia
aie: grat Svensk. Vetensk. Handl. 43:1-64. pls. 1-4. Sigs. 33-
1909.
19.
1912] PACE—PARNASSIA 325
20. SHREVE, F., The nea and anatomy of Sarracenia purpurea.
Bort. Gaz. ‘eas 107-126. pls. 3-
21. STRASBURGER, E. we Sasuhon. ia "Daphne. Ber. Deutsch. Bot. Gesells.
3105-113. pl. 9. 1885.
22. , Die heii und die Gymnospermen. Jena. 1879.
23. , Chromosomenzahl. Flora 100:389-446. pl. 6. 1910.
24. TISCHLER, G., Uber Embryosack-Obliteration bei Bastardpflanzen. Beih.
Bot. Centralbl. 2: 408-420. pl. 5. 1903.
25. WEsB, J. E., A morphological study of cot — and embryo of (Spiraea)
(Astilbe). Bor. GAz. 33: 451-460. figs.
26. Von WetrtstTEIN, R. R., Handbuch der eae Botanik.
EXPLANATION OF PLATES XIV-XVII
All figures except the diagram in fig. 70 were drawn with the aid of the
camera lucida; Spencer ocular no. 4 and 4 mm. objective were used for figs. 5,
3°; 45, 46, 47, 48, 67, 68, 77, 79, 80, and 92; ocular no. 4 and 16 mm. objective
were used for fig. 69; all others were drawn with ocular no. 4, 1.5 mm. (oil
objective.
The abbreviations used are as follows: €, egg; m, megaspore; ¢, male
nucleus; p, pollen tube; s, synergid; #, tube nucleus.
Parnassia palustris
Fic. 1.—Young ovule with three large hypodermal cells; two shown in the
drawing: the third is just back of these two.
Fic. 2.—A somewhat older ovule with four large cells in a row, evidently
derived from a single hypodermal cell by two successive divisions.
Fic. 3.—A different arrangement of the large group of cells, one cell in
mitosis, showing 20 chromosomes; from the same ovary as fig. 5.
Fic. 4.—Sporogenous cell diferiutinted as shown by size and stain; the
inner integument is beginning to develo
Fic. 5.—Synapsis and beginning of wale r int nt.
Fic. 6.—Two sporogenous cells; the larger one already in synapsis.
Fic. 7.—Two sporogenous cells of approximately the same size; the two
cells were in the same section, one lying above the other; the larger cell has the
nucleus in synapsis, the other one in an earlier stage.
Fic. 8.—After recovering from synapsis; spirem still very long.
Fic. 9.—Ten short chromosomes; the double character can be clearly seen
in several.
FIG. 10.—The two daughter cells with chromosomes formed for the second
division.
Fic. 1r.—The micropylar daughter cell in same stage as fig. 10; the
chalazal daughter cell has nucleus with spindle.
Fic. 12.—Both daughter cells in the telophase stage; in the micropylar
cell one a failed to reach the pole and so is omitted from the mega-
spore nucleu
-
326 BOTANICAL GAZETTE [OCTOBER
IG. 13.—Four megaspores, apparently all increased in size but the first
deitineiae and the second and fourth larger than the t
Fic. 14.—A different arrangement of the four megaspores, probably
i more often than that shown in fig. 1
G. 15.—Approaches still more nearly re cout tetrad arrangement.
ri IGS. 16—-22.—The variations in the early stages of the megaspores.
. 23.—Apparently five megaspores; one nucleus is very small and seems
to nie only one chromosome, probably resulting from an abnormal division
like that in fig. 12.
Fic. 24.—Third and fourth megaspores developing; the nucellar cells
surrounding these are already showing signs of disintegration, and only the
three at the base are still normal in appearance.
Fic. 25.—In this case also the epidermal cells are becoming pale, especially
over the upper vigorous megaspore, which appears to be more active than
the fourth.
Fic. 26.—The third megaspore forming the embryo sac and in mitosis for
the first division; the epidermal layer partly disorganized, leaving the sac in
contact with the inner integument and an Aa micropyle.
Fic. 27.—Two-celled sac formed from second megaspore; the third
megaspore also heaps the alias layer still further disorganized.
Fic. 28.—Embryo sac formed from the fourth megaspore; first division
showing 10 chromosomes, the other megaspores represented by a formless mass
above; epidermal layer still perfect; integuments well advanced.
Fic. 29.—All the epidermal layer, especially the two upper cells of the
nucellus, lighter than the adjacent integument cells; two-celled sac from the
fourth megaspore; the second and third megaspores have persisted longer
than usual.
Fic. 30.—The entire ovule with two-celled embryo sac; ovule with loose
spongy tissue at base; nucellus entirely lacking over greater part of sac. :
IG. 31.—Two-celled sac with nuclei in mitosis for the second division;
the 10 chromosomes may be seen in the upper nucleus; the upper half of the
sac is in contact with the integument, the nucellus having entirely disappeared
from this region.
Fic. 32.—Similar to fig. 31, but the lower nucleus somewhat in advance of
the upper; in the lower a sears are short and thick, while in the
upper the spirem is segmen
Fic. 33.—Spindles for ied second mitosis in the embryo sac; this sac
Big oy from the second megaspore; the third megaspore also developing.
G. 34.—The four-nucleate embryo sac with the spirems more of less
completly segmented for the third division.
G. 35.—Spindles for the third division in the embryo sac; in the uppet
part of the sac one spindle is almost at right angles to the paper.
Fic, 36.—Eight-nucleate sac soon after the third division.
1912] PACE—PARNASSIA 327
Fic. 37.—Embryo sac soon after the organization of the egg apparatus, the
egg being just under the synergids; only the lower part of : with part of its
nucleus can be seen; polars not yet in contact
Fic. 38. cee end of sac, slightly aides than in preceding figure; one
synergid has vacuoles above the nucleus, the other has them below it; the
so-called filiform apparatus beginning to be differentiated near the tip of the
synergids.
Fic. 39.—From older sac; the synergids have unusually large vacuoles,
both above the nuclei; polars are in contact.
Fic. 40.—The polar nuclei have fused; vacuoles below the nuclei in the
Aah the filiform apparatus well developed and forming a caplike
struct
Fic —This sac was cut at right angles to the one above, showing
the aL = the egg, but only one synergid; this ovary still contained
four-celled sacs.
Fic. 42.—Upper end of mature embryo sac; the unusual development of
the filiform apparatus clearly shown; the inner layer of cells of the integument
disintegrating.
Fic. 43.—Same stage as the preceding, but with the egg apparatus still
farther up in the micropylar region; some of the cells of the integument
entirely disorganized.
Fic. 44.—The entire egg apparatus in the micropyle, the adjacent cells of
the integument having disappeared and the egg apparatus having a squeezed
ak bags
G. 45.—The upper part of an ovule outlined; the egg apparatus in the
ae one synergid lying above the other
Fic. 46.—Egg apparatus in the ite. but the pata Hg so pressed
together jk it is not possible to differentiate them
Fic. 47.—A diagram of the upper part of an gpule; one synergid has the
upper Bay entirely out of the ovule, its lower end overlapping slightly the
upper part of the other synergid.
Fic. 48.—The entire egg apparatus just at the entrance of the micropyle,
giving the appearance of a pollen tube; the polar nuclei are in contact but
have not yet fused,
Fic. 49.—A few pollen mother cells; in two of these synapsis is perfect,
in the rena almost so
Fic. 50.—The 10 chaccnpliceaes may be counted in this pollen mother cell.
Fic. 51.—Telophase of the first division.
Fic. 52.—Telophase of the first division in which the ro chromosomes are
still niga a
G. 53.—Metaphase of the second division, one nucleus showing the
sini and the other being cut parallel with the nuclear plate and showing the
to chromosomes.
328 BOTANICAL GAZETTE [OCTOBER
Fic. 54.—The tetrad with a few spindle fibers still present.
Fies. 55-59.—Stages in the division of the pollen grain into vegetative
and ebaeg a in fig. 57 the 10 chromosomes are shown.
Fic. 60.—Fertilization: the pollen tube curved around the upper part of
the synergid, an is quite dark; ila the sperm has already fused with
the egg; the endosperm of this sac is two-nucleate.
Fic. 61.—The male nuclei have already fused with the egg and the primary
endosperm nucleus; the dark mass underneath the synergid and outlined
ieneh it is the other synergid and some material from the pollen tube.
Fic. 62.—Pollen tube entering one synergid; the other synergid is just
back of this one; fertilization has already taken place; the endosperm nucleus
has divided, the other endosperm nucleus being near the antipodals.
1G. 63.—The upper end of an embryo sac; in each synergid is a synergid
nucleus and another smaller dense nucleus (a mise nucleus with fine-grained
cytoplasm around it); one synergid has a third nuclear mass, the tube nucleus.
Fic. 6
Fic. 66.—An older embryo with traces of a synergid and showing one
endosperm nucleus.
Fic. 67.—Older embryo with dermatogen layer differentiated; the endo-
sperm forms a layer about two cells in thickness all around the sac — a few
free nuclei in the interior, especially around the lower end of the embry:
1G. 68.—The basal part of older embryo, showing dermatogen, venue
and perilous:
1G. 69.—The same embryo outlined; a typical straight dicotyledonous
embryo which fills about two-thirds of the sac except for the layer of endosperm
about two cells in thickness; the other third of the sac is filled with endosperm.
Fic. 70.—A diagram of an abnormal flower; one anther has developed
on a’ staminodium, two are normal, the others, more or less imperfect, are on
the carpels, which are not so completely united as usual.
Saxtifraga
Fic. 71.—S. sponhemica: outer half of young ovule showing archesporial
Hl.
Fic. 72.—Same: the archesporial cell divided.
Fic. 73.—S. crassifolia: one mother c
Fic. 74.—Same: one mother cell, a er other ee @ are quite large and
stain like sporogenous ce
Fic. 75.—S. tndijolios one sporogenous cell.
Fic. 76.—S. crassifolia: mother cell with three ay cells.
Fic. 77.—Same: entire ovule with less magnifica
Fic. 78.—S. ligulata: megaspores; the lower are alee for the embry
Fic. 79.—Same: some megaspores showing nucellar tissue above.
PLATE XIV
BOTANICAL GAZETTE, LIV
PACE on PARNASSIA
PLATE XV
BOTANICAL GAZETTE, LIV
PACE on PARNASSIA
PLATE XVI
BOTANICAL GAZETTE, LIV
&. Siok) oot
She) ~~ @
. KO) } (25
Boe
ORE
Ny
CO
Q
Qo
OID ‘s)
@Ney, \p
aS
LCs
Moo!
PACE on PARNASSIA
BOTANICAL GAZETTE, LIV PLATE XVII
PACE on PARNASSIA
1912] . PACE—PARNASSIA 320
Fic. 80.—Same: a diagram of an entire ovule with two-nucleate sac;
very compact tissue throughout the entire ovule.
Fic. 81.—S. cordifolia: egg apparatus.
Fic. 82.—Diagram of the same sac, showing one antipodal and the polars
already fused near the base of the sac.
Fic. 83.—S. crassifolia: embryo and two endosperm nuclei.
Heuchera brixoides
Fic. 84.—Part of ovule showing two mother cells which are not exactly
parallel and overlap slightly.
85.—Mother cell after synapsis and deep in nucellar tissu
Fic. 86.—Mature embryo sac; filiform apparatus and notch seat develiped
in the synergids.
Drosera rotundifolia
Fic. 87.—Mother cell.
Fic. 88.—Mother cell with two hypodermal cells abov:
Fic. 89.—At least two sporogenous cells, one of which has passed the
synapsis stage.
Fic. 90.—Megaspores developed from a mother cell like that in fig. 87;
the fourth megaspore has begun to develop the aeinye sac, the other three are
almost completely disorganized.
Fic. 91.—Similar megaspores, but developed from a mother cell like that
in fig. 88.
Fic. 92.—An ovule with two-nucleate embryo sac; large air spaces and
much spongy tissue in the lower part of the ovule; nucellar tissue with very
small cells in center and very large ones next to the integument except just over
the sac.
IG. 93.—The third division in the embryo sac; in the upper nucleus the
10 chromosomes may be counted; the small nucellar cells just over the sac and
the very large ones toward the base and the small ones in the center of the
nucellus below the sac give the Drosera nucellus a very unusual appearance.
Fic. 94.—Mature embryo sac; the synergids have a well developed notch
and a somewhat dome-shaped filiform apparatus; the polars have already fused
Fic. 95.—An embryo sac with pollen tube passing around the éRiccm
apparatus and apparently emptying into the synergid; probably the sex nuclei
have already fused, but the e mass is so indistinct one cannot be sure of the
tag of the synergid re
G. 96.—One synergid hws still a trace of the nucleus and the filiform
sien the other synergid shows the notch and above a bit of the pollen
tube; in the lower part are two nuclei, probably the synergid nucleus and tube
nucleus; the sex nuclei have fused and the endosperm nucleus is in mitosis.
DEVELOPMENT OF THE MICROSPORANGIA AND
MICROSPORES OF ABUTILON THEOPHRASTI
V. LANTIS
(WITH TWELVE FIGURES)
The material used in this study was collected during September
and October 1910. While many killing and fixing fluids were
tried, Flemming’s weaker solution proved the most satisfactory and
was therefore the most generally used.
Because of the excessive development of sclerenchymatous
tissue in this form, much difficulty was first experienced in sec-
tioning. This was obviated, however, by infiltrating and imbed-
ing in JOHNSTON’s paraffin-asphalt-rubber mixture (11, 16), which
consists of 99 parts of paraffin (desired grade) in which has been
melted enough asphalt (mineral rubber) to give the paraffin an
amber color, and one part of crude india rubber. This method,
in that it has proved so satisfactory, deserves a more general
use among botanists. Many stains were tried, but Heidenheim’s
iron-alum hematoxylin, with orange G as a contrast stain, gave
the best results.
The stamens of Abutilon Theophrasti Medic. are epipetalous,
monadalphous, and branching. Occasionally the branches of the
filaments are so short that the two anthers set back to back, and
the two might be taken for one anther in a hasty examination.
In longitudinal section the anthers are more or less crescentic
in form, while a cross-section shows them to be two-rowed (fig. 5):
In this respect it is very much like Althaea rosea Cav. (2, 4) and
Tilia ulmifolia (7). It is not at all uncommon to see one lobe
much longer and more crescentic than the other. The filament 1S
attached to the middle of the inner side of the crescent-shaped
anther. Dehiscence takes place by means of one longitudinal
fissure.
There are two crescent-shaped microsporangia in each anther,
one in each of the two lobes. With respect to the number of
Botanical Gazette, vol. 54] [33°
1912] LANTIS—ABUTILON THEOPHRASTI che
microsporangia in an anther, Abutilon resembles Althaca (2, 4),
Hamamelis (13), Elodea (12), the Asclepiadaceae, ete.
In cross-section the archesporium is a single hypodermal cell
(fig. 1). An apparent exception to this was observed in a few
cases where two or three hypodermal cells, because of their size
and reaction to stains, might be considered archesporial in their
Possibilities. The subsequent history of the anther, however,
shows that there is only one true archesporial cell as seen in cross-
section. While-a longitudinal section of the archesporium was
not observed, it is very evident that it consists of a single row of
several cells, since such a section shows the primary parietal and
Primary sporogenous cells lying in single rows the full length
of the anther (fig. 2). This condition in Abutilon agrees with
that reported for the Malvaceae and most Compositae, and also
for Gaura (14). The archesporial cells divide, as usual, by peri-
clinal walls to form the primary parietal and primary sporogenous
cells (fig. 4);
The primary sporogenous cells initiate two successive divisions,
one radial and the other periclinal (figs. 4 and 5). Each primary
Sporogenous cell, therefore, as a rule produces only four mother
cells, these four cells being almost regularly shown in a cross-
section of the microsporangium (fig. 5). Thus there is quite a
contrast between Abutilon and Althaea rosea (2), since in the latter
only a single mother cell is usually to be found in a cross-section
of the microsporangium, and in Malva also the mother cell is
Teported to develop directly from the primary sporogenous cell.
: As may be seen from fig. 4, there are usually two parietal layers
in the stage immediately preceding the formation of the mother
cells. Fig. 5 shows the spore mother cell just previous to the
tetrad formation. At this stage there are three parietal layers
including the tapetum, which is well developed. In its origin the
tapetum is like that of Asclepias Cornuti (10), Silphium (9),
and other forms; and the same account is evidently true for
Althaea, as may be judged from Sacus’s figure (2, fig. 377). The
tapetum reaches its highest development about the time of the
tetrad formation, as is true in most angiosperms. Its develop-
ment is much later than that of the tapetum of Euphorbia (8).
332 BOTANICAL GAZETTE [OCTOBER
At about the time the mother cells are dividing or a little
earlier, the nuclei of some of the tapetal cells divide without the
formation of cell walls, and tapetal cells with one, two, or three
nuclei are found, being much like those described for Hamamelis
(13), Ipomoea purpurea (19), and Ulmus (15) in this respect.
\ | ee
WEroLS)
CREPES
ey
ORI
OSs cp
Beene
ry
ais
Ly
&
rae, 2 a
SSR
Source
PEt
a gE
Fics. I-I2.—Fig. 1, cross-section of the anther showing archesporium; fig. 2,
primary sporogenous and primary parietal cells in longitudinal section; fig. 3, primary
Sporogenous cell and plate of parietal cells in cross-section ; fig. 4, two daughter cells
of primary sporogenous cell in cross-section; fig. 5, cross-section of spore mother cells;
fig. 6, longitudinal section of spore mother cells; fig. 7, first division of spore mother
cell; fig. 8, two-celled stage of spore mother cell; fig. 9, second division of spore
ae cell; fig. 10, tetrad, early stage; fig. 11, later stage of tetrad; fig. 12, mature
len grain.
1912] LANTIS—ABUTILON THEOPHRASTI 333
The tapetal cells having two or three nuclei are generally more
or less elongated (fig. 5).
The spore mother cell is a much prolonged stage, and the second
reduction division follows very closely after the first, no walls
being formed until after the four nuclei have appeared (figs. 8
and 9), a condition characteristic of the dicotyledons. The
tetrad is tetrahedral in arrangement (figs. ro and 11), no exceptions
being observed.
Special study was not made of the composition of the wall
of the developing microspores, but evidently it is similar to the
microspore walls of Althaea (6), Malva (5), and Ipomoea (19).
Since the tapetum reached its highest development during the
formation of the tetrad, the mother cells do not become isolated
early, but remain intact as in Althaea (1,2). While the spore walls
are being formed, the tapetum begins to disorganize, but does not
entirely disappear until the pollen grains are practically mature.
In this respect Abutilon resembles Oenothera (17), Gaura Lind-
heimeri (14), etc.
The mature pollen grain is spherical, has both intine and exine
well developed, and is covered with spines (fig. 12). Only two
nuclei, the tube nucleus and the generative nucleus, were found in
the mature pollen grain.
Summary
Abutilon Theophrasti shows the single row of archesporial cells
that has been reported for the other two investigated species of
Malvaceae, and in the formation of primary parietal and primary
Sporogenous layers there is also great similarity.
In Abutilon, however, each primary sporogenous cell produces
four mother cells, while in the other Malvaceae studied only one
is formed. ;
The mother cell stage in Abutilon persists until three parietal
layers, the inner being a well developed tapetum, are fully formed,
after which the characteristic heterotypic and homotypic divisions
take place rapidly. il
This period of tetrad formation is marked by a multiplication
of nuclei in the tapetal cells.
334 BOTANICAL GAZETTE [OCTOBER
The arrangement of the microspores in the tetrad is tetrahedral
and very regular. The tapetum continues to inclose the micro-
spores until they develop their own cell walls and the wall of the
mother cell disorganizes, when the tapetal cells gradually disappear.
This long persistence of the tapetum is also true of Althaea rosea.
The spherical pollen grain of Abutilon agrees with that of other
described Malvaceae in the number of nuclei and the structure and
composition of the walls.
This work has been done in the Botanical Laboratory of the
University of Cincinnati, under the direction of Professor H. M.
BENEDICT, whom the writer wishes to thank for suggestions and
criticisms. Much of the literature was reviewed at the Lloyd
Library of Cincinnati, and the writer desires to acknowledge favors
received from Mr. Wm. HoLpen, the librarian.
UNIVERSITY oF CINCINNATI
LITERATURE CITED
1. Scwacut, H., Die Pflanzenzelle. Berlin. 1852. pp. 58-64. pls. 6. figs. 14-
23.
2. SAcHs, J., Textbook of Botany. English Translation. Oxford. 1882.
PP. 546-556.
3. StrasBuRGER, E., Uber den Bau und das Wachsthum der Zellhdute.
1882. p. 89. ied
4. GOEBEL, K., Outlines of classification and special morphology. Oxtor
5. Srraspurcer, E., Uber das Wachsthum vegetabilischer Zellhaute.
Hist. Beitrige. Jena. 1880.
6. Manew, L., Pineda sur le developpement du pollen. Bull. Soc.
Bot. France 36:301. 1
7. Kerner, A., The aster ge of plants. English translation. New
York. 1895. 2*:87-88. figs. P
8. Lyon, F. M., Life history at Euphorbia corollata. Bor. Gaz. 25 3418-420.
pls. 22-24. 1898.
9. MERRELL, W. B., A contribution to the life history of Silphium. Bor.
Gaz. 29:99-133. pls. 3-10. 1900
to, Frye, T. C., Development of rae pollen in some Asclepiadaceae. Bor.
Gaz. 322325-331. pls. 13. 190 1
11. Jounston, J. B., An imbetig medium for brittle objects. Jour. App!
Micr. 6: 2662-2663. 190
1912] LANTIS—ABUTILON THEOPHRASTI 335
12. Wy.iz, R. B., The morphology of Elodea canadensis. Bot. GAZ. 37:
—22. pls. 1-4. 1904.
13. SHOEMAKER, D. M., On the development of Hamamelis virginiana. Bor.
GAZ. 39: 248-266. pls. 6, 7. 1905.
14. Breer, R., On the development of the pollen grain noe anther of some
Hemaiceas: Beih. Bot. Centralbl. 19: 286-313. pls. 3-5. 10905.
15. SHattuck, C. H., A rebar study of Ulmus americana. Bot.
GAZ. 40: 209-223. pls. 7-0. i
16. Guyver, M. F., Animal ate Hes Chicago. 1906. p
17. Gates, R. R, Pollen development in hybrids of Bailes lataXO.
Lamarckiana sad its relation to mutation. Bor. Gaz. 43:81-116. pls.
2-4. 1907.
18. COULTER and CHAMBERLAIN, Morphology of angiosperms. New York.
1909.
19. BEER, R., Studies in spore development. Ann. Botany 25:199-215.
pls. 13. 1911.
BRIEFER ARTICLES
ARTIFICIAL PRODUCTION OF ALEURONE GRAINS
_ (WITH ONE FIGURE)
As is well known, aleurone grains consist mainly of protein material
which may be wholly amorphous or partly amorphous and partly
crystalline. .In the latter case each grain consists typically of a crystal
of protein (crystalloid), and an envelope of amorphous protein material
whose outer layer may be differentiated from the rest. There is usually
included in the envelope a globule of mineral matter or organic material
combined with mineral matter (globoid). The variations occurring
in different plants have been fully described by PFEFFER."
Each grain is laid down in a vacuole in the protoplasm through the
activity of the protoplasm itself. Its manufacture is therefore a dis-
tinctly vital process. It is the object of this paper to show that bodies of
the same structure may be produced artificially. The resemblance is
so striking as to leave little doubt that the essential features of the
natural process have been successfully imitated.
The first step in the procedure is the preparation of protein accord-
ing to the following method of OsBorNE.? Half a pound of Bertholletia
nuts, after the shells have been removed, are ground into a pulp.
fatty material is then removed by repeated thorough treatments with
ether, the small portion of the solvent which remains in the solid after
the final decantation being allowed to evaporate completely. To the
dry residue is added four or five times its volume of 10 per cent NaCl
solution in which it stands some hours. Frequent shaking accelerates
the dissolving of the protein. The solution of protein is then decanted
and thoroughly filtered. At first the finer particles come through,
but on repeated filtering through the same paper there results an abso-
lutely clear liquid which microscopic examination shows to be without
particles of any kind. This clear filtrate is placed in a dialyzer, and
after some hours the sodium chloride is sufficiently removed to cause
the precipitation of the protein.
Most of the protein is precipitated as clear, well formed crystals
of the hexagonal system. Their thickness is usually about one-sixth
' PrerFeR, W., Jahrb. Wiss. Bot. 8: 429. 1872.
* OsBornE, T. B., Amer. Chem. Jour. 14:622. 1892.
Botanical Gazette, vol. 54] [330
°
Igt2] BRIEFER ARTICLES 337
of their width. Truncated crystals are common, especially those in
which one side is about half as long as the opposite side.
Among the naked crystals are others which are furnished with an
envelope (fig. 1, a, b, g); the whole then resembles an aleurone grain.
The inclosed crystals may resemble any of the free forms, but are usually
complete hexagonal crystals. They may also be of various sizes, but
are usually about the size of the natural aleurone grain. Rarely more
than one enters into the composition of a single grain (fig. 1, #), as
happens also in some kinds of
natural grains,
The envelope varies in thick- ©) © =) oO
ness independently of the size of a b e a
the ctystal. It is usually arranged
symmetrically about the latter, but
the truncated crystals have a tend-
ency to occur at one side. The out-
line of the grain is then globular or
slightly elliptical, but not angular.
Occasionally the outermost layer
of the envelope differs from the
rest in being more opaque and
slightly granular (fig. 1, g), when it
takes the form of a narrow but dis-
Unct membrane. This resembles
the similar structure sometimes
found in natural aleurone grains.
In an experiment in which some
Oo © 6 ®&
Ui: See th ae
1G. 1.—Artificial aleurone grains: a,
protein crystal surrounded by an amor-
phous protein envelope in which is in-
cluded a drop of oil which in size and posi-
tion resembles a globoid; b, similar body
without an oil drop; c-h, various forms of
crystals resembling those which occur in
natural aleurone grains; g, the amor-
1 7 oe © 4:4. 5 Ne Pee | +
p I
layer such as occurs in some natural
grains; h, grain containing three crystals,
a condition sometimes found in natural
grains.
fatty matter had not been removed
by the ether, many extremely small oil droplets came through the filter
and were deposited with the artificial grains. A small number of these
had been incorporated into the grains, each of which then consisted of
a crystal, an oil droplet, and an envelope. The oil droplet thus resembled
the globoid of the natural aleurone grain and the whole artificial grain
Was extremely similar in appearance to the natural one. In view of this
it Seems very probable that artificial globoids could easily be produced
as inclusions in the artificial aleurone grains by causing dissolved globoid
material to precipitate during the formation of the protein crystals.
But this did not seem to be sufficiently important to warrant any
Special effort directed to this end, particularly as globoids do not always
accompany the crystals in natural aleurone grains.
338 BOTANICAL GAZETTE [OCTOBER
The yield of artificial grains varies exceedingly in different experi-
ments. Though two experiments may be performed apparently in
exactly the same manner, the number of grains obtained may be vastly
different; indeed in some experiments scarcely any are produced. As
a rule the first solution extracted from any given preparation gives the
best results.
Chemical tests show that the grains are composed of protein, for
they respond strongly to all the protein tests such as the xanthoproteic,
Millon’s, etc. In each test the envelope responded just as strongly
as the crystal; it consists, therefore, of uncrystallized protein. With
other chemical reagents their behavior is that which is to be expected;
they are insoluble in water, alcohol, and sodium carbonate, soluble in
weak acids and alkalies and in salt solutions. No marked difference
could be observed between the solubility of the envelope and that of
the crystal. :
Under the action of putrefying bacteria, however, the behavior
of the envelope and crystal is occasionally different. In some cases
the crystal was dissolved out, leaving the ruptured envelope free; the
latter then became flattened out or turned back at the edges.
In the presence of a disinfectant to prevent putrefaction, the grains
usually remain unchanged indefinitely. Sometimes, however, the
envelope becomes more or less angular, the angles corresponding to
those of the crystal.
The proteids of other seeds were used in these experiments, but
in no case could artificial grains be obtained. Castor bean, hemp, an
lupine gave only crystals without envelopes.
In the case of Bertholletia, however, it seems evident that structures
resembling the aleurone grains formed through the activity of the pro
toplasm have been produced in the laboratory. This imitation consists
not only in reproducing what is probably the same chemical compound,
but also in reproducing the same morphological structure.
In conclusion I wish to acknowledge my indebtedness to Professor
W. J. V. OsterHovr, in whose course in plant physiology the original
observation was made, and with whose advice the subsequent work was
done.—W. P. Tuompson, Harvard U niversity.
CURRENT LITERAL ee
NOTES FOR STUDENTS
Metabolism of fungi.—Recently a number of papers on the metabolism
of fungi have appeared, which, although they represent various phases of the
subject, may be noted here in a collective review. Since PASTEUR’S discovery
racemic compounds, the study of the action of fungi on compounds having
asymetric carbon atoms has been of great interest. The work of the earlier
investigators, like that of LE BELL, LEuKowItTscH, SCHULZE and BossHarp,
and others, was concerned chiefly with the chemical aspects of the subject,
with the purpose of resolving racemic compounds into their optically active
components.
Taking up the subject more in its biological aspect, for the purpose of
determining whether any fungi are able to utilize both components of racemic
compounds to an equal extent, PRINGSHEIM' has investigated the action of
16 fungi and 2 bacteria on leucine and glutaminic acid, from which ScuuLzE
and BossHarp? had obtained d-leucine and l-glutaminic acid by the action
of Penicillium. PRINGSHEIM found that in all cases both of the components
of the amino-acids used were partly consumed by the organisms. In about
one-half of the experiments both components were consumed to an equal
€gtee, so that the recovered portions of the acids were optically inactive.
In the remaining instances one isomer was consumed to a greater extent than
the other, the naturally occurring component being the one consumed most
readily in all such cases.
RZOG and his students have taken up the study of the action of fungi
ates d-l-oxyacids and d-l-amino-acids in order to gain a knowledge of the process
mvolved in the utilization of one of the isomers of the inactive forms of these
acids. The experimentation was carried out both with living fungi and with
mycelia killed by various means. In the experiments with living material
the fungi were grown in flasks of suitable culture media until the carbon
dioxide production became constant. A definite quantity of the acid to be
tested was then introduced into the flasks and the subsequent carbon dioxide
Output determined. At the end of the experiment the residual acid was
_ *Princsuer, Hans, Studien iiber Spaltung racemischer Aminosiuren durch
Pilze. Zeitschr. Physiol. Chem. 65:96-109. 1910.
*Scnuize, E., und BossHarp, E., Untersuchungen iiber die Aminosdiuren
welche bei der Zersetzung der Eiweissstoffe durch Salzsiure und durch Barytwasser
entstehen. II. Zeitschr. Physiol. Chem. 10: 134-145. 1886.
339
340 BOTANICAL GAZETTE [OCTOBER
determined and its rotation measured. In the experiments with fungi killed
by acetone, methyl alcohol, or other means, the powdered fungus material
was added to flasks containing solutions of the acids. The carbon dioxide
products and residual acid were determined as before.
In the first experiments reported by HERzoc and Meter: it was found that
the addition of lactic, tartaric, malic, mandelic, and B-oxybutyric acids to
cultures of Penicillium glaucum, in which the carbon dioxide production had
become fairly constant, resulted in a great increase of the carbon dioxide
output. In every case the excess of carbon dioxide over the normal was much
greater than that calculated on the assumption that all of the acid used up
had been completely oxidized to carbon dioxide and water. Under the same
conditions glycollic, citric, pyrotartaric, and oxybutyric acids gave no increase
in the carbon dioxide production. The authors suggest that these experi-
ments indicate that the biological splitting of substances containing an asym-
metric carbon atom depends on a process of oxidation. Only the acids having
an asymmetric carbon atom were oxidized.
To test this hypothesis further, experiments were carried out with fungous
material killed with acetone and methyl alcohol and finely pulverized. Defi-
nite quantities of the material were added to flasks containing solutions of
lactic acid or sodium lactate, and also to control flasks containing distilled
water. It was found that the carbon dioxide production in the flasks con-
taining the acid or its salt was slightly greater than in the controls.
In a second paper! the method of experimentation with killed mycelia
is applied to the study of a number of other acids. The mycelia in these
experiments were immersed in liquid air, by which, it was assumed, the cells
were killed, although the spores were subsequently found to be alive. In these
experiments it was found that d-tartaric acid, /-tartaric acid, and d-/-tartaric
acid were oxidized, while mesotartaric acid, which is not separable into optically
active components, was left intact. The dextro-rotatory form was ox!
most rapidly. The optically active isomers of lactic acid showed scarcely
any difference in the rate of oxidation, while /-mandelic acid was ox!
more rapidly than its antipode. Glycollic acid, having no asymmetric carbon
atom, was not attacked. The authors conclude that the preferential oxidation
of one component of a racemic mixture, which has heretofore been regarded
as biological selections of food substances, is merely the result of differences
in the reaction velocities of the antipodes with the substances of the
organisms. :
In continuation of the foregoing work, HeRzoc and RipKe’ have studied _
3 Herzoc, R. O., und Meter, A., Ueber Oxydation durch Schimmelpilze. Zeitschr.
Physiol. Chem. 57:35~-42. 1908; also Meter, A., Dissertation under the same title.
Karlsruhe. 1909.
Ibid. §9:57-62. 1909.
‘ Herzoe, R. O., und Rieke, O., Ueber das Verhalten einger Pilze zu organischen
Saéuren. Ibid. 73: 284-289. 1911.
1912] CURRENT LITERATURE 341
the effects of Oidiwm lactis killed with acetone and ether on the lactic, succinic,
and mandelic acids. The results obtained do not conform with those obtained
mandelic and succinic acids the control flasks yielded greater amounts of
carbon dioxide. In an experiment in which the fungus was left in liquid air for
several hours, subsequent cultures showed that the cells had not all been killed.
A similar set of experiments carried out by HERz0G, RIPKE, and SALADIN®
with acetone preparations of M ycoderma cerevisiae showed that with acetic acid
and lactic acid the carbon dioxide production was less in the acid medium than
in distilled water, although a part of the acid in each case had disappeared. The
carbon dioxide output in experiments with the different isomeric modifications
of mandelic and tartaric acids was not determined, but the whole added quan-
tity of these acids could not be recovered. In some cases with mandelic acid
the total acid content of the controls at the end of the experiment was as great as
that in flasks to which acid had been added. The authors assume that the
autolytic production of acid by the killed fungus cells reaches a certain maxi-
m If that maximum has been attained by the addition of a foreign acid,
no Fests spontaneous acid formation occurs. Succinic acid depressed the
production of carbon dioxide, but there was no evidence that any of the acid
had disappeared. The general conclusion from this last set of experiments is
that the production of carbon dioxide by killed cells of Mycoderma is depresse
in acid media, although the quantity of acid is diminished. The disappearance
of the acid, therefore, cannot be explained as a process of oxidation, nor is the
process ere of met ee since the _ were nae In view of the compara-
tively small quanti through the action
of the killed fungus cells, the experiments would lave been more convincing
if the authors had reported control experiments — how much of the acids
could be immediately recovered from the mixtur
[In another paper by HERzoc and SALADIN? ae effect of leucine on the
carbon dioxide production of Penicillium is reported. The method of experi-
mentation was similar to that described above in the ae of Herzoc
and Meter, and the results were comparable to those obtained with oxyacids.
The addition of leucine was followed by an increased production of carbon
dioxide, which was greater than that calculated on the assumption that all the
available leucine had been oxidized to carbon dioxide and water.
The important series of researches of Enruicu® on the behavior of amino-
a
* Herzoe, R. O., RiPKE, O., und SALapIN, O. Ibid. 733 290-301. TOTI
’Herzoc, R. O., und Sataprn, O., Ueber das Verhalten einiger Pilze gegen
pals saeeae Ibid. 732 302-307. 1911
* For a general account of this one see Enruicu, F., Ueber die chemischen
Vorginge pflanzlichen Fovid-aibibdeiail und ihre Bedeutung fiir die Alkoholische
Garung und andere pflanzenphysiologische Processe. Landwirth. Jahrb. 38: 289-327.
1909.
342 BOTANICAL GAZETTE [OCTOBER
acids in alcoholic fermentation has greatly advanced our knowledge of the
origin of fusel-oils, which have usually been regarded as side-products of sugar
fermentation. These investigations have been extended by Exrticn and
Jacogson? to other fungi, to determine whether the decomposition of amino-
acids induced by them is similar to that brought about by the yeast cell.
The authors have studied the action, on amino-acids, of some 50 fungi, upon
which a complete report is promised. The behavior of the filamentous fungi
toward amino-acids differs greatly according to whether carbohydrates are
present or not. In the absence of carbohydrates the decomposition of amino-
acids is more extensive than that produced by yeasts, but in the presence of
carbohydrates the degree of decomposition differs with different fungi. In the
present paper the peculiar behavior of Oidiuwm lactis on amino-acids in the
presence of sugar is reported. The action of this fungus results in the replace-
ment of the amino-groups by hydroxyl, thereby yielding oxyacids correspond-
ing to the amino-acids according to the following general reaction:
R - CH(NH,)CO,H+H.O0=R - CH(OH)CO,H+NH;
The ammonia which is formed is used in protein synthesis by the fungus.
Here as with the yeast cell the amino-nitrogen (in the form of ammonia) enters
into the metabolism of the cell, while the rest of the molecule is excreted as a
product not capable of being further utilized. The end products in the two
cases are different, being in the case of the yeast cell an alcohol with one carbon
less than the amino-acid from which it was derived, while with Oidium lactis
an oxyacid corresponding to the amino-acid results. By the action of Oidium
lactis, l-tyrosin yielded d-paraoxyphenyl-lactic acid, d-/-phenylalanin yielded
d-phenyl-lactic acid, and /-tryptophan gave /-indol-lactic acid, all acids which
were heretofore not known in those modifications.
In this connection the authors point out that KoraKe” obtained from dogs
suffering from phosphorus poisoning the levorotatory form of oxyphenyl-
lactic acid, thus affording an example of the production by the plant and by
the animal cell, not of the same but of opposite stereoisomers from one and the
same substance. It should be stated, however, that KoTake himself regards it
as extremely improbable that his acid was produced from tyrosin, as he was
unable to isolate oxyphenyl-lactic acid as a result of feeding tyrosin itself. |
A better example of the production of isomeric antipodes from the same
racemic substance is afforded by the action of plant cells and of animal cells on
racemic phenylamino-acetic acid. NEUBAUER and WaRBuRG" obtained the
: 9 _* EqRtice, — _ JACOBSON, K. ia Ueber die Umwandlung von Amino-
sdu y Ber. Deutsch. Chem. Gesells. 44: 888-897-
nes
E, Y., Ueber /-Oxyphenylmilchsaure und ihr Vorkommen im Harn bei
Pronto Zeitschr. Physiol. Chem. 65: 397-401. 1910.
* NeuBaver, O., und Warsure, O., — eine i See mit Essigsdure in der
kiinstlich es Mutnens Leber. Ibid. 70: 1-9.
1912] CURRENT LITERATURE 343
. d-acetylphenylamino-acetic acid from this substance injected into the liver
of dogs, while NEUBAUER and FRoMHERz” obtained the l-acetylphenylamino-
acetic acid as a result of yeast fermentation of the same racemic compound.
intermediate chemical transformations by which d-amino-acids are
ae into alcohols with one carbon atom less in fermentation have been
investigated by NEUBAUER and FRoMHERz and described in the paper cited
above. The content of the paper is largely chemical. The conclusion is
reached that the amino-acids are not directly transformed into alcohols by
hydrolysis and subsequent splitting off of ammonia and carbon dioxide, as
represented by the general formula
R-CH-NH,—COOH+H,0=R - CH,0H+CO.+NH;
but that keto-acids are first formed, and these, by loss of carbon dioxide and
reduction, are changed into alcohols, the main steps of the process being
represented as follows
R—CHNH,—COOH+0=R—CO—COOH+NH;
R—CO~—COOH >R-CHO+CO
R—CHO+2H=R—CH,OH
This interpretation is the result of experiments in which it was shown (1) that’a
keto-acid (phenylglyoxylic acid) was formed by the fermentation of phenyl-
amino-acetic acid, and (2) that a keto-acid (p-oxyphenylpyrotartaric acid)
yielded the same alcohol by fermentation as the corresponding amino-acid
(tyrosin).5 A number of side reactions and secondary products occur in this
Process. The occurrence of the aldehyde is postulated. According to the
authors the decomposition of amino-acids by yeasts is hereby shown to follow
the same course as the decomposition of these acids in the animal body, except
that the postulated aldehyde which is reduced to alcohol by the yeast cell is
oxidized to the corresponding fatty acid which is further utilized in metabolism
by the animal cell.
The discovery by Exriicu™ of the production of fumaric acid from sugar
through the agency of Rhizopus nigricans is of great biological interest, not only
because it is the first instance of the occurrence of fumaric acid as a product of
metabolism of micro-organisms, but also because of its possible bearing on the
origin of unsaturated acids in higher plants. The acid was isolated by EHRLICH
from culture solutions, containing much sugar, upon which Rhizopus nigricans
was grown. The quantity of acid varies with the sugar content, but in old
cultures from which the sugar has disappeared the acid is again consumed.
” NevBaueR, O., und Fromnerz, K., Ueber den Abbau der Aminosauren bei
der Aptea Zeitschr. Physiol. Chem. '70: 326-350. 1911.
, Ferrx, Ueber die Vergirung des Tyrosins zu trieftates -ithyl-
— (Tyrosel) Bes, Deut tsch. Chem. Gesells. 44: 139-146. 1911
4———., Ueber die Bildung von Fumarsdure durch SRE Ber. Deutsch.
Chem, Gesells. 4423737-3742. ror.
344 BOTANICAL GAZETTE [OCTOBER
With glycerin, alcohol, or peptone as sources of carbon, no fumaric acid is
produced. e fact that fumaric acid here occurs as an intermediate
product in the metabolism of sugar suggests that unsaturated acids in
higher plants may result from carbohydrate metabolism. That a close
relation exists between the higher unsaturated acids and carbohydrates in
plant metabolism has been generally conceded by plant physiologists since
the work of MAQuENNE.
That many fungi and bacteria are able to utilize fats has been shown by
several investigators. A further contribution to the subject has been made by
forms of fungi obtained by exposing culture plates in the laboratory. The
the others, Aspergillus used 17-20 per cent, Cladosporium 14 pet
cent, and Penicillium 6-8 per cent. Attempts to grow Actinomucor on culture
solutions containing fat as the only source of carbon, in order to study the
mode of decomposition of the fat, were unsuccessful. The paper contains
detailed notes on the methods and precautions to be observed in making fat
determinations in work of this kind.
Another contribution to the subject of the utilization of fat by fungi has
been made by Roussy," who experimented with the following forms: Absidia
glauca, Circinella wmbellata, Mucor mucedo, Phycomyces mnitens, Rhizopus
nigricans, Sporodinia grandis, Morteirella candelabrum, Aspergillus flavus
Citromyces glaber, Penicillium luteum, Sterigmatocystis nigra, and S. por otrichase
yceum. All of these grew well on fats and oils of various kinds. To
determine if it was the fatty acid or the glycerine which was utilized, cultures
were made in Raulins solution in combination with oleic, palmitic, or stearic
acid or glycerine. It was found that the fungi thrived well on the fatty acids,
but only Aspergillus and Penicillium grew on glycerin solutions
ICHEL, studying the effects of acetic acid and its salts on a torn of Peni-
cillium, has rediscovered the fact that the toxicity of that acid is mainly due
to the action of the undissociated molecule. He finds that acetic acid is poison-
ous in much lower concentrations than those at which the strong mineral acids
are toxic, but, owing to its slight dissociation, its toxicity cannot be attribut
to the hydrogenion. At the same time, the salts of acetic acid, which are highly
dissociated, are not poisonous, hence the acetate ion is not poisonous
toxicity of acetic acid, therefore, must be attributed to the molecule as a whole.
*sOuta, Kousut, Ueber die fettzehrenden Wirkungen der Schimmelpilze nebst
dem Apert des Organfettes gegen Faulniss. Biochem. Zeitschr. 31:177-194- 197?.
oussY, = Sur la vie des Champignons dans les acides gras. Compt. Rend.
153: foun IQIt
1912] CURRENT LITERATURE 345
The same conclusion reached by CLARK” by similar experimentation and
reasoning many years ago seems to have escaped his notice.
REICHEL” further points out that the addition of mineral acids to solutions
containing acetates produces the same effect as the addition of acetic acid, since
the acetic acid is replaced in its salts by the stronger acids and undissociated
acid is formed in the solution as a result of the establishment of a new equi-
librium. In solutions whose acidity is not great enough to inhibit growth
entirely, the author finds a certain regulatory depression of the acidity by the
gus until more favorable concentrations are attained. This phase of the
subject seems to demand further investigation to determine whether such
Purposeful regulation really exists. Under certain conditions, at any rate,
depending upon the substances available in the medium, either acid or alkali
will accumulate in culture solutions through the action of fungi to such a degree
as to inhibit growth entirely.»
Borkorny” reports a number of miscellaneous experiments and observa-
tions indicating that methyl alcohol can be used as a source of carbon by some
fungi and bacteria. A yeast not capable of fermenting cane sugar or glucose
infusoria were present. Apparently no precautions were taken to avoid con-
tamination, so that it is possible that carbon compounds were introduced in
the form if dust particles.
Sarro** reports the formation of lactic acid by Rhizopus chinensis, thus
confirming the observations of EIJKMAN and of CurzAszcz, who reported the
Production of lactic acid by Rhizopus Rouxii. These observations had been
oubted because other instances of the production of lactic acid by filamentous
fungi are not known. Sarro identified his acid by means of the zinc and the
calcium salts and by the reaction of UFFELMAN.
Gouri finds that Rhizopus Rouxii produces in cultures up to 4 grams
Perea te
7 CrarK, J. F., On the toxic effect of deleterious agents on the germination and
development of evbidas filamentous fungi. Bor. Gaz. 28: 289-327; 378-404. 1899.
** REICHEL, J., Ueber das Verhalten von Pesan gegeniiber der Essigséiure
und ihren Sakzen. Biochem. Zeitschr. 30: 152-159. °.
” HASSELBRING, H., The carbon assimilation of Piucates Bor. Gaz. 45:176—
193. Spy 08.
RKORNY, TH., Beobachtungen iiber Pilze, welche Senne Nee als C-Quelle
verwenden kénnen. Centralbl. Bkt. II. 29:1
™ Sar K., Ein Beispiel von = RO durch Schimmelpilze.
Centralbl. Bake. I. 29: 289-290. I
* Gouptt, R., Recherches sur VAmylomyces Rouxii. Compt. Rend. 153:1172-
TI74. 191.
346 BOTANICAL GAZETTE [OCTOBER
per liter of succinic acid mixed with some acetic and some butyric acid. Con-
trary to the statements of some workers, oxalic and lactic acids are not
produced. He believes that the succinic acid is formed from sugar and not
from any amino-acid.—H. HassELBRING.
Current taxonomic literature—G. E. Osternout (Muhlenbergia
8:44, 45. 1912) characterizes a new Cogswellia (C. concinna) and a new variety
of Gnaphalium (G. vagal ee var. glandulosum) from Colorado.—O. PAULSEN
(Arb. Bot. Have Kb. 65. 303-318. 1011) under the title “Marine
plankton from the East- cdiaci Sea” records the Peridiniales found on the
Danish Expedition to Greenland in 1906-1908 and describes a new species of
Peridinium (P. varicans), also a new species doubtfully referred to A podinium.
—W. H. Rankin (Phytopathology 2: 28-31. pl. 3. 1912) describes and illus-
trates a new fungus (Sclerotinia Panacis) which is said to be the cause of a
root-rot of ginseng; it was found near Apulia, N.Y.—A. B. RENDLE, E. G
BAKER, S. goa = A. ets oar. Linn. Soc. Bot. 40:1-245. pls. I-7.
1911) h entitled “A contribution to our knowl-
edge of the Flora f Gétaland. y The paper includes a general descriptive
account of the country concerned, records about 1000 species of which approxi-
mately 180 are new to science. The plants were collected by Mr. C. F. M.
SWYNNERTON and the types are deposited in the herbarium of the British
Museum.—R. A. RotFe (Bot. Mag. ¢. 8417. 1912) describes and illustrates a
new species of Stanhopea (S. peruviana) from Peru, and (Kew Bull. 131-135.
1912) has published several new species of orchids including 4 from Panama
and South America.—E. Rosenstock (Rep. Sp. Nov. 10: 274-280. 1912) under
the title “Filices costaricenses” has published 11 new species of ferns. —P. A.
RypBerG (Torreya 12:1-11. 1912) in continuation of studies of the plants
collected on the Peary arctic expeditions gives a list of the plants secured by
Drs. WoLF and GoopsELt; the article includes a new species of Conioselinum
(C. pumilum Rose) from Bdhratioc: The same author (Bull. Torr. Bot. Club
39:99-111. 1912) under “Studies on the Rocky Mountain flora XXVI”
describes a new species in Deschampsia and one in Anticlea. Two new generic
names are proposed, namely Hesperochloa, based on Poa (?) Kingit bees "
and Dipterostemon, based on Brodiaea capitata Benth—C. S. SARGENT
Mo. Bot. Gard. 22:67-83. 1911) under the heading ‘Crataegus in Missouri
Il” has described 14 new species.—A. K. ScHINDLER (Rep. Sp. Nov. 107493;
404. 1912) has published a new genus (Kummerowia) based on pangenee
new genera belonging to the Amarantaceae: Centemopsis, Nelsia, N eocentemd,
and Lopriorea.—R. SCHLECTER (Rep. Sp. Nov. 10: 248-254, 291-290, 352~
363, 385-397, 445-461. 1911-1912) under the title “Orchidaceae novae et
criticae” has published about 70 new species of orchids from Central and
1912] CURRENT LITERATURE 347
South America. One new genus (Neokoehleria) is included from Peru.—The
same author (Orchis 6:6-10. pl. r. 1912)-has published new species of orchids,
2 of which are from Colombia.—F. J. Seaver (Mycologia 4:45-48. pl. 57. 101 .
gives an account of the genus Lamprospora and adds 2 new species.—C.
SMITH (Muhlenbergia 7: 136-138. 1912) records a new variety of violet wa.
Beckwithit var. cachensis) from northern Utah.—O. Stapr (Hooker’s Ic. IV,
10: ¢. 2947. 1911) describes and illustrates a new genus (Teonongia) of the
Moraceae from Tonkin; the same author (ibid. tt. 2949, 2950) describes and
illustrates two new genera (Lintonia and Dignathia) of the Gramineae from
British East Africa —P. C. STANDLEY (Proc. Biol. Soc. Wash. 24: 243-250.
1911) presents a synopsis of the American species of Fagonia, recognizing
12 “St : of which are new to science. The same author (Smith. Misc. Coll.
56: I-3. 1912) has described 3 new species of flowering plants
from asta, and (ibid. NO. 34. 1-3. pl. 1) describes and illustrates a new
PHANI
Sv. Vet. Akad. Handl. 46: no. 9. I-92. 1911) presents the results of an
investigation of the Hepaticae collected on the Swedish expedition to Pata-
gonia and Tierra del Fuego in 1907-1909; about 145 species are described
as new to science. The types are deposited in the herbarium of the Botanical
Museum at Upsala. The same author (Sp. Hep. 4:641-736. 1911) continues
his treatment of the Hepaticae and includes several new species from America
belonging mainly to Frullania and Archilejeunea.—C. TOoRREND (Broteria
Ser. Bot. 10:29-49. 1912) under the title of “Deuxiéme contribution pour
étude des champignons de Vile de Madére’’ describes several species new to
Science and proposes a new genus (Vermiculariopsis) of the Sphaeropsidaceae.
—W. TRELEASE (Rep. Mo. Bot. Gard. 22:37-65. pls. 18-72. 1911) presents an
illustrated account of the agaves of Lower California with a synopsis of the
25 reorganized species of which 17 are new to science; and (ibid. 85-97. pls.
73-99) gives a “Revision of the agaves of the group APPLANATAE,” to which
group Io species are referred, 5 being hitherto undescribed; and (ibid. 99, 100.
bls. 00-103) characterizes a new variety of Agave (A. angustifolia var. Sar-
gentit) based on plants in cultivation at the Missouri Botanical Garden; and
(ibid. 101-103. pls. 104-108) records 2 new species of Yucca from Texas and
adjacent Mexico.—W. WanceErIn (Rep. Sp. Nov. 10:273. 1912) has published
& new species of Mastixia (M. philippinensis) from the island of Luzon, P.I.—
E. J. Wetsrorp (Ann. Botany 26: 239-242. 1912) gives an account of an alga
found in an aquarium associated with Azolla caroliniana which was imported
from North Carolina. The author has given the alga the name of Trichodiscus
elegans.—H. F. WERNHAM (Journ. Bot. 492317, 318. 1911) has published a new
genus oe of the Rubiaceae from Demerara.—Different authors
ew Bull. 35-44. 1912) have published several new species of flowering
Plants including 2 new species of Columnea from Guatemala and Venezuela,
and a new Zschokkea from Peru; and (ibid. go—107) under the title ‘‘ Diagnoses
348 BOTANICAL GAZETTE [OCTOBER
africanae pata several new species are described, and the following new
genera are proposed: Isoberlinia and Paradaniellia of the Leguminosae, and
Klaineanthus Hie Hamilcoa of the Euphorbiaceae.—J. M. GREENMAN.
Recent work among Filicales.—Davis?} has investigated the struc-
ture of Peranema and Diacalpe, Asiatic genera of ferns whose relationships have
been somewhat doubtful. Both genera are polystelic; and while in Peranema
the short-stalked sorus is a mixed one, with a receptacle of the Gradatae type
and traces of a basipetal succession of sporangia, in Diacalpe the mixed sorus
shows no traces of basipetal succession. Moreover, in Peranema the annulus
is slightly oblique, while in Diacalpe it “‘is vertical in insertion, but slightly
twisted in its course across the sporangial head.” Both show relationships to
the Aspidieae. The conclusion is suggested that the Aspidium forms have
come from a Gradatae ancestry, and “that Peranema and oes are relatively
early members of a phyletic drift to the Polypodiaceae.’
Bower” has used a andy of Alsophila (Lophosoria) pruinata as the basis
for a discussion of an i ophosoria is shown to be a
more primitive type than the true species rol Alsophila and worthy of es
separation from that genus. The phyletic relations with Struthiopteris, Onoc
Costopterss, Acrophorus, Peranema, Diacalpe, Woodsia, and Hypoderris axe
“progressions” announced: (1) the frequent dichoto-
mous branching in Gesieccess becomes rarer in the higher types, and the
creeping axis of the earlier forms becomes ascending or erect in some 0 the
later ones”; (2) “the peculiarities of the original gleicheniaceous type of leaf
are shown in reminiscent details in the Cyatheaceae, but lost elsewhere”;
(3) progression from primitive hairs to scales; (4) progression from the proto-
stele of § Marrensta of Gleichenia to the eclencatele of G. pectinata and Lopho-
Soria, and the polystele of all other members of the series; (5) progression from
the Simplices type of sorus (Gleichenia and Lophosoria) to the Gradatae type
in Cyatheaceae, and finally to the Mixtae type in Hypoderris, Peranema, an
Diacalpe, “a condition leading probably to that of the Aspidieae”’; (6) pro-
gression from a larger spore-output and an oblique annulus to a smaller output
and a vertical annulus; (7) progression from a larger sperm-output to 4
smaller one.
is series is believed by Bower to constitute a true phylum, a phylum
quite distinct from that of the ferns with originally marginal sori. The pro rob-
*s Davis, R. C,, The structure and affinities of Peranema and Diacalpe. An?
Botany eS pls. 28, 29. 1912
74 BowER, F. O., Studies in the sbi e of the Filicales. Il. Lophosoria, and
its iether Hs the Cra theatiess and other ferns. Ann. Botany 26:269-323- ie
30-36. 1912.
-
1912] CURRENT LITERATURE 349
able phyletic sequence of families, SAG is as follows: ‘“ Gleicheniaceae,
Cyatheaceae (with minor groups, e.g., Woodsieae, etc.), Aspidieae.”
Miss Humes has eer the sieve tubes of Pteridium aquilinum,
and compared them with those of Lygodium dichotomum and Marsilia quadri-
folia. The xylem has long received intensive study on account of its service
in conclusions concerning phylogeny; but there are symptoms that the phloem
is now beginning to come into its own. The stock contrasts between the sieve
tubes of pteridophytes and spermatophytes are now beginning to break down
and Miss Hume has contributed her share to this process. Not only does
callus appear, as Russow showed, but the author shows that the pores are not
closed. “The outstanding differences are in shape and contents; the sieve
tubes of vascular cryptogams are larger and thicker walled and contain refrin-
gent granules.” The larger size and thicker walls are thought to be associated
with the fact that the sieve tubes of pteridophytes (on account of the absence
of secondary thickening) have to function for a long time, in some cases for as
much as 20 years, while in some dicotyledons and gymnosperms they are
renewed each year. The time is at hand when the sieve tubes can be linked
up in phyletic sequences as the xylem elements have been.
THomas* has discovered in the Jurassic of Yorkshire sporangia of Coniop-
leris hymenophylloides Brongn. and Todites Williamsoni Brongn., which support
the view that the former species is closely related to the modern Cyatheaceae,
and which furnish for the latter species additional points of resemblance to the
modern Todea. Fertile material of Cladophlebis lobifolia Phill. was also secured, .
which justifies its removal from the fo orm-genus and its provisional placing in a ©
new genus Eboracia, related in sori and aie to Coniopteris, but very distinct
in the form of the fertile fronds. 9
American cecidology. —All students of the biological sciences will
be interested in the i 1 attention which cecidology is receiving in America,
and also in the fact that it is being studied by both entomologists and botanists.
FELT presents four papers. In the first” he gives a very complete list of
Plants on which the cecidia of our American gall midges are known to occur
and the names of the gall-makers. Our knowledge of this group of gall-makers
is very indefinite, and therefore the very brief one-line descriptions may appear
"piece to many who are unfamiliar with the subject. However, the
t will prove of very great value to the student of plant pathology and
cecidology. In a second paper* Fett describes 17 new species of gall midges,
ns
__ *’ Hume, E. M. Marcaret, The history of the sieve tubes of Sola —
with some notes on Marsilia quadrifolia and Lygodium dichotomum. . Botany
26: 573~587, pa 54, 55. 10T2.
** Tuomas, H. Hamsuaw, se the spores of some Jurassic ferns. Proc. Cambridge
Phil. ae 16:3 388 pl. 3. 19
coe he Hosts and ‘aie of American midges. Jour. Econ. Entomology
seast—a7.
$——___ one species of gall midges. Ibid. 4:476-484. IgIt.
350 ' BOTANICAL GAZETTE [ocroBER
but many of them are not true gall-makers while others produce very small and
insignificant galls. In a third paper” the same author describes three new
species of dipterous gall-makers, and in the fourth3* he describes four new
species of gall midges from St. Vincent, West Indies. The development and
structural characters of all these galls remains to be worked out by the botanist.
EUTENMULLER® has given us another most excellent paper on the North
erican galls. This last paper is on the genus Dryophanta, and contains
excellent descriptions of both galls and insects of the 39 known species, with
complete synonomy and bibliography. Most of the galls are figured, and all
of them occur on oaks, but in a few cases the specific name of the host is not
known. The 32 species for which the hosts are given are found on 24 species
of oak. Qwercus rubra leads with 7 species, Q. alba has 5, Q. coccinea has 4,
Q. undulata, Q. velutina, and Q. nana have 3 each, Q. arizonica, Q. marylandica,
Q. prinoides, Q. palustris, and Q. laurifolia have 2 each. Dryophanta palustris
is found upon 7 different hosts, D. Janata on 5, D. notha on 3, 5 other species
on 2 each, and 24 species on 1 each.
The same author? also describes and figures two new species of H olcaspis
galls from Mexico. These papers will be absolutely necessary for students
who wish to make botanical studies of cecidia.
One of the most interesting and important contributions to American
cecidology is by Erwin F. Smitu,33 who has continued his studies on crown
gall of plants, and presents some interesting comparisons with the cancer of
human beings. The similarity between plant and animal malformations has
_ attracted the attention of many observers, who have looked upon the study
of plant galls as a fruitful field of investigation, but unfortunately very few
have gone into it far enough to see the real possibilities. SmrrH’s confidence
in this line of work is expressed as follows: “I believe we have in these pat-
ticular plant overgrowths a key to unlock the whole cancer situation. In
consideration of these discoveries many closed doors in cancer research must
now be opened, and studies on the etiology of the disease must be done over
with a view to finding a parasite within the cancer cell, and separating it
therefrom by an improved technic of isolation.” In answer to his critics he
claims that the crown gall is not the same as a granulomata of the animal. He
also shows that the tendency of the human cancer to form secondary growths
by means of strands of tissue is similar to the formation of secondary growth
* Feit, E. P., Three new gall midges. Jour. N.Y. Entom. Soc. 19?190-193-
IQIT. :
30
, New West Indian gall midges. Entomol. News 23:173-175- 191?
#* BEUTENMULLER, WiLtiAM, The North American species of Dryophanta and
their galls. Amer. Mus. Nat. Hist. 30: 343-369. I9II.
# , Two new species of Holcaspis from Mexico. Psyche 18:86, 87- 18
33 SmirH, Erwin F., On some resemblances of crown gall to human cancet-
Science N.S. 3§:161-172. 1912.
1912] CURRENT LITERATURE 351
of the crown gall, and believes that “we have in the crown gall a striking
analogy to what occurs in malignant animal tumors.”” He does not claim that
the animal cancer and crown gall are due to the same organism. The latter
part of the paper is devoted to physiological characters of the organisms and
presents some suggestions which will be of importance to the plant physi-
ologist who has the courage to attempt to explain the formation of plant
cecidia as a result of irritation by parasitic fungi and insects. Met T. Cook.
Inheritance in fiax.—Tammes* has studied a number of characters
in crosses between two varieties of the common flax (Linum usitatissimum)
and between these and L. crepitans and L. angustifolium. She has dealt
coastal with the length of seeds, length and breadth of petals, color
the flowers, degree of opening of the mature capsules, and the hairiness
of the dissepiments of the capsules. Hairiness of the capsules and the lightest
blue color of the flowers are each determined by a single Mendelian gene, but
all the other characters are obviously more complex. The author believes
that all of these characters are likewise determined by genes which segregate
normally in the F., though they cannot be followed individually because
Several genes affect the same characteristic and act together in such a way that
the grade of development of the character depends approximately on the
number of these genes present. This results in a continuous series of grada-
tions which are superficially indistinguishable from fluctuations, but which
differ by being inheritable. Several evidences for the correctness of this
interpretation are reported: The F, is in each case intermediate between the
parents and no more variable than they ; in the F, the variability is considerably
increased, and the curves stretch out toward those of either parent, but fre-
quently fail to reach them owing to the small size of the families investigated;
when F, families are grown from the extreme variants of the F., a still closer
approach to one or the other P, results, apparent identity with the parental
type being attained in several cases. From the proportion of F, and F;
families which approached in any given cioerehaitatte the condition of the
P, generation, Miss TAMMEs estimates the number of genes probably involved
in differentiating the two parental types in each cross with respect to the
Several characteristics studied. She concludes that in length of seeds not less
than four differentiating genes were involved in every cross made, in some
Crosses certainly a still larger number. In width of petals the simplest cross
must have had differences between the parents in 3 or 4 genes, and the other
Crosses a considerably - higher number. In flower-color different intensities
of blue were apparently dependent on three genes. Between capsules which
remain closed at maturity and those that spring wide open, 3 or 4 genes are
rite Later generations will be needed fully to test these conclusions.—
EO, H. S
Tames, T., Das Verhalten fluktuierend variierender Merkmale bei der Bas-
tardierung. Recueil Trav. Bot. Neerlandais 8:201-288. pls. 3-5. 1911
352 : BOTANICAL GAZETTE [OCTOBER
Beach vegetation.—A detailed ecological study of the beach vegeta-
tion of that portion of the shores of Lake Michigan which extends from Wauke-
gan, Illinois, to Kenosha, Wisconsin, has recently been made by GATES.
Unfortunately it contains little in the way of quantitative data upon the
various factors involved, but as a record of the vegetation of this region it
is an admirable and valuable contribution.
The lack of any definitely fixed conception of what constitutes the unit
of vegetation known as a “plant association” is shown not only by the author’s
review of the literature upon the subject, but also by his subdivision of the
vegetation of the very limited area under investigation into more than fifty
different associations. Such a multiplication of associations indicates a_
danger of making the segregation ap a floristic depres than an aero ene
and also points to the need of some w
and yet, even with the most conservative treatment, it is to be expected that
a region such as this, representing as it does the meeting place of the northern
conifer, the eastern deciduous, and the prairie plant provinces, would present
an unusual number of vegetational types. The genetic relationship of these
various associations is clearly indicated and exhaustive lists of species are
given.—Gero. D. Futter.
The black oaks.—At the meeting of the American Philosophical
Society (Philadelphia) on April 19, 1912, Dr. TRELEASE discussed the classi-
fication of the black oaks. The abstract of his paper is as follows: Attention
to bud and fruit characters has led to a classification of the black oaks quite
different from their usual ling to leaf-form, and five groups of
species are recognized, three of the Eastern sates: one of the Southwest, a
one of the Pacific states. The eastern groups are the black oaks (black jack,
turkey oak, Spanish oak, and quercitron), scarlet oaks (scarlet oak, gray oak,
Hill’s oak, red oak, Texas red oak, and bear oak), and swamp oaks, these of
two sets, the water oaks (water oak, pin oak, and Stone Mountain oak) and
willow oaks (shingle oak, willow oak, laurel oak, running oak, cinnamon oak,
and myrtle oak). The iit lweatecn olive oaks (Emory’s oak and the white-
leaf oak) and the Californian holly oaks (evergreen oak, Highland oak, and
Kellogg’s oak) are less related to one another and to the eastern black o
than these are to one another, and appear to have originated independently
of them.
Nuclear phenomena in the Uredineae.—Wetr* has published 4
brief summary of the outstanding features of the Uredineae, which will be of
service to those who wish a condensed outline of the nuclear conditions in the
various stages of the life history of rusts.—J. M
*s GATES, FRANK C., The vegetation of the beach area in northenee pie and
southeastern ‘Wisconsin. Illinois State Lab. Nat. Hist. 9: 255-272. pls. 37-56. 191%
36 WEIR, JAmes R. ,A at review of the nee! PSRABET: and cytological
cheese of the Uredineae, notes on a ton: in oe promycelium of Coleo-
ie Pulsatillae (Str.). New Phytol. rz: Es 8h
Vol. LIV No. 5
THE
BoTANICAL GAZETTE
November 1912
Editor: JOHN M. COULTER
CONTENTS
The Development of Blastocladia strangulata, n. sp.
J. T. Barrett
The Orchid Embryo Sac Lester W. Sharp
Growth Studies in Forest Trees Harry P. Brown
Contributions from the Rocky Mountain Herbarium. XII
Aven Neilson
Two Species of Bowenia Charles J. Chamberlain
Briefer Articles
A New Species of Andropogon A. S. Hitchcock
Evaporation and the Stratification of Vegetation George D. Fuller -
Current Literature
The University of Chicago Press
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THE MARUZEN-KABUSHIKI-KAISHA, Tokyo, Osaka, Kyoto
Che Botanical Gazette
A Montbly, Journal Embracing all Departments of Botanical Science
Edited by JoHN M. CouLrer, with, the assistance of be members of the botanical staff of the
Tsity of
Issued November 13, 1912
Vol. LIV ~—-« CONTENTS FOR NOVEMBER 1912 -—s«No. 5.
THE DEVELOPMENT OF BLASTOCLADIA STRANGULATA, N. SP. (witH PLATES XVIII-
Me Jie Barret. - - % - Z J . ‘ Fi th “ % \ 4
THE ORCHID EMBRYO SAC (wit PLATES XXI-Xxill). Lester W. Sharp = - mae ee ae
ac STUDIES IN FOREST TREES..- 1. pEIRNS RIGIDA 3 MILL ere PLATES, XXIV
xxv). Harry P. Brown 386
comreericad FROM THE ROCKY MOUNTAIN HERBARIUM. .XIl. Aven Nelson 404
Two SPECIES OF BOWENIA. CONTRI IBUTIONS FROM THE Hurt BOTANICAL LABORATORY 162
(WITH FOUR FIGURES). Charles J Chamberlai id
BRIEFER ARTICLES
A New Species oF Aeon: ASS. Hitthcock eS “are
SE vaccu beam au axe seg iaiaiciee OF VecEration —_ ONE moves) as D.
Pulle " S x » 2 . -
CURRENT LITERATURE
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+ NOTES FOR STUDENTS gle ieee Sh, Adina ag ais miei ast La eg pete Halle kOe eee Ne
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VOLUME LIV NUMBER 5°
ey &
DOTANICAL “GAZETTE
NOVEMBER 1912
THE DEVELOPMENT OF BLASTOCLADIA STRANGU-
rr
J. -f. BARRETT
(WITH PLATES XVIII-XxX)
The genus Blastocladia was founded and incompletely described
in 1876 by Rernscu (6) on the single species B. Pringsheimii,
which for twenty years remained its sole representative. In 1896
THAXTER (9) rediscovered and made a careful study of the plant, —
which up to that time, apparently, had not been again observed.
His studies cleared up several doubtful or unknown points in con-
nection with its life-history and development, and led to the descrip-
tion of a new species, B. ramosa. Up to the present, so far as the
writer is aware, no other species has been added to the genus.
Aside from its peculiar characters, the genus is of particular inter-
est because of its doubtful systematic position. Because of the
resemblance of the resting spores to the deciduous conidia of certain
Pythium species, THAxTER (9) placed the genus provisionally
among the Pythiaceae. FiscHer (1) considers it with the genera
which are doubtful or to be excluded from the Saprolegniaceae,
while ScHr6TER (7) includes it with the Leptomitaceae.
The species described in this paper fixes with considerable
certainty, the writer believes, the true systematic position of the
genus and is therefore described in detail.
This study was undertaken in the Botanical Laboratory of
Cornell University under the supervision of Professor GrorcE F.
*Contribution from the Department of Botany, Cornell University. No. 140.
353
354 BOTANICAL GAZETTE [NOVEMBER
ATKINSON, to whom I wish to express my thanks for his advice
and kindly criticisms.
Material and methods
A single plant of this species was discovered growing on an
aphid which had accidentally fallen into one of several water cul-
tures prepared for the purpose of entrapping various Phycomycetes.
The specific culture referred to was made from soil and decaying
vegetation taken from the bottom of a small almost dry inland
pond in the vicinity of Ithaca. When first observed the plant bore
large numbers of resting sporangia, whose arrangement and bright
orange color gave it a very beautiful appearance. After washing
through several changes of sterile water, the plant was placed in a
solid watch glass for further observation. On examination the
following day it was found that a number of zoosporangia had
developed, a few of which had already discharged the characteristic
zoospores first described by THAXTER (9) for B. Pringsheimit.
Cultures were immediately started with aphids and other
animal tissue, from which an abundance of material in all stages of
development was secured. After making several unsuccessful
attempts, a pure culture of the organism was obtained in the follow-
ing manner: A few nearly mature zoosporangia were cut from a
plant, carefully washed until practically free from contamination,
and allowed to discharge their zoospores in sterile water. By
means of a platinum loop the water containing the zoospores was
spread over the surface of newly prepared slants of sweet corn agar.
In a few days the small plants appeared as more or less isolated
refractive specks on the surface of the agar, and were easily lifted
out with a sterile needle and transferred to new tubes.
Material for sectioning was obtained in various stages of
development from both water and agar cultures. It was soon found
that the latter yielded just as good and more easily handled material
than the former and it was therefore more frequently used. To
secure the best results with the latter method, plants bearing nearly
mature zoosporangia were transferred to the middle of a poured
plate of either potato or sweet corn agar, preferably the latter, n 4
few drops of sterile water. After a few hours to one day large
numbers of zoospores will have been discharged and can easily be
1912] BARRETT—BLASTOCLADIA 355
spread over the plate by rocking the same or by the use of a sterile
platinum loop. Thus distributed, the zoospores soon germinate and
produce large numbers of usually simple plants bearing the repro-
ductive organs. They commonly lie sufficiently close so that most
of the agar may be cut out and fixed for microscopic study.
Three different killing solutions were used, which gave various
results. These were medium chrom-acetic acid, Flemming’s weak
solution, and Gilson’s fixer. After dehydration in the grades of
alcohol or by evaporating down from to per cent glycerine, the
material was cleared in cedar oil and imbedded in paraffin. Sec-
tions were cut 2-5 » thick and stained on the slide.
The stains used were Flemming’s triple stain with the orange G
dissolved in clove oil, Heidenhain’s iron-alum hematoxylin, and
Gram’s stain. The triple stain following Flemming’s weak solu-
tion gave the best material for the study of the walls of the resting
sporangia, papillae of dehiscence, and for fragmentation of the
protoplasm to form zoospores; while Heidenhain’s hematoxylin,
when preceded by medium chrom-acetic acid, gave much the best
material for the study of the protoplasm and nuclei. Gram’s stain
Proved very good as a nuclear stain.
Description of the plant
The plant consists of a basal cell or cylinder whose lower extrem-
ity is attached to the substratum by a system of rhizoids, and sup-
ports above a dichotomously or umbellately branched system whose
final branchlets terminate in one or more reproductive bodies
(figs. 12, 58). At the points of origin of the branches, and occa-
sionally elsewhete, there are more or less well marked constrictions
of the mycelium. This character at once suggests a relationship to
the members of the Leptomitaceae. The constrictions, however,
are more abrupt and usually of less depth than those of that
family. They mark off the plant into definite segments which are
fairly constant in diameter throughout, although they occasionally
have a tendency to enlarge slightly at one or both ends. This is
€specially noticeable in those branches which give rise to more
than two branchlets. In this they resemble somewhat the branch-
lets of Rhipidium americanum Thaxter (10).
356 BOTANICAL GAZETTE [NOVEMBER
At the constricted points one finds pseudo-septa in various
stages of development. These peculiar structures are unlike any-
thing in the way of septa that I have seen described. In the older
parts of the plant they reach their most perfect development, and
then only incompletely separate the protoplasm of the adjacent
segments. In a single well developed plant of some age, one may
find the pseudo-septa in all stages of formation. They are first
seen as separate processes or thickenings protruding inwardly from
the wall at the constrictions. These processes increase in length,
probably by accretion, until on meeting at the center of the cell, a
fusion takes place and a definite central plate results.
Fig. 18, a-d, represents different stages of development of a
septum, while figs. 19, 20, and 21 represent sections through such a
stage as that shown in fig. 18, a. In fig. 19 the section is through one
arm and the central plate, fig. 20 through two opposite radial arms
and the central plate, while fig. 21 shows a section through the
central plate alone. These pseudo-septa are much more highly
differentiated than the “‘cellulin” rings which are present in Gona-
podya and other Leptomitaceae. They permit a free interchange
of the protoplasm, and only under conditions of injury to the hypha
do they entirely close the lumen. Both the mycelial walls and the
pseudo-septa fail to give any definite reaction for cellulose. After
treatment with iodine and sulphuric acid, very rarely a slight trace
of blue color is seen in the mycelial walls. The pseudo-septa
become much swollen and take on a deep orange color, resembling
in this respect the reaction secured by PrincsHEmm (5) for the
*cellulin granules.” ,
In young actively growing plants the protoplasm is muc
vacuolated, granular, and contains, distributed throughout it,
prominent nuclei containing deeply staining bodies (figs. 28, 32):
Aside from the nuclei, there occur other deeply staining bodies
which are more or less regular in form and of various sizes. They
are very probably similar to those described by Remyscu (6) 4S
independent, endogenously produced cells, which he was inclined
to believe were the origin of the reproductive organs (see figs. a
28, 32). THAXTER (9) observed these same bodies in B. Prims*
heimii, and saw no reason for assuming that they were other than
1912] BARRETT—BLASTOCLADIA 357
masses of fatty protoplasm. Their true nature has not been deter-
mined, but, as will be shown later, they have at least one definite
function in connection with zoospore formation. They are always
present in more or less abundance, their extent of occurrence de-
pending, to a degree at least, on growth conditions of the plant.
In old plants, especially when the production of reproductive
bodies has ceased, large groups of such bodies may be seen
collected near the pseudo-septa, and frequently elsewhere in the
mycelium.
Bodies somewhat similar in appearance are known to occur in
the hyphae of members of the Saprolegniaceae. PRINGsHEIM (5)
describes these at length and records a series of microchemical tests
to determine their nature. According to his conclusions they are
neither a proteid nor a carbohydrate substance, but rather waste
products of metabolism.
Under favorable conditions of growth, a branchlet when ter-
minated by a reproductive body may continue its growth by the
production of a sub-branch (fig. 32). This sub-branch may be
likewise terminated, sooner or later, and continued growth repeated
as before. The length and rapidity of growth of these sub-branches
determines whether the reproductive bodies shall occur at intervals
or in a more or less compact head or group (figs. 6, 7, 12). This
type of sympodial branching occurs in depauperate specimens of
Rhipidium americanum (THaxTER 10). It has also been noted
for A podachlya.
Under the best normal conditions for growth, the ne of
zoosporangia precedes that of resting sporangia. In pure cultures
this order is easily reversed by properly manipulating external
conditions. In a frequently refreshed culture, zoosporangia alone
are at first produced, while on the other hand plants in a culture
started and maintained in a small amount of water usually give
_ Tise to resting sporangia only.
The extent to which branching may proceed before the produc-
tion of reproductive organs varies greatly. This may continue
until a well formed almost hemispherical tuft is produced, or on
the other hand zoosporangia may develop soon after the germi-
nation of the zoospore on the terminal end of the more or less
358 BOTANICAL GAZETTE [NOVEMBER
elongated basal cell. This condition occurs particularly on young
plants started on agar and subsequently transferred to water. If
sufficient moisture is present the same thing may take place directly
on the agar (figs. 4, 5). Zoosporangia may be produced singly or
in chains (fig. 59).
The growth of the plant is rapid when the best external condi-
tions are offered. Observations made relative to this point showed
that in one case hyphae which were just emerging from the body
of an aphid at 10:30 A.m. had produced at 5:30 P.M. of the same day
mature zoosporangia, some of which were discharging zoospores. —
The size of individual plants varies greatly with the purity of the
cultures and the nature and amount of nutrient material at hand.
Development of zoosporangia
The zoosporangia are broadly oval to almost spherical, rarely
elliptical, smooth, hyaline, and fairly constant in form and size.
They may originate terminally or subterminally on the branchlets.
In the former case the first indication of such a development is a
slight swelling of the hyphal end accompanied by a well marked
change in the protoplasm (fig. 11, a-c). Before reaching its normal
size, the zoosporangium becomes cut off from the hypha by a
septum, and papillae of dehiscence begin to appear. When pro-
duced subterminally, the mature zoosporangium may be borne on
a more or less elongated branchlet, as previously noted, which
originated from the parent branch directly below another repro-
ductive body (fig. 6), may be sessile (fig. 12, b), or even develop as
swollen segments cut off by septa (fig. 12, a). The latter method
when continued produces a chain of zoosporangia (fig. 59)- As a
result of cutting off the ends of fertile branches, zoosporangia may.
bud out from the remaining parts in various places. In certain
instances the contents of the injured branches give rise to zoospores
without any modification in form. :
The zoosporangia of B. Pringsheimii, after discharging thelr
zoospores, drop from the plant, leaving numerous scars. T his was
noted by THAXTER (9) and also by PETERSEN (4). I have never
observed this phenomenon to take place in B. strangulata.
1912] BARRETT—BLASTOCLADIA 350
empty zoosporangia may be seen still attached to the plants weeks
after they have ceased to produce reproductive organs.
As growth of the zoosporangium proceeds, there is a noticeable
condensation of the protoplasm in the center, around which can be
seen a number of indistinct vacuoles of irregular shape. There is
little apparent change from this condition until the zoosporangium
has reached its maximum size. The contents then become coarsely
granular and no vacuoles are apparent. This stage may persist for
some time if conditions for further development become poor. In
fact, it is in this stage that zoosporangia rest at times for days.
Suddenly the coarse granular character changes to one with fine
evenly distributed granules, and the whole contents assume a much
lighter appearance. After 15-30 minutes one can discern the for-
mation of areas surrounded by faint granular but irregular lines.
These become rapidly more prominent, and in a few minutes a
slight movement can be detected within the zoosporangium. The
areas represent the zoospores and their discharge is about to take
place (fig. 8). The papillae of dehiscence, sometimes numbering
as many as eight, become more and more extended and refractive
until one or more finally break open, permitting the zoospores to
escape. They pass out in single file, at first rather rapidly, then
more slowly as the pressure within the zoosporangium becomes
lessened (fig. 56). Being of a plastic nature, they squeeze through
the opening, arriving at the outside irregular in form, and very
commonly with their cilium held in the opening by the next
emerging zoospore. After a few seconds they move slowly away,
assuming their normal form. -
The zoospores are oval to elliptical, not infrequently slightly
Ovate, in which case the narrower end is the anterior one. The
number of cilia varies from one to three, and they are attached at
the posterior end. From a large number of careful examinations
of both living and stained preparations of zoospores, I assume that
the uniciliated condition is the typical one, as it occurs much more
frequently than the other two types. The triciliated zoospore is
rarely seen, while the biciliated form is common. The zoospores
of B, Pringsheimii possess, according to THAXTER (9), one or two
360 BOTANICAL GAZETTE [NOVEMBER
cilia. He considered the latter number the typical one, while
PETERSEN (4) has described the zoospores as uniciliate.
The zoospore contains a large subtriangular centrally located
body which resembles a large nucleus (fig. 23). THAXTER observed
this body and described it as follows: ‘‘The nucleus is very large
and subtriangular in outline, its base connected with that of the
cilia by a fine strand of protoplasm.” Fig. 24 shows very distinctly
the connection of the cilium with the base of the large central body.
The zoospore was killed with a 1 per cent solution of osmic acid and
stained with an alcoholic solution of Magdala red. In the process
the outer portion of the zoospore broke away, leaving the cilium
still attached to the central body as represented. There can be
observed in properly killed and frequently in living zoospores a
more or less hyaline globule situated at the base of the central body,
which contains a highly refractive granule. This body is undoubt-
edly the nucleus of the zoospore and will be more fully discussed
later. The zoospore also contains groups of large and small
granules, evidently of a fatty nature, which are principally located
in front and to the rear of the so-called central body.
In movement the zoospores proceed in a more or less direct
course, with a slight swaying of the body, and at times accompanied
by a slow rotation on the longitudinal axis. If supplied with
sufficient oxygen they may continue to swim for a number of hours,
but when mounted on a‘slide under a cover glass, where the oxygen
supply is small, they soon cease movement and germinate.
Fig. 28 shows a section of a young reproductive body, prée-
sumably a young sporangium, stained with iron-alum hematoxylin.
The protoplasm is granular, vacuolated, and contains distributed
throughout it prominent nuclei and large and small deeply staining
bodies to which reference has already been made.. The number of
nuclei is at first small, and there is apparently no marked passage
of the nuclei from the adjacent portions of the mycelium such as
occurs in the developing sporangia and sexual organs of many
other Phycomycetes. The nuclei in the upper half of the sporan-
gium are in various stages of division. This condition may be
found in young rapidly growing hyphae and principally at the grow-
ing point. As growth proceeds the number of nuclei rapidly
Tor2] BARRETT—BLASTOCLADIA 361
increases, until 40-70 are produced, usually about 60 in average-
sized sporangia. About the time the zoosporangium reaches its
full size the nuclei arrange themselves about the periphery. A
large number of the sections show this condition, which seems to
indicate that the zoosporangia rest in this stage. This condition
probably agrees with that described above for the living specimen
in which the protoplasm is coarsely granular.
Fig. 29 represents a section of a zoosporangium which is entering
the stage of zoospore formation. The large nuclei have become
distributed throughout the more coarsely granular protoplasm.
The number and size of the deeply staining bodies has increased,
while some of them show a vacuolate condition. On some of the
nuclei can be seen deeply staining masses of small size. Other
nuclei are associating themselves, more or less closely, with some
of the larger masses.
This condition is carried still farther in fig. 30. In a number
of cases the nuclei are more or less imbedded in the deeply stained
bodies, in others they are still free from them. These stages very
probably correspond to the more or less homogeneous stage of the
living zoosporangium which just precedes the differentiation of the
zoospores. Fig. 30 also shows the beginning of segmentation of
the protoplasm. It proceeds from the periphery inward in a more
or less radial direction, much as described by HARPER (2) for
Synchytrium decipiens. The lines of division are first recognized
as rows of granules, at first more or less indefinite, but which become
more and more apparent until they are seen entirely to outline the
spore mass.
Fig. 31 represents a part of a section of a sporangium in which
Segmentation is almost complete. The limiting surfaces of the
Spore masses in a number of cases have separated. Apparently
contraction has taken place, which would indicate that the mature
zoospores occupy less space than the original masses of protoplasm
from which they are formed. HARPER (2) observed that shrinkage
of the protoplasm takes place in the early stages of cleavage in
Synchytrium decipiens, and suggested a loss of water as the cause.
He also observed the open spaces formed by the separation of the
segmented masses.
362 BOTANICAL GAZETTE [NOVEMBER
It will be observed (fig. 31) that the nuclei with their associated
material have assumed a more regular form. The nucleus itself
is drawn out to a point which, in some cases, extends to the very
limits of the spore. No indications of cilia have been observed at
this stage, but they can be seen occasionally in a later stage, that is,
at the time of discharge of the zoospores. The condition of the
nucleus described strongly suggests that the cilia have their origin
through its direct influence.
Segmentation usually results in the formation of uninucleate
zoospores. Occasionally, however, one may find binucleate z0o-
spores with the nuclei in the same or different central bodies, or
what I shall hereafter call food masses or bodies. Fig. 34 shows
normal zoospores ready to escape from the zoosporangium. Fig.
35 shows the two types of binucleate zoospores of the same age as
those in fig. 34.
In preparation for germination the zoospore comes to rest, takes
on a spherical form, and gradually absorbs its cilium, which in the
process commonly becomes enlarged at the end (fig. 25). The
large reserve food body disappears and a large number of variously
sized granules take its place. In the course of 10-20 minutes the
germ tube makes its appearance and grows rapidly, forming the
basis for the subsequently developed rhizoid system (figs. 26, 27,
2,a-c). The body of the zoospore forms the basal cell of the plant.
Fig. 36 represents a zoospore stained with iron-alum hema-
toxylin, preparing to germinate. As described above, the reserve
food mass has apparently broken up into a number of deeply
staining granules. As the germ tube elongates, the nucleus”
increases in size (fig. 38) and finally divides to form two (fig. 39)-
Accompanying the rapid growth of the young plant the protoplasm
becomes more and more vacuolated and finally granular (fig- 40).
Stained preparations of germinating zoospores beyond the four-
nucleate stage were not obtained.
Just what the nature of the so-called reserve food bodies is has
not been determined. Fig. 41 shows a zoospore killed with iodine
solution. The nucleus and some granules show distinctly, while
the large food body in most cases is invisible. Fig. 42, killed with
weak Flemming solution, reveals that body clearly, and also the
1912] BARRETT—BLASTOCLADIA 363
blackened condition of the granules, which indicates their fatty
nature.
Papillae of dehiscence occur on the zoosporangia of many
' Phycomycetes. In most cases they have been described as small
swollen areas in the sporangial wall, or tips of exit tubes which
become gelatinized and allow the emission of the zoospores to take
place. An interesting condition is found in Rhipidium americanum.
The zoosporangium possesses a double wall; the outer forms a cap
over the papillae, which, on the discharge of the zoospores, becomes
lifted up by the protruding inner wall; the latter forms a cylinder
or vesicle which incloses the diackanbes zoospores; it ruptures
immediately, setting them free (THAXTER 10). A similar condi-
tion prevails for Sapromyces.
So far as I have been able to learn, the structure and behavior
of the papillae of B. strangulata differ from anything yet described.
In the living sporangium the papilla possesses what appears to be
an outer highly refractive hyaline convex cap, with a less refractive
area between it and the protoplasm of the sporangium. The
external part becomes more and more convex as gelatinization
proceeds (fig. 8). Just before the disappearance of the outer part
it loses its high refractive power to some extent, and has the sem-
blance of glycerine. Suddenly the thin ungelatinized portion of the
wall breaks, and becomes forced out, leaving a ragged rim, many
times, about the opening. The adjacent gelatinized part is imme-
diately dissolved in the surrounding water, and to all appearances
the exit pore is open. In a few seconds the zoospores begin to
escape. Under what seem to be normal conditions, a vesicle is
formed which incloses at least a part of the zoospores on their
discharge. This vesicle soon breaks and the zoospores are set
free (fig. 13). Frequently no such vesicle can be seen, and in such
cases the zoospores escape as shown in fig. 14. The formation of
such an inclosing membrane immediately suggested a double wall
to the zoosporangium, and also that it was the inner of the two
which either protruded as in Rhipidium americanum, or that by
its gelatinization it was enabled to stretch out in the form of a
in sac.
On the examination of sections it was found that neither assump-
364 BOTANICAL GAZETTE [NOVEMBER _
tion was correct. Fig. 9 shows a section through an immature
papilla and the adjacent wall of the zoosporangium. It is very
evident that the wall is single, but that there are two distinct parts
to the gelatinized plug of the papilla. The plug has a strong
affinity for stain, especially safranin. The ungelatinized part of
the wall is seen as a thin unstained layer extending over the convex
plug. The wall immediately surrounding the papilla is thickened
so as to form a sort of collar. . This is clearly seen in empty
sporangia. Fig. 10 shows the two parts of the plug separated as a
result of cutting the section. It will be seen that the inner portion
bears a close relation to the protoplasm. Such a section is common.
In those sections which show a contraction of the protoplasm from
the wall of the zoosporangium, almost invariably it is found to
adhere closely to the inner part of the plug, whether that remains in
place or not. It is this part of the plug that has the less refractive
power in the living state and that on stretching out forms the
vesicle referred to above. Very probably gelatinization is brought
about by the action of an enzyme secreted by the protoplasm in the
region about the papilla, which may account for the close relation
between the two just described. Apparently the outer part of the
plug becomes more thoroughly gelatinized than the inner, while
the outer thin unstained part of the wall over the papilla is little
or not at all affected.
This condition may be explained, it seems, by assuming that
the wall of the zoosporangium is made up of lamellae which differ
slightly in composition and which are differently affected by the
gelatinizing agent. This assumption is strengthened by the fact
that in a few sections the condition illustrated in fig. 9 was observed,
that is, the line separating the two portions of the gelatinized plug
extended slightly into the sporangial wall.
Development of resting sporangia
The resting sporangia agree in general to similar bodies described
by Rerscw (6) and THaxter (9) for B. Pringsheimit, and by
THAXTER (Q) for B. ramosa. In B. Pringsheimii they are called
resting spores by THAxTER, and are considered as doubtful oospores
by Remscu. They are indicative of the older condition of the
1912] BARRETT—BLASTOCLADIA 365
plant, and when mature are deciduous. According to THAXTER,
the mature resting spore is surrounded by two walls, an outer,
thin and smooth, and an inner, thick and apparently perforated or
pitted. He did not study a section of the wall, hence was not able
to determine the structure definitely. They possess several large
oil globules, are oval to pyriform, and vary in form almost as much
as the zoosporangia.
In B. ramosa the resting sporangia, or spores, are “bluntly
rounded, gradually narrower toward a truncate base, and about
30X11.” In this species the resting spores are less variable in
form than those of B. Pringsheimii, but vary somewhat in size.
The walls are very little thicker than those of the sporangia.
Resting spores of neither species were seen to discharge zoospores
or to germinate.
The resting sporangia of B. strangulata, for such they are, as will
be shown later, are very constant in form and vary only slightly in
size. They are ovate in form, with the narrower basal end truncate
(fig. 15). As previously noted, they occur at almost any age of the
plant, depending on the conditions of growth, and remain attached
at maturity. They have their origin, in general, in the same
manner as the zoosporangia, and in the younger stages cannot be
distinguished from them. The wall begins to thicken early, and
this, together with the absence of papillae, indicates that resting
sporangia are developing. When they are mature they possess
three walls, an outer and an inner, thin, smooth, and hyaline, and
a middle, thick, perforated, and orange colored. The peculiar
perforated nature of the middle layer can easily be made out in
sections of mature resting sporangia. The pores are conical in
Shape, with the broad end outward. The greatest diameter is
0.8 and the least 0.3. Fig. 16 shows a surface view, while
fig. 17 is a diagrammatic representation of a cross-section, showing
the pores and the inner and outer walls. The pores are more or
less regularly arranged in rows, as seen in fig. 15.
he mature resting sporangia contain a number of oil globules
which are not strikingly noticeable as they are in many other resting
bodies of a similar nature. In describing these bodies for B.
Pringsheimii, PETERSEN (4) says: “Peculiar pointed or rounded
366 BOTANICAL GAZETTE [NOVEMBER
cylindrical resting spores with a flat base and remarkably porous
walls, without much content, appear in place of the zoosporangia.”
In the young stages the protoplasm has much the same appear-
ance as that of the young sporangia. Fig. 32 represents a section
of a developing resting sporangium in which the nuclei are arranged
about the periphery. The central mass of granular protoplasm,
containing several reserve food bodies, is surrounded by prominent
vacuoles. In the mature sporangium the protoplasm forms a
definite regularly arranged network in which the nuclei are dis-
tributed (fig. 33). There are present, also, deeply staining masses,
more or less irregular in shape, which probably represent the fusion
of several reserve food bodies.
On germination the contents of the resting sporangia escape
in the form of zoospores not unlike those formed in the zoosporangia.
According to all observations and tests made, it is necessary that the
resting sporangia pass through a period of rest before germination.
I have not found any to germinate that were not at least one month
old. This applies to culturés developed both in water and on agar.
On the transference of the sporangia to fresh water there is no
apparent change for some time. After 18-20 hours the two outer
walls become cracked open, due very probably to the absorption
of water. Sometimes they crack in several places, bringing to view
the inner hyaline wall which bears one or more papillae of dehis-
cence. In a short time the normal discharge of zoospores takes
place (fig. 22).
Nuclear division
_ The resting nuclei are usually spherical in form and contain s
large deeply staining body which I assume to be a chromatic
nucleolus. Surrounding this body is a fine granular cytoplasm
which can be seen forming an irregular network (fig. 43)- They
vary in size from very small, almost invisible dots, to those with a
diameter of 6-7 ». The smaller are found in the actively growing
parts where nuclear division more commonly takes place. he
mode of division is rather unusual and suggests a form of amitosis-
The first indication of such a nuclear division is a change of the
chromatin mass from the more or less normal spherical to an elon-
gated form (figs. 48, 52). A transverse line of division is next
1912] BARRETT—BLASTOCLADIA 367
seen (fig. 47). The two parts then round up (figs. 45, 53), separate
(figs. 49, 51), and appear as two large nucleoli. A wall is finally
laid down between the daughter chromatin masses, and the two
nuclei result (figs. 44, 55). Frequently nuclei may contain three of
these bodies (fig. 50). Evidently one of the two daughter masses
of the first division divided before any nuclear wall separated them.
In dividing nuclei stained with iron-alum hematoxylin, there is
a faintly staining homogeneous substance connecting the separating
chromatin masses, which suggests some sort of a spindle. Two
explanations suggest themselves: (1) that we are dealing with
direct nuclear division and that the faintly staining substance is
the cytoplasm contracted about the dividing chromatin masses;
and (2) that division is indirect and that the large chromatin mass
represents a single chromosome.
It seems unusual, if not improbable, that such a highly differ-
entiated plant in so many respects should possess only a direct
method of nuclear division. The fact, however, that no sexual
organs are known for any of the species of the genus may have some
bearing on the question. Humpurey (3) found a very similar
nuclear division to take place in the hyphae of Achlya apiculata.
From all observations yet made, I am inclined to hold to the view
that we are dealing with a peculiar type of mitotic division. Further
Studies concerning the question are contemplated.
Since the species appears to be a new one, I add here a descrip-
tion giving the more important characters as observed by the
writer,
Blastocladia strangulata, nov. sp.—Main axis oval to cylindrical,
divided at the base into a number of rhizoidal divisions; above
giving rise to a one to several times dichotomously or umbellately
branched system whose ultimate branchlets produce terminally
or subterminally zoosporangia and resting sporangia; definite
constrictions and perforated pseudo-septa at the points of branch-
ing. Zoosporangia, oval to nearly spherical (50-63X40-52 ),
Possess several papillae of dehiscence, and produce a compara-
tively small number of rather large zoospores. Zoospores 12X8 #,
with one to three cilia, usually one. Resting sporangia ovate to
nearly oval, with a truncate base, 45X35; the wall consists of
368 BOTANICAL GAZETTE [NOVEMBER
three layers, the middle thick, perforated, and orange colored; on
germination giving rise to zoospores. Whole plant 200-2000 #
high, its main axis 40-100 » in diameter.
Found but once, and on an aphid in a water culture made from soil taken
from the bottom of an almost dry inland pond near Ithaca, N.Y.?
Axi primario ovato ad cylindricum, basi divisionibus rhizomatoideis
numerosis, sursum copiose dichotome v. subdichotome ramoso; ramosis
intervallis constrictis; pseudo-septis perforatis intra ramulorum basim formatis;
_ zoosporangiis ovalibus ad sphaeroidea, 50-63 40-52 mw, papillas dehiscentes
paucas ferentibus; zoosporis ovalibus, 128 p, cilio plerumque simplici
ornatis; sporangiis perdurantibus, rotundatis, basim versus graditim angus-
tioribus et truncatis, 4535 m, zoosporis foventibus.
Hab. Ad aphid in aqua, Ithaca,
Summary
1. The plant resembles in general the other species of the genus.
Its mycelium is definitely constricted, which fact, it seems, definitely
places the genus in the family Leptomitaceae.
2. It possesses peculiar perforated pseudo-septa which are
formed at the constrictions, and which in a way are comparable
to the “‘cellulin rings” of other members of the Leptomitaceae.
3. Zoosporangia are provided with a number of papillae of
dehiscence distributed over the surface, which are formed as the
result of the gelatinization of small circular areas of the wall. The
resulting plug is made up of two distinct parts, the inner of which
forms a vesicle into which the zoospores escape at the time of their
discharge.
4. The zoospores possess a large centrally located subtriangular :
mass of apparently some reserve food substance, probably proteid
in nature, at whose base is located the nucleus. They are typically
uniciliated, with the cilium in direct relation to the nucleus.
5. Resting sporangia possess a three-layered wall; the , outer
and inner layers thin and hyaline; and the middle thick, perforated,
and orange colored. After a period of rest of several weeks,
germination takes place by the formation of zoospores.
* During May and June rorr this species appzared several times in water cul-
tures made from two garden soils one-fourth mile apart near Urbana, Ill. As it WaS
found in soil collections made at different times and parts of the gardens, es
evidently not rare in those particular locations. ~
1912 BARRETT—BLASTOCLADIA 369
6. On germination the zoospore produces a germ tube which
forms the basis of the rhizoid system, while the body of the spore
becomes the basal cell of the plant.
7- Nuclear division is somewhat unusual, apparently, and
reminds one of amitosis. It seems to the writer, however, that it
is more probably a form of mitotic division dealing with a single
large chromosome.
LITERATURE CITED
I. Fiscuer, A., RaBENHORST’s Kryptogamen Flora von Deutschland. I+: 367.
1892.
2. Harper, R. A., Cell division in sporangia and asci. Ann. Botany 13:467-
525. pls. 24-26. 1899.
3- Humpnrey, J. E., The Saprolegniaceae of the United States, with notes on
other species. Trans. Am. Phil. Soc. 173:63-148. pls. 14-20. 1893.
4- PETEeRsEN, H. E., Studier over ferskvands-phykomyceter. Saertryk af
Bot. Tidssk. 29: 345-440. figs. 27. 1900.
5- Princsuem, N., Ueber Cellulinkérner, eine Modifikation der cellulosen
K6rnerform. Bex Deutsch. Bot. Gesells. 1: 288-308. pl. 7. 1883.
6. Remnscu, P. F., Beobachtungen iiber einige neue Saprolegnieae, etc.
Jahrb. Wiss. Bot. 11: 283-311. pls. 14-17. 1878.
7. Scuréter, J., ENGLER und Prantt, Nat. Pflanzenfam. I*:103. 1893
8. THaxter, R., New or peculiar aquatic fungi. 2. Mage Fischer and
Myrioblepharis, nov. gen. Bor. Gaz. 20:477-485. pl. 31. 1895.
_———, New or peculiar aquatic fungi. 3. Biostedadia Bor. Gaz.
21°45-52. pl. 3. 1806.
—, New or peculiar aquatic fungi. 4. Rhipidium, Sapromyces, and
Araiospora, nov. gen. Bor. Gaz. 21:317-331. pls. 21-23. 1
Io.
EXPLANATION OF PLATES XVIII-XX
Fic. 1.—Biciliated zoospore.
Fic, 2.—Different stages in the germination of the zoospore.
Fic. 3.—Young plant with basal cell showing rhizoids and two branches
which are beginning to branch dichotomously.
Fic. 4.—Young plant started on potato agar and subsequently transferred
to water where sporangial development took place. ;
Fic. 5.—Plant similar to the one shown in fig. 4, with an empty sporangium
and another almost mature below it.
Fic. 6, ce branch with sympodial arrangement of resting sporangia.
Fic. 7.—Resting sporangia more closely arranged on the branchlet, a more
frequent tere in old cultures.
370 BOTANICAL GAZETTE [NOVEMBER
Fic. 8.—A mature sporangium showing zoospores differentiated and two
papillae of dehiscence.
Fic. 9.—A stained section of a papilla of dehiscence.
Fic. 1o.—Another section of a papilla of dehiscence, showing the proto-
plasm and attached inner portion of the plug drawn away from the wall.
Fic. 11.—Early stages in the development of zoosporangia.
Fic. 12.—A mature plant, showing the rhizoid system, manner of branch-
ing, and arrangement of reproductive bodies.
Fic. 13.—A mature sporangium discharging its zoospores into a thin
vesicle which soon ruptures.
Fic. 14.—A mature zoosporangium discharging its zoospores without the
formation of a vesicle.
Fic. 15.—Resting sporangium, showing the relative position of the pores
in the much thickened wall.
1G. 16.—An enlarged portion of the surface of a resting sporangium
Fic. 17.—A diagrammatic representation of a microscopic section af -
wall of a resting sporangium
Fic. 18.—Different stages in the development of the pseudo-septa located
at definite constrictions in the hyphae.
IGS. 19-21.—Microscopic sections through such a septum as shown in
fig. 18, a, giving the various appearances that result.
IG. 22.—Germinating resting sporangium: outer walls cracked open,
exposing the inner thin wall bearing papillae of dehiscence.
Fic. 23.—A zoospore showing the nucleus with its accompanying mass of
reserve food material, and two cilia.
Fic. 24.—Zoospore killed with a 1 per cent solution of osmic acid and
stained with Magdala red; the outer portion of the zoospore broke away,
ree the reserve material and nucleus with the single cilium attac ched.
25.—Zoospore coming to rest preparatory to germination; contraction
of ne ans taking place and contents becoming granular.
Fics. 26, 27.—Early stages in germination of the zoospore: from living
specimens.
Fic. 28.—Section of a young zoosporangium, showing nuclei in divis
and also several large deeply staining food bodies
Fic. 29.—Section of a zoosporangium at the time of early nuclear ass0-
een Dass the reserve food material preparatory to pao formation.
- 30.—Later stage than that shown in fig. 29: many nuclei more ys
less Geshe: in the reserve food material; lines of segmentation appearing at
the periphery.
Fic. 31.—Section of a zoosporangium in which segmentation has taken
place.
Fic. 32.—Section of a developing resting sporangium and a sub-branch.
Fic. 33.—Section of a mature resting sporangium.
ion
PLATE XVII
LIV
’
BOTANICAL GAZETTE
BARRETT on BLASTOCLADIA
PLATE XIX
BOTANICAL GAZETTE, LIV
54
%
de/.
46
BARRETT on BLASTOCLADIA
43
BOTANICAL GAZETTE, LIV | PLATE XX
59
BARRETT on BLASTOCLADIA
1912] BARRETT—BLASTOCLADIA 371
Fic. 34.—Stained zoospore from a ripe zoosporangium: nuclei very
distinct; ie abion hematoxylin.
IG. 35.—Binucleate zoospores.
Fic. 36.—Zoospore preparing for germination: the large reserve food
body is broken up into small granules.
1G. 37.—Uninucleate germinating zoospores
Fic. 38.—Germinating zoospore showing the large nucleus just previous
to division,
Fic. 39.—Binucleate stage of a germinating zoospore,
Fic. < —More advanced condition of a germinating zoospo
Fic. 41.—Zoospore killed with iodine: nucleus clearly Seok but the
food neg is Sevieibas.
1G. 42.—Zoospore killed with weak Flemming’s solution: granules sur-
rounding nucleus and reserve food body stained black.
Fic. 43.—Resting nucleus, showing : large deeply staining chromatin
mass surrounded by faintly staining cytoplasm.
Fic. 44.—Late stage in the division 5 a nucleus.
Frcs. 45-55.—Various stages of nuclear division.
Fic. 56.—A photomicrograph of zoosporangia discharging zoospores, and
resting sporangia.
IG. 57.—A photomicrograph of the plant from Mong fig. 56 was taken.
“99 58.—A photomicrograph of a small entire plan
G. 59.—A photomicrograph of a young plant oa on agar, which
ies the arrangement of zoosporangia in chains.
THE ORCHID EMBRYO SAC"
LESTER W. SHARP
(WITH PLATES XXI-XXIII)
During the spring of ro10 it was the writer’s privilege to visit
the island of Jamaica as one of a party of botanists from the Johns
Hopkins University under the leadership of Professor D. S. JOHN-
son. In view of the number of orchids available in the region
visited, it was suggested by Professor JoHNSON that a study of the
embryo sacs of these species, together with those of certain forms
growing in the University’s greenhouse at Baltimore, might for
several reasons prove of value.
The orchids, standing at the end of a great evolutionary line,
the monocotyledons, and reaching extreme specialization in other
features, may be expected to show instructive deviations from the
usual type of embryo sac, and it is through a study of such
deviations that a final explanation of the origin and nature of the
angiosperm embryo sac will probably be reached. They should also
be most likely to reveal the end result in the reduction of the female
gametophyte, which is seen occurring as one passes from the lower
heterosporous groups to the higher. Furthermore, the data at
hand on the orchid embryo sac, in part very suggestive, have been
somewhat scattered, the details being well known in comparatively
few forms, so that we have not known just what relation the cases
reported bear to any general situation which may be present among
orchids. ) ;
Although the number of additional species here described 1s
small for a group as large as the Orchidaceae, they are well scattered
throughout the family, so that taken together with species PF&
viously described they place us in a better position to draw CoM
clusions on the general tendency of the group. :
For the sake of clearness the different forms will be cons!
separately, and only two or three of them in detail.
* Botanical contribution from the Johns Hopkins University. No. 25-
dered.
Botanical Gazette, vol. 54] ae
1912] SHARP—ORCHID EMBRYO SAC 373
Epidendrum variegatum Hook.
The course of development in this species corresponds in many
respects very closely to that recently reported for Epipactis pubes-
cens (BROWN and SHARP 2), in which an 8-nucleate sac of the ordi-
nary type is derived from one or less frequently from four
megaspores. In Epidendrum variegatum, while the majority of sacs
developed from one megaspore, the proportion of cases in which
four are concerned is apparently greater than in Epipaciis.
The archesporial cell, as in all of the other species examined, is
hypodermal in position, and since it cuts off no parietals it is at the
same time the megaspore mother cell. After passing through
synapsis (fig. 1) and the other prophases preceding reduction, the
nucleus of this cell divides: The position of the spindle and the wall
formed upon its fibers is variable, which seems to be an important
factor in determining the nature of the subsequent development.
The spindle may be formed near the micropylar end of the
mother cell, the resulting daughter cells in this case being very
unequal in size, or the spindle may arise near the middle, the
daughter cells then being approximately equal. Between these
two positions of the spindle all gradations are found.
In the event of an unequal division the subsequent development
is as follows. The small micropylar daughter cell at once begins to
disorganize, while the large inner one divides (fig. 2) to form two
megaspores. Of these the inner one only remains functional, the
outer one disorganizing along with the micropylar daughter cell
(fig. 3). The nucleus of the functioning megaspore divides without
the formation of a wall (fig. 4) and the resulting nuclei again divide
freely to form the 4-nucleate sac (fig. 5). At the next division
(fig. 6) cell plates appear on the fibers of all four spindles, but those
formed in connection with the chalazal nuclei usually disappear,
so that the antipodals are in most cases represented by free nuclei.
When the division of the megaspore mother cell is equal (fig. 7),
the cell plate which forms upon the spindle fibers is ephemeral and
the two daughter nuclei are left free in the same cell cavity. Vacuo-
lation occurs in the cytoplasm, usually in the region between the
nuclei (fig. 8), but at times near the ends of the cell with the two
nuclei at the center (fig. 9). At the division of these nuclei distinct
374 : BOTANICAL GAZETTE - [NOVEMBER
cell plates appear on the spindle fibers but do not persist, so that the
four resulting nuclei remain free in the cytoplasm (figs. 10, II).
Since these have arisen by two successive divisions from the nucleus
in which the heterotypic prophases occur, they are to be regarded
as megaspore nuclei, and any one of them is thus the morphological
equivalent of the nucleus shown in fig. 3. By one further division
these four megaspore nuclei give rise to an 8-nucleate sac similar
in all essential points to that derived from a single megaspore. An
egg apparatus of the ordinary type is organized; the antipodal
nuclei may or may not be separated by walls; and the two polar
nuclei meet in the vicinity of the egg (fig. 12). ;
The various stages described in the foregoing paragraph may
be distinguished from those in the development of a sac from a
single megaspore by the absence of disorganized cells at the micro-
pylar end. In later stages these latter become indistinguishable
from the disorganized contents of the epidermal cells of the nucellus,
so that it is then unsafe to use them as evidence, but there appears
to be nothing against the assumption that the fate of the embryo
sac is the same whether it has been derived from one megaspore OF
from four. :
In this Epidendrum, as in Epipactis, two megaspores evidently
take part in the formation of the embryo sac in a few cases. This
condition results when the division of the megaspore mother cell is
very unequal and that of the inner daughter cell equal, the separat-
ing wall at the second mitosis being ephemeral.
The pollen tube enters the sac, disorganizes the two synergids,
and liberates two male nuclei. One of these fuses with the egs
nucleus, while the other fuses with the two polars (fig. 13). The
endosperm nucleus formed by the latter fusion undergoes 10
division, but degenerates along with the three antipodal nuclei
(fig. 14).
The first few divisions of the fertilized egg are transverse,
resulting in a filamentous proembryo of a varying number of cells.
Longitudinal walls soon come in, and for a time the cells show @
very regular two-ranked arrangement (fig. 15). Fig. 16 represents
a proembryo of E. verrucosum, in which the number of transverse
divisions has been very high, forming a filament of about 20 cells.
1912] SHARP—ORCHID EMBRYO SAC | 375
Figs. 17 and 18 show two stages in the development of the pro-
embryo of E. cochleatum. In these three figures is seen the general
course followed by the Epidendrum proembryo up to the stage
found in the mature seed. Multiplication of cells commences at
the chalazal end of the filament and extends upward, resulting in
an oval mass of cells which is still to be regarded as a proembryo,
since the body regions have not yet been marked out.
Epidendrum verrucosum Sw., E. cochleatum L., and E.
globosum Jacq.
The embryo sacs of these forms were briefly examined. In
the first two species stages were observed corresponding in all
essential features to figs. 1, 3, 5, 12, and 14. In E. globosum were
seen an ordinary 8-nucleate sac and a stage like that shown in
fig. 14. It thus appears that E. verrucosum, E. cochleatum, and
Probably E. globosum, agree with E. variegatum in the formation of
an embryo sac of the usual type from a single megaspore. The
investigation of these three additional species was not carried far
enough to determine whether they also show other methods of
developing the embryo sac or not.
Phajus grandifolius Lour.
The early stages in the development of the embryo sac in this
form correspond to those described above for those cases of Epiden-
drum in which but one megaspore is concerned in the formation
of the sac.
The megaspore mother cell (fig. 19) divides unequally and the
chalazal daughter cell again divides to form two megaspores. The
outer daughter cell and megaspore disorganize (fig. 20), while
the inner megaspore initiates the formation of the embryo sac. The
nucleus of this functioning megaspore by two successive divisions
gives rise to four; two of these lie at each end of the sac, the center
of which is occupied by a large vacuole. The two chalazal nuclei
undergo no further division, while those in the micropylar end
divide to four (fig. 21), which become organized into an egg appa-
ratus of the usual type and a free polar nucleus. This polar
migrates toward the base of the sac and lies near the two chalazal
376 BOTANICAL GAZETTE [NOVEMBER
nuclei which have failed to divide (fig. 22). These three may fuse
very soon (fig. 23) or they may remain distinct through the sub-
sequent stages (fig. 24). In fig. 23 the egg apparatus fills an
unusually large portion of the embryo sac.
The pollen tube discharges two male nuclei into the sac; one
fuses with the egg nucleus and the other becomes associated with
the free antipodal nuclei and micropylar polar (fig. 24). These
latter nuclei show little regularity in behavior; they may begin to
disorganize at any stage, but usually become more or less fused
before this occurs. In any event no endosperm is formed.
The fertilized egg divides transversely to form a short filamen-
tous proembryo, which attains a length of three or four cells before
the first longitudinal division occurs. At this stage the cell toward
the micropyle begins to elongate and push out into the surrounding
placental tissue as a haustorial suspensor (figs. 25, 26). Later this
dies away so that the proembryo in the mature seed is a simple
rounded mass of cells (fig. 27).
Corallorhiza maculata Raf.
In Corallorhiza the embryo sac develops in a manner similar
to that in Phajus grandifolius, as a comparison of figs. 28-33
(Corallorhiza) with figs. 20-24 (Phajus) will show. Consequently
the above description of the sac of Phajus applies in all essential
points to Corallorhiza, so that a separate account of the latter is
unnecessary.
The proembryo of Corallorhiza, as described by LEAVITT (6),
has a very long two-celled suspensor, which projects through the
micropyle and enters the tissue of the placenta.
Broughtonia sanguinea R. Br.
This species shows the same peculiarity described above for
Phajus and Corallorhiza. The innermost megaspore gives rise
to a sac with six nuclei, the primary antipodal nucleus dividing
only once. This division does not usually occur until the two
nuclei in the micropylar end divide to four, so that three spindles
are observed in the sac at one time.
Ig12] SHARP—ORCHID EMBRYO SAC 377
Bletia Shepherdii Hook.
This form affords another example of the derivation of the female
gametophyte either from one or from four megaspores, the course
followed being apparently connected with the position of the wall
formed at the division of the megaspore mother cell, as pointed
out in Epidendrum variegatum. The nucleus of this cell goes into
Synapsis (fig. 34) and at its division the spindle may lie near the
micropylar end of the cell or at its center. In the former case the
daughter cells are very unequal in size; the small micropylar one
degenerates, and the chalazal one divides to form two megaspores
(fig. 35). Of these the outer one disorganizes, while the inner one
enlarges and continues the development, by two successive divisions
giving rise to the 4-nucleate embryo sac (figs. 36-38).
When the division of the megaspore mother cell nucleus occurs
at the center of the cell (fig. 39) the wall formed is evanescent, the
two nuclei thus being left free in the same cell cavity (fig. 40).
These nuclei divide simultaneously, as shown in fig. 41; here the
wall laid down at the first mitosis in the megaspore mother cell is
still visible as a remnant, and several chromosomes are seen lying
in the cytoplasm apart from the spindles. The four nuclei which
‘thus arise, being the product of two successive divisions from the
nucleus in which the heterotypic prophases occur, are to be regarded
aS mMegaspore nuclei (fig. 42).
Except for the absence of disorganized cells at the micropylar
end, the 4-nucleate sac formed as just described is similar in appear-
ance to that produced from a single megaspore (cf. figs. 38 and 42).
Since the active growth of the sac results in the complete oblitera-
tion of the disorganized cells, it is not possible to determine by
inspection of the later stages from which type of 4-nucleate sac
they have been derived, but there seems to be no reason why either
type or both should not continue the development, which from this
Point onward is exceedingly irregular. Abnormalities of many
kinds were observed, and all that can be attempted here is to indi-
cate one or two of the common tendencies shown.
In only three cases were there seen more than four nuclei in the
embryo sac before fertilization. In one of these (fig. 43) the two
micropylar nuclei had divided, resulting in a 6-nucleate sac like
378 BOTANICAL GAZETTE [NOVEMBER
that described above for Phajus, Corallorhiza, and Broughtonia.
Tn each of the other two cases the antipodal nuclei had also divided,
forming an 8-nucleate sac (fig. 44). In none of these sacs were
walls observed separating the nuclei at either end.
Since no walls are present at the 4-nucleate stage, the nuclei are
free to wander about through the sac (fig. 45). They were seen in
all positions, but sooner or later they may all fuse to form one
large nucleus. The most common course followed is that repre-
sented in figs. 46-48; the nuclei near each end of the sac fuse and
the resulting fusion nuclei do the same. Often all four fuse at once;
sometimes only two fuse; and in many cases degeneration sets in
before any fusions have occurred.
Apparently the pollen tube may enter the sac and discharge
its two male nuclei at any of these stages. In fig. 49 it has extended
to an unusual distance into a sac like that shown in fig. 47, and in
fig. 50 the male nuclei have been. discharged into a sac containing
three nuclei in the central region. As far as could be determined,
no nucleus is set apart as the egg. The nuclei all lie in a group for
a time, and when disorganization does not occur at once they may
~ become fused (figs. 51-53). The large nucleus which results was
not observed to carry the development any farther.
In the material sectioned embryos proved to be exceedingly
scarce, and this condition is undoubtedly connected with the irregu-
larity and lack of organization shown by the embryo sac. The
two-celled proembryo in fig. 54 has evidently formed in a 6 oF 8-
nucleate sac, as beside the pollen tube there are in the micropylat
end two disorganizing nuclei, probably synergids, and in the chalazal
region a partially fused and degenerating group made up of at
least three. The next few divisions in the proembryo are transvers¢
(fig. 55), so that in its early stages it is filamentous, as in E
rum. Meanwhile the placental tissue develops rapidly fro
sides, completely filling the cavity of the ovary, and the few Pro
embryos found were lying in the small intervening crevices.
It is not unlikely that the great irregularity shown by Bletia a®
here reported may be due in part to the somewhat artificial con-
ditions under which the plant grew in the greenhouse.
m all
Igr2] SHARP—ORCHID EMBRYO SAC 379
Coelogyne massangeana and Pogonia macrophylla
In each of these forms the embryo sac contains eight nuclei
derived in the usual manner from a single megaspore.
As is well known, the ovules of orchids do not develop far unless
pollination has occurred. In most of the species here reported the
pollen tubes are found growing among the ovules before the pro-
phases of the reduction division in the megaspore mother cell; in
one or two species they are not present before the embryo sacs reach
the 2 or 4-nucleate stage. In reciprocal crosses between Phajus
grandifolius and Bletia Shepherdii it was found that in both cases
the pollen tubes develop in great numbers and grow down into the
ovarial cavity, in which ovules develop and produce embryo sacs
in smaller numbers but in the same manner as after normal pollina-
tion. In no case, however, was fertilization or an embryo seen
resulting from crosses between these two species. Thus the
stimulus necessary to the development of ovules with embryo sacs
may be furnished by foreign pollen incapable of effecting fertiliza-
tion.
Discussion
The main point of interest brought out in the above descriptions
is the variability in development within the species. It has been
noted by several workers that while the embryo sac of one species
of a genus or family is formed from the megaspore mother cell
directly, the sac of another species of the same group may arise
from one of a row of megaspores. The same variation within the
species has occasionally been observed, as in Salix glaucophylla
(CHAMBERLAIN 4) and Juglans cordiformis (KARSTEN 5). In the
Orchidaceae the latter condition appears to hold in a number of
cases, the fate of the megaspore mother cell apparently being
determined very largely by the position of the spindles at the first
two divisions, as pointed out above for Epidendrum variegatum and
Bletia She pherdii, and recently for Epipactis pubescens (BROWN and
SHARP 2),
This fluctuation results in a reduction in the number of divisions
Occurring between the megaspore and the egg. When a single
380 BOTANICAL GAZETTE [NOVEMBER
megaspore produces the 8-nucleate sac there are three such divi-
sions; when a similar sac arises from a daughter cell, two mega-
spores thus taking part in the process, there are two divisions; and
when the megaspore mother cell gives rise to the sac directly, four
megaspores are involved and the egg is separated from the mega-
spore by but one division.
The tendency to mature the egg earlier and earlier in the
ontogeny of the gametophyte is very conspicuous among gymno-
sperms, and it was hoped that among these very advanced angio-
sperms the end result of this specialization might be found—the
megaspore itself functioning as an egg. The number of cases in
which the elimination of but one more division would result in this
situation is fairly large, and includes sacs with 4 nuclei (Cypri-
pedium, Pace 7), 8 nuclei (Lilium, various orchids, and many
others), and 14 nuclei (Pandanus, CAMPBELL 3). That the reduced
condition is being approached by such a variety of ways allows us
to expect: with confidence to discover in some plant a situation
exactly paralleling that in animals, in which the product of the
reduction divisions at once becomes the egg. :
Scarcely less striking than the variability within the species 1S
the uniformity shown by the embryo sac throughout a group 5°
varied in structure and habit as the orchids. In spite of the incon-
stancy in the methods of sac development the end result is remark-
ably uniform. The ordinary 8-nucleate sac, developed from a single
megaspore, is the prevailing condition in the group. Beside the
species here reported, it is found in Calopogon (Pace 8), Habenaria
(Brown 1), Epipactis (BROwN and Suarp 2), Gymnadenia (WARD
10), Orchis (STRASBURGER 9), and others. :
e influence of the surrounding conditions upon the behavior
of the nuclei during the formation of the embryo sac has recently
been considered in some detail (BRowN and SHARP 2). The fact
. brought out in the present account lend further support to the idea
there expressed, namely, that the causes for the behavior of the
nuclei are to be sought largely in factors external to the nucle!
themselves. The conditions under which the ovules of orchids
develop within the ovary are undoubtedly much the same 1m the
1912] SHARP—ORCHID EMBRYO SAC 381
various species, while the ovules themselves are almost exactly
alike in structure, varying only in the matter of dimension. Thus
since the archesporial cell in the different species has the same
general form and initiates a series of stages developing under prac-
tically the same conditions, a general similarity in result is to be
expected.
Whether a row of megaspores is produced or not seems, as
already pointed out, to be largely dependent upon the position of
the spindles at the first two divisions. But megaspore mother cell
and functioning megaspore just before division are very much alike
in size, shape, and surroundings, and are acted upon by similar
external factors, so that whichever gives rise to the embryo sac
the same course is followed and the same end is reached.
The 6-nucleate embryo sacs of Phajus, Corallorhiza, and
Broughtonia seems to show a tendency toward a further reduction
of the vegetative portion of the gametophyte.
In all of the species examined the endosperm nucleus, whether
arising from the fusion of two or more nuclei, disorganizes without
dividing, so that Calopogon pulchellus (Pace 8), in which it may
give rise to as many as four free nuclei, remains as the only known
Case where endosperm is developed in orchids.
Summary and conclusions
1. The archesporial cell in all of the species examined is hypo-
dermal and cuts off no parietals, thus becoming at once the mega-
spore mother cell.
2. The megaspore mother cell in all of the forms studied divides
to two daughter cells, the chalazal one of which divides to form
two megaspores. The innermost megaspore gives rise to the
embryo sac.
3. In Epidendrum variegatum and Bletia Shepherdii the mega-
spore mother cell often gives rise directly to the embryo sac; in
such cases four megaspores take part in the formation of the sac.
4. In Epidendrum variegatum, E. cochleatum, E. verrucosum,
E. globosum, Coelogyne massangeana, and Pogonia macrophylla the
embryo sac is of the ordinary 8-nucleate type. In Bletia Shep-
n
382 BOTANICAL GAZETTE [NOVEMBER
herdu the development is very irregular, but in fully mature sacs
eight nuclei are present.
5. In Phajus grandifolius, Corallorhiza maculata, and Brough-
tonia sanguinea the primary antipodal nucleus divides only once,
so that the embryo sac contains but six nuclei: four micropylar
and two chalazal.
6. Polar fusion occurs in all of the forms studied. In the
8-nucleate sacs the fusion is between two equivalent polar nuclei.
In the 6-nucleate sacs the micropylar polar migrates to the chalazal
end and there fuses with the two nuclei which have resulted from
the division of the primary antipodal nucleus. :
7. In all of the species in which fertilization was observed it 1s
of the usual type; one of the two male nuclei fuses with the egg
nucleus, while the other fuses with the two polars.
8. The proembryo commonly consists of three cells before the
‘first longitudinal division occurs; in Epidendrum a filament of as
many as 20 cells may be formed. In the mature seed the body
regions have not yet been marked out in the proembryo. :
9. In all of the species examined the endosperm nucleus dis-
organizes without dividing. ere
to. The ordinary 8-nucleate embryo sac produced by a single
megaspore is the prevailing condition among orchids. The causes
for the comparative uniformity throughout the group are to be
sought largely in the conditions surrounding the developing nuclel.
11. The orchids show very commonly a marked variation within
the species. This variability, seen chiefly in connection with
megaspore formation, is resulting in making an embryo sac
which the egg is removed from the megaspore by a single division
a conspicuous feature in the group.
12. Although endosperm has been eliminated and the seed
reduced to a very simple structure, the orchids as a group show 1m
their female gametophytes very little advance over other plants,
especially those lower in the line of the monocotyledons. ;
13. Reciprocal crosses between Phajus grandifolius and Bleiva
Shepherdii show that in these species the stimulus necessary t0 the
development of ovules with embryo sacs may be furnished by
foreign pollen incapable of effecting fertilization.
1912] SHARP—ORCHID EMBRYO SAC 383
To Professor DuNCAN S. JOHNSON are due acknowledgments for
many valuable suggestions during the progress of the work. The
writer is also indebted to Mr. Wirt1am Harris for placing at his
disposal material in the Hope and Castleton Botanic Gardens.
THE UNIVERSITY OF CHICAGO
LITERATURE CITED ‘
1. Brown, W. H., The embryo sac of Habenaria. Bort. GAz. 48: 241-250.
jigs. 12. 1909.
2. Brown, W. H., and SHarp, L. W., The embryo sac of Epipactis. Bor.
Gaz. 52: 439-452. pl. 10. 1911.
3- CAMPBELL, D. H., The posing sac of Pandanus. Bull. Torr. Bot. Club
36: 205-220. pis. ie. Ty:
4. CHAMBERLAIN, C. J., Comite bation to the life history of Salix. Bot. Gaz.
23:147-179. pls. 12-18. 1897.
5. Karsten, G., Uber die Entwicklung der weiblichen Bliithen bei einigen
Juglandaceen. Flora 90:316-333. pl. 12. 1902.
6. Leavirt, R. G., Notes on An embryology of some New — orchids.
Rhodora 3202-205. pl. 3 :
7- PACE, ae Fértilieation 3 in Dedpbiai Bor. Gaz. 443353~-374. pls.
24-27.
908.
8. The gametophytes of Calopogon. Bor. Gaz. 48:126-137. pls. 7-9.
Tgo9.
9. STRAsBURGER, E., Uber Befruchtung und Zelltheilung. 1878.
10. Warp, H. MarsHALL, On the embryo sac and development of Gymnadenia
conopsea, Quart. Jour. Micr. Sci. 20:1-18. pls. 1-3. 1880.
EXPLANATION OF PLATES XXI-xXXIII
All figures were drawn with the aid of an Abbé camera lucida, and show
magnifications as follows: figs. 1-15, X1200; figs. 16-18, X205; figs. 19-24,
X1125; figs. 25, 26; X513; fig. 27, X295; figs. 28-33, X1200; figs. 34-54,
%845; fig. 55, 475. |
PLATE XXI
Epidendrum variegatum scars
Fic. 1.—Synapsis in megaspore mother cell.
Fic. 2.—Inner daughter cell dividing; outer daughter cell disorganizing.
nas 3.—Functioning megaspore: outer daughter cell and megaspore
rgan
Fic, 4. a — sac: no wall on lingering spindle fibers.
384 BOTANICAL GAZETTE [NOVEMBER
Fic. 5.—Four-nucleate embryo sac.
. 1G. 6.—Division to form eight nu
G. 7.—Megaspore mother cell dividing yeah distinct wall formed.
Pw. 8.—Wall has disappeared; vacuole has formed
1G. 9.—Unusual arrangement of nuclei and eas nuclei in this case
have gone into resting condition.
1G. 10,—Division to form four nuclei; distinct cell plates formed.
Fic. 11.—Four-nucleate embryo sac (four megaspore nuclei): walls have
disappeared.
Fic. 12.—Eight-nucleate embryo sac.
Fic. 13.—Double fertilization. ;
Fig. 14.—Young proembryo: endosperm nucleus and antipodals dis-
organized.
Fic. 15.—Proembryo.
Epidendrum verrucosum Sw.
Fic. 16.—Filamentous proembryo.
Epidendrum cochleatum L.
Fics. 17, 18.—Two stages of the proembryo.
PLATE XXII
Phajus grandifolius Lour.
Fic. 19.—Synapsis i in megaspore mother cell.
Fic. 20.—Functioning megaspore: other daughter cell and megaspore
nized
Fic. 21.—Micropylar nuclei a chalazal nuclei remaining undivided.
Fic. 22,—Six-nucleate emb
Fic. 23.—Same: egg pete gee chalazal nuclei and micropylar
polar fusing.
Fic. 24.—Fertilization: second male nucleus associating with other free
nuclei of the sac.
Fics. 25, 26.—Proembryo showing micropylar cell growing out
haustorium.
Fic. 27.—Proembryo from mature seed.
Corallorhiza maculata Raf.
Fic. 28.—Inner daughter cell of megaspore mother cell dividing;
ea ORE cell disorganizing.
G. 29:—Four-nucleate embryo sac.
Fro. 30.—Micropylar nuclei dividing.
Fic. 31.—Six-nucleate embryo sac: micropylar polar has migrated to pase
of sac.
Fic. 32.—Fertilization has occurred; second male nucleus lying neat se
Fic. 33.—Young proembryo: second male and other free nuclei of the
fusing.
outer
PLATE XXI
BOTANICAL GAZETTE, LIV
SHARP on ORCHID EMBRYO SAC
BOTANICAL GAZETTE, LIV PLATE XXII
(ip \ :
ae 4 = :
SHARP on ORCHID EMBRYO SAC
BOTANICAL GAZETTE, LIV PLATE XXI1lIl
' EMBRYO SAC
1912] SHARP—ORCHID EMBRYO SAC 385
PLATE XXIII
Bletia Shepherdii Hook.
Fic. 34.—Synapsis in megaspore mother cell.
Fic. 35.—Inner daughter cell dividing to form two megaspores.
Fic. 36.—Functioning megaspore: outer daughter cell and megaspore
disorganized.
Fic. 37.—Two-nucleate embryo sac.
Fic. 38.—Four-nucleate embryo sac.
Fic. 39.—Megaspore mother cell dividing sally wall forming.
Fic. 40.—Wall has disappeared.
IG. 41.—Two nuclei dividing: wall formed at first mitosis still visible
as a remnant in this case.
Fic. 42.—Four-nucleate embryo sac (four megaspore nuclei).
Fic. 43.—Six-nucleate embryo sac: micropylar nuclei have divided.
Fic. 44.—Eight-nucleate embryo sac: no separating walls.
aig 45-48.—Usual fate of the 4-nucleate embryo sac; all the nuclei
Fics. 49-53.—Abnormal sacs into which male nuclei ree been discharged;
all the nuclei tend to fuse; p#, pollen tube; ¢, male nu
IG. 54.—Young proembryo evidently having ‘etnies in a normal sac.
Fic. 55.—Later stage of proembryo.
GROWTH STUDIES IN FOREST TREES
1. PINUS RIGIDA MILL!
Harry P. BRown
(WITH PLATES XXIV AND XXV)
The phenomenon of tree growth has long been a subject of
investigation. Sacus, Huco pe Vries, NORDLINGER, MER, the
RTIGS, WIELER, BtsGEN, von Mont, and a host of others have
worked on problems concerned with it, and many papers presenting
the results of investigations are to be found in the literature of the
last half-century.
As might be expected, the question has resolved itself into a
number of minor topics, each with its coterie of followers. Some
have placed particular stress on spring and summer wood forma-
tion; others have studied growth as related to external factors or
to inheritance. Various instruments have been devised to measure
tree growth, and one author (REUSs 12) goes so far as to assert
that thunderstorms cause a growth stimulus in trees. Investiga-
tions dealing with every phase of the subject are described 1n
exhaustive detail, and yet with rare exception there is a maze of
conflicting opinion sufficient to confuse even the careful reader.
The present studies were undertaken with a twofold purpose,
namely, to clear up disputed points regarding annual ring formar
tion in trees and to formulate laws of tree growth. Investigations
were carried on upon various forest trees with this idea in View-
The results of those on Pinus rigida are embodied in this paper-
Secondary thickening in trees arises as a general rule from 4
cambium which lives from year to year. This annually passes
through certain active and certain dormant periods. The latter
assertion, however, is to be taken in its broadest sense. In many
tropical woods the interruption to growth can be detected only with
a microscope, while in others it is totally lacking; the wood appeat®
* Contribution from the Department of Botany, Cornell University. No. 148-
Botanical Gazette, vol. 54] [386
*.
I912] BROWN—PINUS RIGIDA 387
as a homogeneous mass. The formation of this cambial layer takes
place the first year, and is brought about by the linking together,
so to speak, of the fascicular cambium of the primary bundles by
the formation of interfascicular cambial zones, the result being a
cylinder of merismatic tissue capable of division. There are, in
addition to this, however, certain other growth phenomena. In
the cortex of many trees, either near or remotely distant from the
primary cambium, secondary cambial zones arise, whose function
it is to form cork, the so-called cork cambiums. They are not
united in a ring, as is the primary cambium, but extend for com-
paratively short distances in a peripheral direction. Again, as met
with in the Cycadales and Gnetales (CoutTER and CHAMBERLAIN
4), successive bundle-forming cambiums sometimes arise toward
the periphery of the stem, and in such cases the life of the primary
cambium is generally very short. Further, among dicotyledons
there are a number of modifications of secondary thickening, par-
ticularly in underground parts. In the present studies, however,
it is the intention to confine investigation to growth as it normally
Occurs in trees, that is, to the activities of a cambium which has
certain active and certain dormant periods. ,
A number of specimens of Pinus rigida in the Cornell pinery as
well as others in the wild state were used. Those in the nursery
consisted of a number of individuals standing in a row which ran
approximately east and west. The land sloped gently to the south-
west and drainage conditions appeared to be good. The individual
trees were about 22 years of age and seemed to be in a thriving
condition. The height varied from 6 to 7 m., depending on the
vigor of the individual, and the average diameter at breast height
was 12cm. In 1909, when investigation began, the branches
extended to within 1.2m. of the ground. However, during the
year above mentioned, the trees were pruned to a height of 1.9 m.
above the ground. Experiments were carried on with six indi-
viduals of this series, which were numbered I-VI.
The trees in the wild state had better be described seperateli
since each was of different age and external factors varied with the
individual. For the sake of clearness they were designated as
? Exceptions to this rule occur, resulting in the so-called “ring-barked”’ trees.
388 BOTANICAL GAZETTE . [NOVEMBER
A, B,andC. These specimens were growing in a strip of woodland
about one mile north of the university campus. Conditions of
soil and light appeared to be good in every case, that is, to all
appearances the trees were not retarded.
Tree A was a magnificent specimen about 25 m. high; in other
words, it had practically reached its maximum size. The trunk
was slightly shaded to a height of 4.5 m. by an undergrowth com-
posed of white pine. There were no branches above for 18m.
until the crown began. The latter was but fairly developed, being
about what one might expect under forest conditions. At breast
height, the caliper measure was 50cm. A conservative estimate
of the age would be 100 years.
Tree B was a younger individual. Its height was approximately
20m., and crown development had progressed but poorly. At
breast height the caliper measure was 26 cm. The base was
entirely free of undergrowth, and light conditions were better inas-
much as there were no close neighbors. Tree B then differed from
tree A in (a) age, (6) light conditions, (c) crown development,
(d) height, and (e) diameter.
Free C was about the age of those in the nursery, namely 20~25
years, and rose to a height of 7m. Branches were borne practically
to the ground. The caliper measure was 11 cm. Illumination was
better on the south side, due to the close proximity of a road, while
on the north the underbrush encroached slightly.
Methods
Investigations began in the spring of 1909, and the last cutting
that year was made on July 6. Alternate cuttings were taken from
two different individuals at intervals about a week apart, S0 that
two weeks elapsed between incisions on any one tree. These were
made in the following manner. Beginning from the base of the
apical shoot, portions of the cortex and wood to a depth of at least
one annual ring were removed at intervals of about 50 cm. TwEe
cuttings were made in this manner with the aid of a sharp pocket-
knife, care being taken not to rupture the cambium. Each cuttiné
was placed in a separate vial, properly labeled with the date, num-
t9t2] BROWN—PINUS RIGIDA 389
ber of cutting, and tree, and kept separate from the others in all
the successive processes of fixing and imbedding.
The following year (1910) cuttings were again resumed on the
same trees, as well as on four more in the same row. The manner
of procedure was identical with that above described except
(a) every other cutting was omitted and (b) this season the first
cutting was made February 21, the second April 2, and thereafter
~ until the third of May. The object was to check up the results of
the previous season and to make new observations. Two cuttings
were also made on trees A, B, and C on April 27, one on the north
side and one on the south. For purposes of comparison, one root
cutting was taken from tree III on the same date.
Microscopical characters of the wood
As is characteristic of the Coniferae, the secondary wood of
Pinus rigida is entirely devoid of vessels. It consists almost
entirely of tracheids with bordered pits on their radial walls. In
cross-section these appear regularly arranged in radial rows, which
occasionally divide as they proceed toward the cambium. In
longitudinal section they present the normal tracheid form, that is,
a rectangular prism with sloping ends. The annual rings are
sharply differentiated. Proceeding from the pith outward in
radial direction are numerous pith rays; secondary rays arise in
response to necessity; both are of the usual coniferous type. The
histological characters of coniferous wood, however, have been
described in detail by PENHALLOW (11), and the reader is referred
to his excellent work for further detail.
The structure of the secondary thickening in the roots is quite
closely related to that of the stem. However, there are one or
two differences. The demarcation between the different rings is
not so sharp. This results because the wood of the root is less
dense than that of the stem. The tracheids possess wider lumina
and there is less summer wood produced. In radial section the
bordered pits on the walls are often biseriate, a condition which is
never met with in the wood of the aerial portion.
39° BOTANICAL GAZETTE [NOVEMBER
Microscopical characters of cambium and cortex in winter
condition
CROSS-SECTION
The radial rows of tracheids in the xylem continue directly out
into the cortex (fig. 9) through the cambial zone. For a time this
radial arrangement is maintained, but sooner or later it becomes
irregular, due to certain changes which take place. The cambial »
zone in cross-section appears as a number of layers of cells with
comparatively thin walls. It is impossible to pick out the initial
layer. Exterior to this are the sieve tubes. These have wider
lumina than the cells of the cambial zone, and the walls are thick-
ened as much as or more than those in the summer wood section
of the xylem. However, they are not lignified as are the latter.
Companion cells are wholly lacking. The rows of bast parenchyma
are very prominent. One row with a few scattered individuals is
formed each year (STRASBURGER 13), so that the thickened layers
of sieve tubes are separated by thin bands of bast parenchyma. In
the outer cortex the bast parenchyma cells become gorged with
starch and greatly enlarged. As a result the older sieve areas are
stretched tangentially and are seen as thin bands separating the
larger cells. Pith rays appear as straight lines running out into
the cortex, but as they proceed radially into the cortex they soon
become more or less irregular and curved. There are no crystalloge-
nous cells such as are described by STRASBURGER in Pinus
silvestris. Exterior to the cortex proper there is a series of corky
layers which have arisen from living cells in the outer cortex, the
so-called cork cambiums. Their structure is of the general type
described by STRASBURGER (13).
RADIAL SECTION
In radial section the cambial cells appear as prisms with sloping
ends. The size varies slightly with the age. The sieve tubes have
the general shape of the cambium cells from which they originate-
Their radial walls are equipped with sieve plates, and these have
the same location as the bordered pits on the walls of the tracheids.
In radial section likewise we see to best advantage the bast paren
chyma. This consists of rows of barrel-shaped cells arranged one
1912] BROWN—PINUS RIGIDA 301
above the other. There is also a change in the pith rays. The
ray tracheids have given rise to ray cells, so that the pith rays con-
sist exclusively of the latter. These as well as the bast parenchyma
cells contain abundant starch.
TANGENTIAL SECTION
In order to study cambiurfi and cortex in tangential section, a
series of mounts is necessary. The same general characters are
observable, but in addition it is evident that there is an entire
absence of sieve plates on the tangential walls of the sieve tubes.
The callus thickenings of those on the radial walls, however, are
particularly noticeable with proper staining (methy] blue).
Cambial awakening
In taking up the study of xylem formation as it normally occurs
in trees, one naturally begins the study before cambial activity
begins. Cuttings taken at different heights from tree III on
February 21, 1910, all showed in cross-section the general outline
of the completed ring. Growth was not manifest in any of the
sections. Each ring presented well marked areas of early and late
wood. The latter in Pinus rigida is sharply differentiated, owing
to its greatly thickened walls. The above statement does not hold
true, however, for the wood of the first two or three years at any
point in the trunk. Here there is no sharp demarcation between
early and late wood. This condition is probably brought about
by the fact that the main axis was elongating rapidly at this point
when the ring was formed, or else, as these investigations tend to
show, growth is slow in beginning in the apical shoot but progresses
very fast when once started, so rapidly in fact that there is not
sufficient time for the walls to thicken appreciably. In either
alternative, there is a gradual thickening in the walls of the late
wood of successive rings as the apical shoot progresses aloft.
The next set of cuttings were taken on April 4, 1910, from tree
III. The cambium was still in the resting condition. Figs. 1-3
and 7-9 show the changes which occurred (figs. 1-3) between April
4 and April 15. In fig. 3 growth is more advanced than in either
figs. 1 or 2. The latter are both in the resting condition. So far
392 BOTANICAL GAZETTE [NOVEMBER
as can be detected there is no evidence of tracheal formation.
Figs. 7-9 are from cuttings made on the same individual at this
time, but each successively nearer the ground. In the first two
growth is in evidence, while in the last the cambium is still in the
resting condition. It is evident from the photographs that in the
spring of 1910 growth made itself manifest in tree III as early as
April 15. Cuttings taken from trees IV and V at the same date
likewise showed evidence of cambial activity. While there was no
satisfactory evidence obtained the previous year as regards cambial
awakening, since observations were begun too late, sections from
tree II on May 13, 1910, showed growth in such an advanced state
that cambial activity must have begun fully as early the previous .
year.
As regards cambial awakening in trees A, B, and C, no lengthy
observations were carried on; but two cuttings per tree were made
on April 27, one on the north side and one on the south. At this
date trees B and C already showed evidences of growth at breast
height in both cuttings. In tree A the cambium was still in the
resting condition. However, tree A was older and taller than the
other individuals, and it is very evident that growth must have
already begun in the higher parts.
The observations described above are in accord with those of
other investigators. BitscEen (3) gives the time in general for
cambial awakening for middle Germany as between the last half
of April and the first half of May. R. Haptic (7) has observed
that evidences of growth are manifest in young (10 years) specimens
of Pinus silvestris as early as April 20, while its appearance at the
base of the older trees depended very much on external factors,
such as thickness of stand, soil conditions, ground cover, etc.
Buckuout (2), by means of bark measure, gives the date of growth
inception in larch and white pine as the last week in April. How-
ever, as his computations were made at the base of the trees,
probably growth began aloft earlier. That growth was not vl
denced at the base of tree A was due, according to the researches
of R. Hartic (7), to at least three causes, namely (a) long trunk,
(6) age, and (c) shaded base. While the present investigations do
not afford conclusive evidence, inasmuch as they covered but a
1912] BROWN—PINUS RIGIDA 393
period of two years, it would appear that in the vicinity of Ithaca
growth began in Pinus rigida at about the same time each spring.
To determine this point definitely, however, observations must
needs be carried on for a period of years. That growth made itself
evident in 1910, however, as early as April 15 is readily apparent
from the photographs.
Place of cambial awakening
The question of origin of growth is still in dispute. T. Harric
(8) claimed that it made itself manifest in the youngest branches
first and extended slowly downward. NORDLINGER (Forest Botany,
1874) makes the same assertion. R. Hartic (7) appears to accept
his father’s statement if we are to judge from the following quota-
tion: “Am oberirdischen Stamme beginnt der Zuwachs zuerst in
den jiingsten Trieben,” etc. These three investigators, therefore,
were unanimous in the opinion that the awakening of growth is
earlier at the top of a tree than below.
MER (10) disputes this general assertion. According to his
researches, the procedure of awakening was sensibly different in
older trees. While in 25-year-old oaks, beeches, and firs, growth
was first manifest in the youngest branches, in the older trees it was
in evidence at the same time at the bases of the branches and even
in the trunk where the roots began. From these points growth
gradually extended to the intermediate regions.
Figs. 4-6 correspond respectively to those of the preceding
numbers, except that a, period of 19 days intervened. Comparing
those of different date, we see that growth is more in evidence in
every case where the cutting was taken at the later date. In figs.
1 and 2 we have apparently the resting condition, while figs. 4 and
5 exhibit signs of growth, the latter being more in evidence in fig. 5.
Comparing figs. 3 and 6, it follows that there is a considerable
advance in growth. In the former, at the outside, only two half-
formed tracheids are to be seen, while in the latter three or four
rows are present and these are of larger size. Comparing figs. 1-6
as a whole, it is evident that during a period of 19 days there was
an awakening of cambial activity in the apical portion, first manifest
in fig. 3 on April 15. Growth first appeared in the crown of tree III
3094 BOTANICAL GAZETTE [NOVEMBER
some distance below the apical shoot, but in a period covering 19
days gradually spread upward and was in progress in the apical
shoot on May 4, I1g1o.
Cuttings of May 4 corresponding to figs. 7-9 were not photo-
graphed. Examination revealed the fact, however, that growth
was in progress throughout the basal portion of the trunk on that
date, and had progressed to a greater extent than was evidenced
on April 15.
From the above investigations it follows that growth was in
progress throughout the main axis of the tree on May 4, while 19
days previous it was not in evidence in either the apical portion or
the base. If R. Harric is right in his assertion that growth is first
manifest in the branches, Pinus rigida is surely an exception to the
rule. Mer’s investigations on young trees are in accord with ©
Hartic’s, so here likewise growth in Pinus rigida appears to pre-
sent an anomaly. That Hartic is right in his assertion that cam-
bial activity proceeds from the base of the crown downward,
investigations on trees A, B, and C seem to give convincing evidence.
Cambial activity was already in progress on both sides of the base
in trees B and C on April 27, while both cuttings in tree A on that
date appeared to be in the resting condition. This is explained in
that the trunk of tree B was better illuminated below than that of
tree A, while tree C was but 25 years old. But at this date growth
must have been in evidence in the upper portions of tree A, and
the only reasonable hypothesis is that it had not yet reached the
base, owing to poor insolation, thick bark, and age of the tree.
Growth in lateral branches
With a view of adding something further of value to the manner
of growth procedure in Pinus rigida, investigations were also car-
ried on upon certain of the lateral branches. Cuttings were taken
from each year’s growth until the main axis was reached. Then
incisions were made 20cm. above and a like distance below the
point where the branch joined the main axis. Growth in the
branches followed the same rule as in the main axis. It commences
some distance back of the apical shoot and spreads gradually ”
both directions. Time of awakening in the apical shoots of the
1912] BROWN—PINUS RIGIDA 305
branches, at least in the case of trees standing in the open, appears
to be identical with that in the apical shoot of the main axis.
Cuttings taken May 4 showed about the same amount of growth
in each case.
The time of the beginning of cambial activity at the base of the
branches is of interest when compared with that of the main trunk.
Fig. 11 shows a section from the base of a limb six years old. Fig.
10 is from a cutting taken from the main axis just above the branch,
and fig. 12 a like distance below. Growth is most advanced in
fig. 12, present in fig. 10, but lacking to all appearances in fig. 11.
Cuttings taken from the limb in question showed growth in evidence
to the extent of one or two tracheids (out to and including the
apical shoot). It follows from the above that growth at the base
of the branches is more retarded than at neighboring spots in the
main axis. It proceeds more rapidly in the latter than it does in
the former, so that it is often in evidence in the main axis before it
“makes its appearance at the base of the branches. This may be
due to the more rapid rise of solutions in the trunk, although
further investigation is necessary to decide that point.
Rate of procedure
Having determined the general procedure of growth in Pinus
rigida, observations were next made on the rate of procedure. In
order to make estimates of this, the series of cuttings of 1909 on
tree II were employed. There were four sets of these of twelve
each. In each set the amount of wood formed for the individual
section was determined as nearly as possible with a micrometer
scale, and the results tabulated on a basis of 100 (table I). The
number of days intervening between each observation are given as
well as the total gain and average gain per day; x implies cutting
was a failure; + signifies width at least as much as given; ? indicates
apparent loss due to local growth fluctuation.
The table is of value in leading us to certain general conclusions.
On May 13, the width of the new-formed ring was greatest in cut-
tings 4-6. It gradually dwindled in size toward the apical shoot,
while below there appeared to be a decline followed by an increase.
The next investigation was made on May 25, twelve days later.
396 BOTANICAL GAZETTE [NOVEMBER
TABLE I
No. Gain No. Gain No. Gain,
No. |Amount|Amount| of | Gain Amount! of |Gain} per |Amount} of | Gain bn
days day days day days y
a y June June
13, ’09|29, ’09 3, 09 15, ’09
I 3 Aaa Be ay 5 9| ©] 9.00] 35 | 12 | 30} 2-50
2 3 5 12 216,17 20 irk i x. 08 25+] 12 5 | 0.42
3 8 8: tach -e }-0.00 24 Ce is ou ie 0 x 2) 1s
4| 12 ts | x21. 3.).0.25-|. 40 9 |.45 |} 2.78] 35 | 12): Piece
5 12 10 42") O10. 50 | 30 9 | 12 | 1.33; 40 | 12] 10 | 0.83
6 12 90. 1-39]. 8} 6.67): 30. })-0 | 166} 3.32 35 I2| 5 | 0.42
7 8 Fo [521 5 O42 40 O127-12 40 | 12 | 0.) 9,e0
8 _ 39) 2 ‘| 30 9 | 20| 2.22| 38 | 12| 8 | 0.67
9 8 WL 1 29 1s | as} a0 9 | 29 | 3-22.| 45 | 12| 5) 9-42
Io 6 mY ag} | O.34 | 21 QO | 1%) ¥.93'| 36 3s) °O te
II x ete re] 25 Ye ee x 42 | 12] 17 | 1.42
12 II Wo at Beg x x 9| « x 7 4 32). See
Looking at the average gain per day, we see that in cutting 6 the
greatest increase occurred, while above and below the amount of
gain varied irregularly with the different cuttings. However, the’
gain in the apical shoot was but slight. Comparing the results of
May 25 with those of June 3, it is evident that, with the excep-
tion of the apical shoot, the average daily increase at the latter —
date was greater in every case than in the former. In other words,
the tree grew faster in diameter, with the exception of the terminal
shoot, during the last of May and the first of June than before that
time. It follows from the table that the rate of increase varies
considerably with the cutting and obeys no general law. The
data of June 15, however, are most interesting. There was 4
decrease in the rate of growth between June 3 and June 15, with the
exception of the apical shoot. Here, on the contrary, the gain in
12 days was 15 times as great as that of all the diameter growth
previous to June 3. There was then a very marked increase in the
formation of the annual ring at this point as compared with the
gradual decrease in the remainder of the tree. Unfortunately,
however, data are not available bearing on the rate of elongation ~
of the apical shoot. It would appear, however, that its elongation
must have been very rapid up to June 3, so much so in fact that the
increase in the width of the annual ring could not result. From
June 3 to June 15 the rate of elongation probably decreased appr&
1912] BROWN—PINUS RIGIDA 307
ciably, while greater increase of wood formation resulted as a
natural sequence.
Before summing up the results of the preceding paragraph, some
observation on cessation of cambial activity should be given. It
has long been recognized that while cambial activity makes itself
manifest in many trees at about the same time, there is no relation
evident in its cessation. Thus Buckxuour (2) found in Larix
decidua that there was little if any growth after July, while Pinus
Strobus continued to form wood until well into September. R.
Harrie (6, 7) also gives data bearing on this subject. In beech
it lasts 2.5 months, in oak 4 months, in Scotch pine and Norway
spruce 3 months. FRIEDRICH (see WIELER 14), on the contrary,
claims that in coniferous and hard woods in general there are two
periods of growth, one lasting until about the end of May, sinking
until the middle of June, and reaching a maximum again in July.
Complete cessation resulted by the middle of August. The
majority of workers, however, unite with Hartic in saying that
cessation of’ cambial activity varies greatly with the species con-
cerned.
In the present studies, the latest cuttings in 1909 were made
on July 6 upon tree III. At that time growth was still in progress
throughout. Comparing these with cuttings taken from the same
tree on February 21 of the next year, the following interesting
results are obtained. Cutting 2 showed o.5 of the ring complete,
cutting 4, 0.6, cutting 8, 0.85. R. Harric (6) agrees with T.
Hartic (8) that cessation of growth begins first in the crown in
trees in open stand and proceeds gradually downward. If such is
the case, the data just given present an anomaly, or else growth
Was accelerated in the apical portions after June 15. However
some of Harric’s data are in accordance with that already given.
For example (BUSGEN 3), on June 21 the ring of an oak as compared
to that of a previous year gave the following data:
At. 2.3 mm. Beet. .5.... ©.45 complete
At 2.6m. hewht:.: ..5.; 0.45 complete
0. Tac RE ss ©.45 complete
AL 9.0 m. Deeb: cock: o.72 complete
At 42.3 m. height... ..... 0.57 complete
AC 14.5 mi. height... 5. ©. 56 complete (3-4 year branch)
398 BOTANICAL GAZETTE [NOVEMBER
Hartic then obtained results comparable to the present ones;
that is, at about the middle of June he observed that growth was
most advanced near the middle of the tree and decreased in both
directions from that point. And yet he persists in his assertion
that growth ceases in trees in open stand first in the youngest
branches. Such being the case, the only possible solution of the
data given above is that there must have been a marked accelera-
tion of growth in the apical portions after June 21 and a corre-
sponding decrease in the parts below. Whether the same applies
in the pitch pine further investigation must decide. There was an
increase in radial growth in the apical shoot and at the same time
a decrease below between June 3 and 1s, but that growth ceased
first above cannot be deduced from the present observations.
As regards the theory advanced by FRIEDRICH concerning two
periods of maximum growth in trees, little can be said. The
second period if present in Pinus rigida must be the minor one,
inasmuch as the ring was on an average more than half completed
on June 15.
Width of the ring
Measurements were made from sections of tree III to determine
the width of the ring at different heights. According to HartIG,
in trees in open stand the amount of wood formed increases from
apex to base. This may arise from one of two alternatives; either
the annual ring may decrease in size owing to the increasing diame-
ter, or the reverse may be true. The latter, he says, is but rarely
the case and sometimes occurs in trees which are exceptionally well
nourished, that is, those possessing a large vigorous crown. From
these observations it is to be expected that in Pinus rigida the ring
would increase perceptibly in width toward the base, inasmuch as
the crown is as a rule not exceptionally well developed. Such was
the case. At cuttings 1 and 4, the completed ring on February 21,
1910, was about the same width. At cutting 8 it was but 0.85 the
size of that above, while cutting 12 showed a still further decrease
too.7o. It follows that in Pinus rigida, if there is such a decrease
in the size of the ring from apex downward in young vigorous
growing trees, the same applies with even greater force in older
trees with longer axis and poorly developed crown.
1912] BROWN—PINUS RIGIDA 399
The living portion of the cortex, on the contrary, follows a law
exactly the reverse. In the upper portions of the crown the cortex
is necessarily thin, inasmuch as it contains a relatively small series
of bast parenchyma and sieve tube areas. Below, the thickness of
_ the cortex increases markedly, so much so in fact that it often
attains 3-5 cm. in width. The storing capacity of the cortex as a
result must be greatest in the basal portions of the trunk. Assum-
ing that food abundance alone was concerned in cambial awakening,
the latter would result first below. Inasmuch as it does not, there
are certainly other sigteteeese factors, chief among which is
probably insolation.
Investigations on the older trees revealed a number of factors
of sufficient interest to demand mention in this paper. A curious
feature long known to former workers was especially prevalent.
I refer to the often noted lessened density of the wood on the south
side of trees. This is due to the fact that the proportion of summer
wood on the north side is greater as compared with the width of
the ring than on the south side. This disparity in wood formation,
however, is not so marked in young individuals. The ring forma-
tion is much more regular and it is only in the older trees that the
Phenomenon above described is seen. As to the cause of this
lessened density on the south side, no reasonable conclusion was
attained in these investigations, nor has it ever been satisfactorily
accounted for. It is without doubt correlated with insolation in
some way, but further study is necessary to determine this defi-
nitely.
The manner of cambial awakening likewise presents an interest-
ing study. It was observed that even on different sides of the same
section a noticeable disparity often occurred. In some cases
growth had proceeded to the extent of one or two partly formed
tracheids, while in closely neighboring spots the cambium appeared
as yet in the resting condition. Nor was one tracheid completely
formed as to size before another began. Often rows of three or
four small tracheids were visible, none of which had yet attained
half the size of those formed first the previous year. In such cases
it would appear that cell division was so rapid in the cambial region
during favorable seasons that new elements were laid down before
400 BOTANICAL GAZETTE [NOVEMBER
their predecessors had yet attained their maximum size and
strength.
Double rings were often in evidence in the old trees. These
might easily cause miscalculation as to age. The phenomenon of
double ring formation has often been observed, especially in broad-
leaved trees. Here it was ascribed sometimes to partial or com-
plete defoliation, at others to favorable or unfavorable external
factors. The first assumption would not hold in Pinus rigida in
this case or in general, since defoliation rarely occurs. The cause
must be ascribed to external growth conditions, but what these are
would be difficult to determine. That they are most prevalent in
old trees is well known, and this would lead one to infer that their
formation is in some manner correlated with inhibition of growth,
since the effects of this are most marked on older less vigorous
individuals.
Secondary thickening in the roots
Little stress was put on the study of secondary root thickening
in the present investigation. Only one cutting was taken, on
April 27, 1910, for purposes of comparison, so that no reliable
deductions can be made. At this time cambial activity was not
manifest, although it must have been in process throughout the
aerial portion with the possible exception of the apical shoot.
T. Hartic (8) claimed that cambial awakening in the roots 1S
much later than in the aerial portions. He gave midsummer 4s
the time of first inception and said it continued far into October.
Whether the same applies to Pinus rigida further investigation only
can decide. Suffice it to say, however, that the growth in thickness
of roots must not be confused with growth in length. The latter
is manifest often as early as March and continues throughout the
season.
Summary {2
1. The histological characters of Pinus rigida present no wide
variation from the normal coniferous type. ;
2. The secondary thickening in the root is similar to that 1n
the stem, but differs (a) in less sharp demarcation between the
annual rings, (b) in the biseriate character of tracheids, and (c) im
less density.
1912] BROWN—PINUS RIGIDA 401
3. Growth began in young 20-30-year old specimens of Pinus
rigida in the vicinity of Ithaca as early as April 15. While there
was no direct evidence of cambial awakening secured the previous
year, sections taken at a later date showed growth in such an
advanced state that it must have begun fully as early.
4. In older trees cambial awakening is sometimes retarded at
the base where proper insolation is lacking.
5. There is no appreciable difference in the time of combial
awakening on the north and south sides of trees.
6. Growth began first in 20-25-year-old specimens at some dis-
tance below the apical shoot, but during a period of 19 days
gradually spread upward until it reached the apex of the trees.
7. Investigations on trees A, B, and C tend to show that growth
in older individuals begins first in the crown and spreads downward.
The time of its inception at the base varies with conditions of
insolation, bark, etc.
8. Growth in the branches follows the same rule as in the main
axis. The time of awakening in the former is almost if not abso-
lutely identical with that in the latter.
9. Growth spreads down the main axis faster than it does along
the lateral shoots.
10. Except in the terminal shoot, growth in diameter was more
rapid between May 25 and June 6. In the terminal shoot itself
greatest rapidity of growth was manifested between June 6 and
June 15.
11. No reliable deductions concerning cessation of cambia]
activity can be drawn from the present investigations.
12. The width of the complete ring decreases from apex to base;
the living portion of the cortex follows the reverse rule. :
13. A number of peculiarities already noted by others are preva-
lent in mature specimens. These are (a) lessened density of wood
on the south side of trees, (0) irregularity of cambial awakening in
closely neighboring parts of the same section, (c) successive forma-
tion of new elements before previous ones have reached their
maximum size, and (d) double rings.
CoRNELL UNIVERSITY
Irnaca, N.Y.
402 BOTANICAL GAZETTE [NOVEMBER
LITERATURE CITED
1. Britton, N. L., North American trees. 1908. p. 3
%. ri Ie H, Formation of annual rings of ak Forest Quarterly
5+ 259.
cousin, M. Bau und as unserer Waldbaéume. 1897. p. 62.
CouLtTerR, J. M., and CHAMBERLAIN, C. J., Seed plants. 1901.
Gorr, E. S., The resumption of root growth in spring. Wis. Sta. Rept.
1898: 220-228. fig. 6. 1808.
Hartic, R., Das Holz der deutschen Nadelwaldbaéume. 1885. p. 35-
; Anatomie und Physiologie der Pflanzen. 1891. p. 262.
8. Hartic,:T., Bot. Zeit. 18:829. 1858.
9. Hastines, G. T., When increase in thickness begins in trees. Science, N.S.
123585. 1900.
10. Mer, E., Sur les causes de variation de la densité des bois. Bull. Soc.
Bot. France 39:95. 1892.
11. PENHALLOw, D. P., Anatomy of the North American Coniferales with
certain exotic species from Japan and Australia. Amer. Nat. 38: 243. 1904.
12. Reuss, H., Beitr. zur Wachstumsthitigkeit des Baumes nach praktischen
Beobachtungsdaten des laufenden Starkenzuwachsganges an der Sommer-
de. Forstlich. Zeitschr. 2:145. 1893.
13. STRASBURGER, E., Die Angiospermen und die Gymnospermen. 18
14. WIELER, A., Uber die Periodizitét im Dickenwachstum des rua ai
der Baume. Bot. Zeit. 56:262. 1808.
be gk
ao
5
EXPLANATION OF PLATES XXIV AND XXV
Fic. 1.—Cutting taken from shoot of tree IIL April 15, 1910)
cambium in the resting condition;
Fic. 2.—Same, but cutting eae sas 1m. from the apex; cambium in
the resting condition; 50
IG. 3.—Same, but cutting taken about 2m. from the apex; api es
evidence =f the extent of one or two partly formed tracheids; X 5°
Fic. 4.—Cutting taken from apical shoot of tree III May 4, 1910; growth
just beginning at A; compare with fig. 1; X50.
Fic. 5.—Same, but cutting taken 1m. from the apex; growth slightly
more advanced; compare with fig. 2; Xso.
Fic. 6.—Same, but cutting isken from the i growth in evidence to
the anda of 3 or 4 tracheids; compare with fig. 3
Fic. 7.—Cutting taken from tree III April 15, sik shock 3 m. from oe
apex; growth in evidence to the extent of one or two partly formed tracheids;
X 50.
Fic. 8.—Same, but cutting taken about 4m. from the apex; aes es
evidence to about the same extent as in fig. 7; X50.
PLATE XXIV
BOTANICAL GAZETTE, LIV
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Y on PINUS RIGIDA
PLATE XXV
BOTANICAL GAZETTE, LIV
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12
BROWN on PINUS RIGIDA
Il
1912] | BROWN—PINUS RIGIDA | 403
Fic. 9.—Same, but cutting taken about 5 m. from the apex; cambium in
the resting condition; X50.
IG. 10.—Cutting from main axis of tree VI April 22, 1910, at a distance
of 3m. from the apex; growth in evidence to the extent of several rows of
partially formed tracheids; X 50.
IG. 11.—Same, but cutting from the base of a lateral branch which
entered the main axis 20 cm. below cutting shown in fig. 10; no growth in
evidence; X 50.
IG. 12.—Same, but cutting taken 40 cm. below that in fig. 10; growth
in evidence to the extent of several rows of tracheids; X 50.
CONTRIBUTIONS FROM THE ROCKY MOUNTAIN
HERBARIUM. XII
NEW PLANTS FROM IDAHO
AVEN NELSON
In this paper are continued the studies upon the plants of south-
ern and western Idaho, begun in no. IX of this series of Contri-
butions. As stated in the preceding paper, the present studies
are based upon collections made in 1911, largely by Mr. J. FRANCIS
Macsripg, but assisted in the field for a time by the writer. There
are also included in this paper a few species based upon collections
made by Miss June A. Cxark, of Boise, at present a student in
the Idaho State University. During 1911 she made very credit-
able collections of the plants of the mountains adjacent to Boise,
and in the mountains of Washington County of her state.
Melica Macbridei V. H. Rowland, n. sp.—A green slender erect
tufted perennial, 2-5 dm. high, growing from bulbs, which may be
solitary or in clusters of 2-6: culms and sheaths (which exceed
the internodes) hispid-scabrous on the prominent nerves: leaves
exceeding the sheaths in length, usually 3 in number, the basal
withering early, flat, thin, and weakly ascending, 1-4 mm. wide:
panicle loosely open; rachis decreasingly scabrous toward the
apex, with 3-9 nodes, the first internode 3.5—5 cm. long: rays
1-3 at each node of the rachis, if 3, the first subsessile, the second
on a short pedicel, the third on a long capillary reflexed pedicel:
spikelets 2~5-flowered, 7-13 mm. long, with terminal flower sterile,
never flattened: glumes unequal, herbaceous, scarious-margined,
quite often purple-tipped, oblong, acute; the first 4 mm. long,
3-nerved. and about two-thirds as long as the second; the second
5-nerved, 6mm. long: lemma thicker than and about equaling
the second glume, lightly scabrous throughout, obtusely bifid:
palet reaching to the notch in the lemma, 2-keeled, spathe-shaped
with the lower part inclosing the white wormlike rachilla, ciliate
on the keels from near the middle to the apex: fruit cylindrical
with the divergent styles sometimes persistent.
Botanical Gazette, vol. 54] [404
1912] NELSON—IDAHO PLANTS 40
5
‘ This species is nearest to Melica bromoides Gray, from which it differs as
follows: M. Macbridei is about one-half as high as M. bromoides and much
slenderer and more graceful in appearance; it is much more scabrous and the
roughness continues beneath the sheaths to very near the nodes of the culm;
the sheaths exceed the internodes; the floral parts are shorter and wider than
in M. bromoides; the nerves of the glumes and lemmas never extend to the
margins; ne lastly the rachilla between the flowers is smooth, white, and
wormlike” and never green as in the other.
This is ee 948 of Macsripe’s 1o11 collection of Idaho plants, secured
on dry slopes at Silver City, June 20.
Calochortus umbellatus, n. sp.—Bulb small, ovoid to sub-
globose: stems slender, 3-5 dm. high, 2—3-leaved; lower leaf long,
4-8 mm. wide, from one-half to three-fourths as long as the stem;
the other leaves narrowly linear (if only one, near the middle),
5-10 cm. long: flowers 3-9, in an umbel; pedicels slender, erect
(in a fascicle), 5-1o cm. long; involucral bracts few-several, 2-4
cm. long, the ovate base scarious, abruptly narrowed to the long
filiform green acumination: sepals lanceolate, acuminate, one
margin more broadly scarious than the other, 25 mm. or less long:
petals obovate-cuneate, the rounded summit more or less erose
and abruptly apiculate or subacute, white, with an indigo or purple
spot near the middle; the gland small, round, yellow, short-setose,
some long soft filamentous hairs scattered over the lower half of
the petal: filaments not much if any longer than the anthers,
dilating gradually from apex to base: capsule ellipsoidal, about
15 mm. long, narrowly thin-winged, lightly transversely striate.
There is no doubt that this has passed as C. nitidus Dougl., to which it is
closely related. The Idaho specimens seen by the writer cannot, however,
well be so referred. Purpy has recharacterized C. nitidus in his excellent
revision (Proc. Cal. Acad. Sci. III. 2:128. 1901) and the following facts,
- drawn from his description are in direct contrast with C. uwmbellatus: “Stems
bulb-bearing near base, not bracted in the middle”; ‘“‘umbel of 2-4 flowers
subtended by 2-4 linear bracts”; “sepals ovate-lanceolate, exceeding the petals’’;
“petals 2 inches long, the same in width”; “filaments filiform, winged below”’;
capsule strongly winged and crested.”
NELSON and MAcBRIDE’s no. 1197, July 19, 1911, is taken as the type.
The species seemed quite abundant on sagebrush lands near Wood River at
Ketchum. Mr. C. N. Woops has also secured it (no. 258) in the same county
(Blaine). A specimen from Yellowstone Park by Mrs. E. W. SCHEUBER is
also referable here.
406 BOTANICAL GAZETTE [NOVEMBER
Zygadenus salinus, n. sp.—Bulbs globose, or even depressed
globose, not deep-set (4-8 cm.), 1-3 cm. in diameter; outer bulb-
coats brown, thin, and fragile; the next succeeding ones delicately
thin-scarious, glistening white: leaves green, grasslike, usually
folded, scabrous on the margins, somewhat pruinose, especially
on the greenish sheaths, 7-12 mm. broad, shorter than the scapose
stems: stems slender, erect, 3-6 dm. high, with 2-3 non-sheathing
linear leaves: raceme short, rather crowded; the pedicels slender,
becoming 2-3 cm. long; the bracts with short ovate base and very
long linear acumination, the lower as long as or longer than the
pedicels: flowers in a simple raceme, yellowish-white; perianth
segments nearly similar, 3-7-nerved, all clawed; the sepals with
very short claw, ovate, obtuse; the petals elliptic, obtuse, with
evident claw which is more or less concave or inrolled; the glands
in both small, inconspicuous, and confined almost wholly to the
upper part of the claw: stamens surpassing the perianth, on fila-
ments only slightly dilated below: ovary free from the calyx;
the styles 2-3 mm. long: fruit ovate, about 6 mm. long; the cells
united to the summit.
I should hesitate to describe this as a new species were it not for the glo-
bose bulbs and the habitat. The near allies are Z. venenosus Wats. and Z.
intermedius Rydb. These have elongated bulbs; the former has conspicuous
glands, and the latter has all the leaves with scarious sheathing base. Both
have deep-set bulbs, and belong to dry non-saline soil, while the proposed
species was secured in alkali-bog lands, with the bulb but a few centimeters
below the surface. It seems that typical Z. venenosus is confined to the coast
a (see Prrer’s Fl. Wash. 198, and BLANKINsHIP, Mont. Science Studies
4:45).
Type no. 889, MAcBRIDE, Emmett, June 9, r91t.
Salix boiseana, n. sp.—A low shrub, forming clumps, 1-2 ™- —
high: twigs glabrous, reddish brown or chestnut, slightly shining
or obscurely glaucous: leaves oblong, either obtuse or subacute at
apex, usually cuneately narrowed at base, 2-4 cm. long, minutely
pubescent but green above, pale with a fine tomentum beneath,
margin quite entire; stipules wanting: pistillate aments with two
or three foliar bracts at base, 3-5 cm. long: floral bracts (scales)
small, ovate, obtuse and brown, about half as long as the pedicels,
long silky hairy below, especially near the apex and margin, gla-
1912] NELSON—IDAHO PLANTS 407
brate above: pedicels slender, 1.5-2 mm. long; capsules glabrous,
3-4 mm. long: style evident but very short (less than 0.5 mm.).
This is most nearly allied to S. Wolfit Bebb, but seems to be distinct by
the cuneate base of the leaves, which are glabrous or nearly so above, tomentose
on the lower face (not silky-villous with shining hairs on both sides), by the
longer pedicels, the slenderly virgate fertile stems (S. Wolfii_is freely short-
branched), and the longer fertile aments. S. boiseana belongs to lower alti-
tudes and matures much earlier in the season.
Miss JUNE CLarK secured the type material (no. 48) in overripe condition,
May 29, 1911, near Boise at an altitude of less than 3000 feet.
Eriogonum fasciculifolium, n. sp.—The shrubby base low
(1-2 dm.) and somewhat di- or trichotomously branched; the more
or less scaly bark dark brown or dirty black: leaves fasciculate or
verticillate on the enlarged nodes, mostly on the crownlike apex
of the branchlets, linear or narrowly oblanceolate, 1-3 cm. long,
tapering to a short petiole, rather thick, pale-green, glabrate above,
obscurely tomentose below: peduncles from the upper nodes or
terminal, 4-8 cm. long, bearing a few-rayed umbel, lightly pubes-
cent; the bracts foliar, apparently always few (2-4), or sometimes
wanting: rays 12-20 mm. long: involucre many-flowered, campanu-
late, its ovate-oblong reflexed lobes as long as the tube, sparsely
silky-villous: flowers pale yellowish-white, rather large: sepals
similar, broadly obovate, about 5 mm. long, lightly silky-villous
below and on the pedicel to the joint: filaments pubescent below,
much shorter than the triangular glabrous achene.
This new member of § PsEupDO-UMBELLATA is at once distinguished by its
branched shrubby base and its very narrow leaves, though it has all of sd
characteristics of the section.
A limited quantity only was secured by Miss JUNE CLARK at Pineak
Washington County, Idaho, August 12, 1911, no. 236, on a dry mountain side.
Stellaria (ALSINE) praecox, n. sp.—A diminutive vernal species
of arid districts: stems usually simple but sometimes branched
from the base, glabrous except for some crisped hairs on the lower
internodes, 7-15 cm. high (including the long filiform pedicels):
leaves few, mostly in a basal rosette, with 1 or 2 pairs on the lower
part of the nearly filiform stem, narrowly lance-linear, 5-12 mm.
long: cyme unequally 3-rayed, some of the rays again unequally
trichotomous; the bracts minute, somewhat scarious: sepals
'
408 BOTANICAL GAZETTE [NOVEMBER
lanceolate, scarious-margined, about 3-5 mm. long: petals wanting:
stamens 5, opposite the sepals and less than half as long: stigmas
3, nearly sessile: capsule ellipsoidal, each of its 3 valves 2-toothed,
shorter than the calyx; seeds several.
Some of its characters are suggestive of S. umbellata Turcz. (Alsine bai-
calensis Coville). That also is apetalous and has five stamens, but in it they
alternate with the sepals. The capsule is oblong-ovoid and twice as long as the
sepals. The seeds in the two seem nearly identical, with an almost annular
embryo. The aspect of the two species of course is wholly different, S. prae-
cox looking more like a very slender S. longipes Goldie.
The plant has added interest because many of the scarcely distorted cap-
sules were found to be filled with a smut which Dr. CLINTON pronounces as
new also, and to which he has given the name Ustilago Stellariae.
Macsrive secured this at Falk’s Store, Canyon County, Idaho, on moist
slopes, under sagebrush, no. 763, April 24, 1911.
Crataegus tennowana, n. sp.—Small treelike shrubs, 3-0 m.
high, sometimes growing in clumps and then lower and less tree-
like: trunk short, usually less than 1dm. in diameter: spines
straight, nearly at right angles, lustrous reddish-brown becoming
grayish, about 15 mm. long (1-2 cm.): leaves mostly oval (varying
to suborbicular) in general outline, both base and apex with rounded
contour, often however cuneately narrowed below and more
rarely above as well; the upper half from shallowly to deeply and
irregularly serrate, the teeth with more or fewer gland-tipped ser-
tulations; the lower half glandular serrulate or with a few sessile
glands on the entire margins (occasionally the glands extend down
upon the petiole which is only 2-10 mm. long); pubescence want-
ing from the first upon the petioles and on the underside of the
leaves, sparsely and minutely hirsute on the upper side, especially
along the veins, from the first to maturity; the veins of the rather
thin leaves somewhat superficial on the lower side, the midrib
flattened and narrowly wing-margined, at least in the young
leaves: corymb wholly glabrous except for a slight pubescence
on the inner face of the calyx lobes, 5—15-flowered, with scattering
glands on the peduncle and pedicels and very rarely on the tri-
angular-lanceolate persistent calyx lobes: stamens seemingly 8
when the styles and carpels are 4, and 10 when the styles and
1912] NELSON—IDAHO PLANTS 409
carpels are 5 (the more unusual number); anthers pink: fruit
black or purplish-black, maturing in July: carpels with rounded
back, cuneately narrowed to the somewhat sulcate ventral angle,
not narrowed at base.
This may be thought too near C. Douglasii Lindl., but authors are fairly
well agreed that that species should have the following characters, to none of
which this seems to attain:
ee size (30-40 feet high, with trunk sometimes as much as 20 inches in
above, on the veins below, and on the petioles when young: calyx lobes decidu-
ous, glandular serrate: stamens 20 (SARGENT), 10-20 (BRITTON, ROBINSON,
and FERNALD, ef al.): anthers yellow: styles surrounded at the base with long
pale hairs: fruit ripening in August and September: carpels narrowed at base.
In view of the differences indicated it would seem that at least some of the
western forms that have heretofore passed as C. Douglasii need to be separated
from it.
The type is MAcBRIDE’s no. 799 (flowers, May 10; ripe fruit, from naked
tree, July 8), moist woods, Falk’s Store, Canyon County.
Trifolium tropicum, n. sp.—Apparently green and glabrous
but under a lens pubescent with scattering white hairs, especially
near the midrib both above and below: stems single, from slender
rootstocks, erect, slender, 2-3 dm. high: leaflets linear, 3-6 cm.
. long, 2-5 mm. wide, minutely denticulate by the projection of the
beautifully arcuate nerves; petioles slender, from much shorter
to much longer than the leaflets; stipules linear, the free portion
usually denticulate, 14-18 mm. long, either shorter or longer than
the adnate portions: heads about 2cm. high, nearly as broad,
solitary or 1 or 2 smaller ones from the upper leaf-axils, in bud
silvery-silky with the long abundant hairs on the filiform calyx
lobes: flowers purple to rose-red, soon reflexed and nearly con-
cealing the pubescence of the calyx: calyx lobes longer than the
thin scarious glabrate tube: standard oblong, with rounded apicu-
late apex, about 10mm. long and 4mm. broad when spread out
flat; wings as long as the standard, the blade narrowly oblong,
conspicuously auricled at base, as long as the slender claw; keel
petals semi-oval, shorter than the wings, the claw longer than the
blade: style a little longer than the stamens: ovary glabrous, about
8-ovuled.
41c BOTANICAL GAZETTE [NOVEMBER
Most nearly allied to T. Harneyensis Howell, from which it is at once
separated by its pubescent leaves, sessile flowers (which are early, not tardily,
reflexed), and glabrous calyx tube and ovary.
MAcsRIDE’s no. 967, from Jordan Valley, Owyhee County, in moist loam
soil, June 22, 1911, is the type.
Lupinus tenuispicus, n. sp.—Silvery-silky, with loose, copious,
somewhat spreading and tangled hairs: perennial, in dense clumps
on a woody caudex, 3-7 dm. high: stems rather slender, sparingly
branched: radical leaves on slender petioles 1-2 dm. long; leaflets
6-9, narrowly oblanceolate or nearly linear, 4-6 cm. long; cauline
leaves similar, shorter-petioled and (above) sessile: spikes slender,
_ crowded, 5-15 cm. long: bracts small, linear-lanceolate, somewhat
shorter than the nearly sessile calyx: calyx barely gibbous at base,
about 5mm. long: flowers blue: standard nearly orbicular, the
blade pubescent on the back with fine long hairs (only visible
under a good lens), 6-8 mm. long, sharply emarginate at apex;
wing petals oval, on very short claws; keel petals small and deli-
cate, the blade semi-ovate, on a claw half as long: pods very short,
1~3-seeded, pubescence as on the rest of the plant.
I can find no described species in this range having the very slender and
crowded spikes, the small apparently glabrous petals, and the short few-seeded
(often only one) pods of this form.
No. 203, by Miss June Crark, from Tamarack, in the mountains of
Washington County, Idaho, August 8, rrr, is the type.
Astragalus nudisiliquus, n. sp.—Habit and appearance of
A. utahensis T. & G., the white indument even thicker and more
felted: caudex woody and freely branched: pod about 20 mm.
long, probably at first white woolly-hirsute, the indument at length
deciduous and disclosing the longitudinal striae, coriaceous-woody,
ovoid, flattened dorsally, the acute apex abruptly flexed, the dorsal
suture slightly keeled, the ventral somewhat sulcate.
When the writer collected this and first examined it later, he took it for
granted that it was merely an over mature A. ulahensis. On noting the chat-
acter of the pod, however, it is evident that this is not the case. In that species
the indument is permanent, both sutures are inflexed, the body of the pod 3s
smaller, the apex is essentially straight, and, as a more strikingly character-
istic difference, the striae are transverse. In view of these facts it seems best
to put this species (which has no doubt passed for A. utahensis) on record.
1912] NELSON—IDAHO PLANTS 4II
Secured by NELSON and MAcBRIDE on the steep cobblestone bluffs of the
Snake River, at King Hill, Idaho, July 15, 1911, no 1088.
Astragalus obfalcatus, n. sp.—The woody taproot vertical,
with an enlarged crown, or in older plants with closely branched
caudex, the branches with enlarged crowns: stems solitary or few
from the crown or crowns, stoutish, erect, coarsely striate, green
and glabrate or sparsely hirsute with white hairs, few-leaved, 1-3
dm. high: leaves crowded on the crowns, somewhat spreading
upon the nearly erect petioles (the dead petioles persisting),
canescent with straight stiffish widely spreading coarse hairs;
leaflets 7-13, from oblong (or spatulate) to elliptic or obovate,
10-20 mm. long; petioles 5-10 cm. long, those of the stem shorter:
peduncles axillary, few-flowered: calyx tube 5-7 mm. long, the
pubescence on it mostly finer and shorter, black in part, its linear
lobes nearly as long as its tube: bracts linear, rarely as long as the
calyx tube: pods widely divaricate, falcate upward, abruptly
long-cuspidate, canescent with coarse hairs, completely 2-celled
by the intrusion of the dorsal suture, the rounded back scarcely
sulcate, somewhat flattened laterally to the almost carinate ventral
edge, the stout stipe not as long as the calyx tube: seeds many.
In habit this species suggests A. mollissimus Torr. The shape of the leaf-
lets and even the pubescence is somewhat similar, and the pod is 2-celled, but
there the similarity ends. There are a few other species in which the pods
are falcate upward, but A. obfalcatus approaches none of these as closely as it
does A. mollissimus. |
Secured by MacsBripE (no. 1023) in dry lava soil, on Reynolds Creek, in.
Owyhee County, July 3, ro1z (full fruit; flowers not seen), and by NELSON
and MAcBRIDE (no. 1119), at King Hill, in loose lava cinders, July 15, rorr.
Lathyrus Bradfieldianus, n. sp.—Glabrous, mostly less than
1m. high, stems weakly erect, among undershrub which give par-
tial support, rather strongly striate but noticeably angled only
on the more or less branched upper portion: leaflets mostly 10,
subsessile, beautifully and rather strongly veined, bright green
above, scarcely paler beneath, from broadly elliptic and obtuse
(or even retuse) to narrowly ovate and acute, all subulate-tipped,
15-30 mm. long; tendrils well developed, somewhat branched;
rachis moderately stout, the petiolar part usually shorter than the
412 BOTANICAL GAZETTE [NOVEMBER
_internodes; stipules large, consisting of a triangular-lanceolate
upper portion (which is entire and acute, or somewhat acuminate)
and a much larger somewhat reniformly expanded basal part
(which is usually coarsely and irregularly 3-5-toothed): flowers
large, 3-8, closely approximated at the end of the long (10-15 cm.)
axillary peduncles: calyx very oblique, the lanceolate teeth small,
each shorter than the part of the tube to which it is attached,
except the lower one which is linear and nearly as long as the tube:
petals dark blue or purplish, lighter toward the base; the claw of
the standard rather broad, sulcately folded and with conspicuous
winglike crests at junction with abruptly flexed or reflexed reniform
or orbicular emarginate blade; wings broadly elliptic, on a very
slender claw shorter than the blade: pods nearly straight, 5~6 cm.
or more long, 6-8 mm. broad, about 15-ovuled.
Resembling and related to L. pauciflorus Fernald, Bot. Gaz. 192335, 1894;
from which it is readily distinguished by its broad obtuse lower leaflets, its
stipules with their remarkably expanded bases, its more numerous and larger
and broader flowers, and always by the conspicuous rounded crownlike crests
at the summit of the folded claw.
MacsrIDE’s no. 927, from Silver City, on brush covered hills, June 19,
tg1t, is the type. Mr. Wittiam C. Cusicx’s no. 2538, from mountains near
North Pine Creek, Oregon, is to be referred here, as well as Miss CLARK’S no.
85, from Boise (Clear Creek), July 4, 1911. The species is named in honor of
Mr. A. D. BRrapFIELD, superintendent of the Silver City schools, an appre-
ciative student of his local flora, who spent much time in the field assisting
r. MACBRIDE.
Viola Clarkae, n. sp.—Perennial from a woody sub-horizontal
rather long rootstock, which bears a simple or branched caudex:
branches of the caudex 1-4 cm. long, brown, and rough with the
old petiolar bases: new plants often arising from the nodes of the
rootstock at intervals of 2-5 cm.: herbage glabrous: stemless, OF
stems long (2-3 dm.), weak and procumbent and bearing several
normal leaves: leaves mostly on the crowns of the caudex, crowded;
the petioles very slender, 3-10 cm. long; the blade ovate, 2-5 cm.
long, tapering rather gradually from near the base to the obtusish
apex, the base roundish and shallowly cordate, the margin obscurely
crenate and smooth; stipules greenish, linear, with few-many
filiform pinnately arranged lobes or teeth: peduncles filiform, about
1912] NELSON—IDAHO PLANTS 413
as long as the petioles, or if borne on the stems nearly as long as
the whole of the subtending leaf: flowers (at least the late ones)
rather small, blue: sepals lance-linear, less than half as long as the
petals: lateral petals broadly spatulate, about 1 cm. long, a circular
spot near one margin (toward the base) covered with rather long
stiff white hairs; lower petals obovate, emarginate, 15-18 mm.
long (including the straight spur with its abruptly bent acute
tip): stigma obscurely pubescent: capsule smooth: seeds brown,
with a pale conspicuous strophiole-like attachment.
There seems to be no near relative of this among the western species of
lola
I have pleasure in dedicating this apparently strong species to Miss JUNE
CiarK, of Boise, Idaho, who made an extensive collection of the plants, in
duplicate, in her home neighborhood and in the mountains of Washington -
County, during the season of 1911. Her no. 84, from Clear Creek, in the Boise
Mountains, July 4, rorr, is the type.
CHRYSOTHAMNUS OREOPHILUS artus, n. var.—Difiering from
the species in the stricter, narrowly racemose panicle, the filiform
semi-cylindrical leaves, and the more glutinous involucres.
Secured by Miss Crark, near Boise, September 1, rg11, no. 317. Col-
lected also by HENDERSON at Nampa, July 30, 1897, and by Cusick in East-
ern Oregon, September 7, 1900, no. 2503. Distributed by them as an unnamed
variety of C. graveolens.
CHRYSOTHAMNUS PUMILUS Iatus, n. var.—Distinguished from
the species by the thin, flat, broad leaves (5-8 mm. wide) and the
small cymose corymbs.
Were one to see just the herbage of this plant, it might readily be mistaken
for some Chrysopsis.
NELSON and Macsripe’s no. 1236, Ketchum, Idaho, July 20, ro11, is
typical. Certain numbers by other collectors seem to be more or less
intermediate
Guess FILIFOLIUS Bloomeri, n. comb.—£. Bloomeri Gray,
Proc. Am. Acad. 6:540. 1865; E. fissuricola A. Nels. in Herb.—
Perhaps no better example has been afforded of that form of error
which comes from founding a species upon a single collection, or
€ven upon several, when those represent a mere fraction of the range
of the plant as it later comes to be known, than is supplied by what
we now know of E. filifolius and its near allies. Whether
414 BOTANICAL GAZETTE [NOVEMBER
liability of making a mistake, because of lack of knowledge of the
variability and range of the plant in hand, is so grave a matter
that one ought to be deterred altogether from founding a species
upon a single collection may well be questioned. No doubt there
are those who would take the affirmative, but general adherence
to such a practice is manifestly impossible and probably also unde-
sirable. To begin with, it would bar out the amateurs and ama-
teurs are the stuff out of which professionals (experts) are made.
It would defer publication of even the best of species, often indefi-
nitely, and that is to kill interest and delay development. There
would be little incentive to make collections were it understood
that some one in the next generation would make report upon all
_ except the well known things. That it is desirable to avoid the
making of useless synonyms cannot be too strongly emphasized,
but even a few synonyms is to be preferred to stagnation and death.
Nevertheless, such an array as the following ought to secure
renewed caution in the best of us and deep penitence in the worst
ofus. Those who lament (and that includes the “chiefest sinners”)
are prone to think that great facility (perhaps agility) in making
synonyms is peculiar to the present generation. Let us see how
these examples (scores of others, just as illuminating might be
found) bear out that idea. oe
Douctas collected two plants in the region of the Columbia
which were described in HooKer’s Flora (2:20. 1834) as Diplo-
pappus filifolius and D. linearis. The first of these NUTTALL trans-
ferred, and it became Erigeron filifolius (Trans. Am. Phil. Soc.
72328. 1841), although he probably did not himself know the plant,
since the canescent paniculately branched stems and the yellow
flowers mentioned by him do not belong together. In the mean-
time DECANDOLLE had based another name upon the same Doug-
lasian collection, viz. Chrysopsis canescens (Prodr. 53328. 1836),
and in spite of the fact that he speaks of the flowers as yellow, the
chances are that this name refers to Diplopappus linearis, at least
in part, just as Nurratt’s name does. In the Torrey and GRAY
Flora (2:177. 1842) this difficulty is not cleared up, but the true
facts are suggested, in part, while they are also obscured by the
retention of Nurtatt’s E. ochroleucum (loc. cit.), to which HooKERr’s
1912] NELSON—IDAHO PLANTS 415
D. linearis is referred. Following this, apparently not much is
gained by the publication of E. pumilus Hook. (Lond. Journ. Bot.
6:242), nor the new combination (E. canescens Parry [Jones Exp.],
no. 239), for Gray refers both of these also to E. ochroleucum.
Gray in the Synoptical Flora (1:213. 1884) continues the con-
fusion that had been increased by the publication of E. peucephyllus
(Proc. Am. Acad. 16:89. 1880), in which characters belonging in
part to both of HooKER’s species are combined.
These facts have been recited merely to show the impossibility
of foreseeing the degree of variation or even the direction in which
it will tend; hence the synonyms. Incidentally it shows that
synonyms are inseparable from any period of great botanical
activity, even when the work is in the hands of such veritable
princes in systematic work as HooKER, NUTTALL, TORREY, GRAY,
and Parry.
In 1865, Gray published E. Bloomeri (Proc. Am. Acad. 6: 540).
Taking the material then available he was more than justified.
It has taken nearly half a century of additional exploration to
lead any one to question its validity. It happened that the first
specimens of it represented it in its most depauperate stage, from
the arid mountains of Nevada. Subsequent collections greatly
extend its range, and a series of specimens leading straight into
typical E. filifolius is now at hand, and may no doubt be dupli-
cated in many of the larger herbaria. Even its raylessness is not
an infallible character. MACBRIDE secured at Silver City, on a
stony hilltop, a series of specimens that, if sorted and reported
upon by one not familiar with their history, would appear as E.
Bloomeri (rayless) and E. filifolius (radiate). These grew inter-
mingled and were intentionally collected together and placed
together upon the sheets to emphasize that fact. Under the cir-
cumstances one may even wonder why retain the name at all, but
in view of the marked differences between the extremes in the series,
perhaps the name had best stand varietally for the rayless forms.
In Coutter and NEtson’s New Manual of Botany (p. 527), the
opinion is expressed that E. curvifolius Piper, Bull. Torr. Bot. Club
27:396. 1900, is the same as E. luteus A. Nels., Bull. Torr. Bot.
Club 27:33. 1899. More careful scrutiny indicates that that opinion
416 BOTANICAL GAZETTE [NOVEMBER
was not well founded. The Chrysopsis hirtella DC. Prodr. 5:327.
1836, upon which Prper’s species was based, has a characteristic
pubescence that separates it from E. luteus and E. filifolius as well.
Since, however, there is nothing but its pubescence to separate it
from the latter, it may as well become
ERIGERON FILIFOLIUS curvifolius, n. comb.
The status of E. luteus A. Nels (loc. cit.) cannot yet be passed
upon with certainty. So far only the type collections are available,
and these show some characteristics of habit and habitat that may
denote its distinctness. If it is ever reduced it will be to separate
varietal rank under EL. filifolius.
ERIGERON coMpositus breviradiatus, n. var—Tufted on the
crown of a solitary taproot, nearly glabrous: peduncles stouter
and heads larger and broader than in the species: rays white to
pale blue, broad, shorter than the disk flowers and barely sur-
passing the involucral bracts.
E. compositus Pursh already has more described varieties than it needs
(see CouLTER and Netson, New Manual, p. 528), but the form here charac-
terized is so unique that it needs to be catalogued in some way.
Secured by Macsrive at Silver City, June 17, 1911, no. 899.
Cordylanthus (ApENosrecta) bicolor, n. sp.—Pilose through-
out, with gland-tipped, subviscid hairs: stems mostly simple at
base, rather freely branched upward, 3-5 dm. high: leaves 2-5 cm.
long, linear and entire, or pinnately 3-5-divided; lateral lobes
much shorter than the terminal, widely divaricate: heads ter-
minating the branchlets, mostly 3 or 4-flowered, subtended by 4-6
foliar trifid bracts as along as or surpassing the flowers: calyx
purple or purplish, diphyllous, the upper sepal 2-nerved, bifid,
10-12 mm. long; the lower oblong and entire, 3-nerved below,
5-nerved above, as long as or longer than the corolla: corolla
purple, tipped with bright yellow, about 15 mm. long; the two lips
equal, both appearing as if entire, but the lower with a rounded
obtuse apex, the sides infolded and with an ovate tooth longer than
the middle lobe; the sinuses plicate and having two thin lanceolate
teeth: stamens 2; the anthers 1-celled, pubescent at both base and
apex, the second cell represented by a pubescent rudiment, attached
to the filament just below the fertile one; filament flattened and
1912] NELSON—IDAHO PLANTS 417
with a U-shaped curve near the top: the stigma on the thickened
inflexed tip of the style just protruding from the orifice of the
folded galea-tip: capsule elliptic-oblong, few-ovuled, 4-6 maturing.
That this has passed for C. capitatus Nutt. seems quite probable. That
it is in reality quite distinct the following differences indicate conclusively.
No authentic specimens of C. capitatus are at hand, but it does not seem prob-
able that NutraLt, Gray, Watson, and others have all overlooked or that
they would have been silent on the following points: the glandulosity; preva-
lence of pinnatifid leaves even below; the open panicle branching (not fasci-
culate-capitate); the bracts in excess of the flowers in the head; the unequal
eaves; the inflexed lateral lobes of the lower lip of the corolla; the
laciniate plicae in its sinuses; the curved filaments and the rudimentary anther
cell; and the beautiful purple of the flowers emphasized by the yellow, pubes-
cent corolla tips.
Secured by NEtson and MacsrivE on moist sagebrush slopes, at Ketchum,
Blaine Co., July 20, 1911, no. 1239 (type); MACBRIDE, at Pinehurst, August
17, I911, no. 1671.
Pentstemon brevis, n. sp.—Densely matted in tufts few-several
dm. in diameter: roots woody, numerous, intricately interwoven:
stems very numerous, borne on the crowns of the short slender
subterranean branches of the caudex, usually 5-8 cm. high, though
sometimes higher, very minutely puberulent as are also the leaves:
leaves entire, moderately thick; the lower from oblong-elliptic to
oblanceolate or spatulate, obtuse or subacute, 5-10 mm. long,
tapering to a petiole often as long; stem leaves becoming sessile
and narrower: inflorescence a narrow glandular-pubescent thyrse:
calyx cleft into broadly lanceolate lobes 3 mm. or less long, rather
ick and green except near the base: corolla dark-blue, slender,
nearly tubular, 6-8 mm. long, bilabiate, with short rounded lobes
and with short yellow pubescence in the throat and on the sterile
filament: anthers dehiscent from the base and confluent but not
explanate.
This species reminds one, in its low densely matted habit, of P. caespitosus
Nutt., but in other respects it is more suggestive of a diminutive P. humilis
Nutt. No one seeing these three species in the field, or even in dried speci-
mens, will doubt their distinctness. P. brevis is alpine on wind swept summits.
NELSON and Macsripe, no. 1457, Lemhi Forest, Mackay, Custer County,
Idaho, July 31, torr. The only other specimen, seen by the writer, that
approaches this species is Cusick’s no. 1974, from bleak summits of Stein’s
418 BOTANICAL GAZETTE [NOVEMBER
Mountains, E. Oregon, distributed as P. humilis, but which it isnot. CusIcK’s
specimen is larger in every way and less leafy on the stems.
Artemisia potens, n. sp.—Growing in small dense patches, the
nearly simple virgate stems each from a long horizontal rootstock:
stems rather slender, pale-green, slightly striate, minutely pu-
berulent, 4-8 dm. high: leaves 3-6 cm. long, pale-green and glabrate
above, thinly tomentose below, the margins revolute, simple or
pinnatifid, the few (2-4) divaricate lobes and the body linear or
nearly so: panicle narrow, dense, 7-15 cm. long: heads numerous,
subspherical, 2-3 mm. high: involucral bracts oblong to oval, with
greenish center, nearly glabrous, the delicately scarious margins
appearing as if obscurely fringed: bracts linear, 1 or 2 to each
cluster of 3-6 heads, longer than the heads they subtend and often
nearly as long as the cluster: flowers 20 (more or fewer), the mar-
ginal ones pistillate, the inner perfect, all fertile: achenes glabrous.
In floral characters this is near A. discolor Dougl., but the aspect is that of
A. aromatica A. Nels. or A. redolens Gray. In A. potens the heads form a long
compact panicle and are as nearly erect as their crowded condition will permit.
A. discolor has a woody caudex; A. potens is herbaceous to the ground. A.
discolor grows in the moist rich soil of the mountains; A. pofens on the dry
saline-gravelly clays of the plains. The name refers to the overpowering but
wholly characteristic Artemisia odor.
Type from Mackay, July 30, 1911, no. 1413, by NELson and MACBRIDE.
UNIVERSITY OF WYOMING
LARAMIE, WYOMING
TWO SPECIES OF BOWENIA
CONTRIBUTIONS FROM THE HULL BOTANICAL LABORATORY 162
CHARLES J. CHAMBERLAIN
(WITH FOUR FIGURES)
All the cycads except Bowenia have pinnate leaves, so that
bipinnate leaves make Bowenia a very unique genus. It is found
only in Australia, and even there is limited to Queensland, ranging
from the northern part of the state to about the latitude of Rock-
hampton, in the Tropic of Capricorn.
Bowenia is described as monotypic, with B. spectabilis as the
only species, although taxonomists recognize a var. serrata, —
is often called serrulata.
B. spectabilis is found in the northern part of the range. I
found it at Babinda, near Cairns, and followed it for some distance
toward Innesfail, where it was said to be fairly abundant. Mr.
J. H. Battey, director of the Brisbane Botanical Garden, told me
that it is abundant at Cooktown; others, not professional botanists,
claimed to have seen it much farther north.
B. spectabilis var. serrata’ is so abundant in the Maryvale and
Byfield region near Rockhampton that it forms a dense, but easily
penetrated underbrush in the prevailing Eucalyptus bush. Mr. R.
Simmons, of Rockhampton, gave me directions for reaching this
Bowenia locality. I studied the variety for a distance of 20 miles
and did not see a single plant resembling the species. Similarly
in the Babinda region I had not seen a single specimen which could
have been mistaken for the variety. In fact, the differences
between the two are so pronounced that they should be regarded
as distinct species.
* Bowenia serrulata (André) Chamberlain, n. comb.—B. spectabilis Hook. f. var.
serrulata André, Ill. Hort. 26: 184. pl. 366 (1879); B. spectabilis var. serrata Bailey,
Queensland Flora 1507 (1902).—Caudex subterraneus sphaericus supra multicaulis;
eB caespitosis 1-2 m. altis; foliolis serratis.—Vicinity of Rockhampton, Queens-
419] [Botanical Gazette, vol. 54
420 BOTANICAL GAZETTE [NOVEMBER
Whether the margin of a leaflet is entire or serrate or spinulose
may be trivial in some cases and important in others, even within
the range of a single family. Dioon spinulosum was for a long time
characterized almost solely by the spinulose leaflets, but the charac-
ter is so constant that determinations based only upon this feature
are quite safe. On the other hand, the leaflets of the African
Stangeria paradoxa may show the entire or the serrate character
on the same plant or even on the same leaf. In the Botanical
Mo.
{
Fic. 1.—Bowenia spectabilis at Babinda, Australia: about 1 m. in height
Garden at Durban, South Africa, Mr. WyL1e showed me a plant of
Stangeria paradoxa with leaflets so deeply incised that the leaves
might almost be called bipinnate. In Stangeria the character is
so fluctuating that it is of no taxonomic importance. In some
species of Encephalartos the fluctuating variations in the margins
of leaflets have doubtless led taxonomists into pitfalls.
In Bowenia the serrate or entire character of the margin 1s So
constant that it would be worthy of specific rank even if it were not
1912] CHAMBERLAIN—BOWENIA 421
correlated with the difference in geographical distribution and
other features.
As found in nature, the species and the variety are noticeably
different, the latter having a greater display of foliage (figs. 1 and 2).
The species is most abundant in open places and clearings, while
the variety is most abundant in the bush. Many specimens of the
species in shaded places along streams are larger and taller than
forms growing in the open, the leaves sometimes reaching a length
Fic. 2.—Bowenia serrulata at Byfield, Australia: about 1.3 m. in height
of nearly 2 m., while those in the open seldom exceed a meter in
length, but the leaflets of plants growing in the shade never become
spinulose. The leaves of the variety range from 1 to 2 m. in height,
with about 1.3m. as the prevailing size. The leaves are dark
green, very glossy, and they retain their beauty for a long time,
especially in the species, some leaves of which, after lying for three
days on a veranda in the blazing tropical sun of Babinda, still
looked almost as fresh as when taken from the plant. The sub-
422 BOTANICAL GAZETTE [NOVEMBER
terranean stem has a remarkably tenacious hold on life. Mr.
EDWARD MEILLAND, who lives in the Bowenia region, told me that
a stem just beneath the beaten path under the house had not pro-
duced a leaf for 20 years, but when the old house was abandoned
and the path no longer used, the stem, so
long dormant, produced a fine display of
foliage.
The most striking difference between the
species and the variety isin the stem, which
is subterranean in both. In the species the
stem is somewhat carrot-shaped, with one
or two, sometimes four or five, slender
branches at the top (fig. 3). ‘These slender
branches bear all the leaves and cones.
Fic. 3.—Bowenia s pecta-
bilis: a somewhat diagram-
matic sketch of the stem of
an ovulate plant; the por- _ Fic. 4.—Bowenia eS es
tion shown is somewhat what diagrammatic sketch of ne So
less than 1 m. in length; the of a staminate plant; the mening 2s /
dotted line is the ground 23 cm. in diameter; the dotte
line. the ground line.
Sometimes they extend to the surface, but generally the bases of
the leaves and the lower third of the’cone are covered by the soil.
Root tubercles are present but are generally 10-20 cm. below the
- surface.
1912] CHAMBERLAIN—BOWENIA 423
In the variety the stem is spherical or turnip-shaped, usually
about the size of a man’s head, and has 5~20 slender branches at
the top, like those of the species, only more numerous and reaching
to the surface or even a little above (fig. 4). The slender branches
themselves often branch. As a consequence, the foliage display is
much greater in the variety than in the species. Usually, the
slender branch bears only one leaf at a time, but two or three leaves
are sometimes present. Cones are borne only on the slender
branches.
In both species and variety the slender branches arise from
buds at the top of the main stem, the buds often being due to
injuries. Where the main stem has been torn by the plow, numer-
ous buds may start.
Considering the difference in geographical distribution, the
difference in leaflets, and particularly the striking difference in the
stems, I have suggested that the variety be elevated to specific
rank. I have had the assistance of my colleague, Professor J. M.
GREENMAN, in the preparation of the description.
UNIVERSITY OF CHICAGO
BRIEFER ARTICLES
A NEW SPECIES OF ANDROPOGON
Andropogon urbanianus, n. sp.—Perennis; culmis glabris, 60-120
cm. altis; laminis teretibus, glabris; racemis binis, 2-4 cm. longis,
vagina longioribus; rachi villoso; spicula sessili glabra, a basi villosa, 5
mm. longa, arista 2 cm. longa; pedicelli sterili villoso, 5 mm. longo,
spicula pedicellata 3 mm. longa.
Perennial; culms. glabrous, 60-120 cm. high, branched above,
sheaths villous on the margin and toward the summit, or glabrate;
ligule membranaceous, ciliate, 2 mm. long; blades terete, channeled
above, glabrous, the two margins of the channel scabrous, villous above
at base, 10-20 cm. long, about 1 mm. thick, tapering to a fine point;
racemes 2 from each sheath, silky but not densely so, 2-4 cm. long,
scattered along the upper part of the culms, usually of unequal length,
the rachis joints slender, villous with long hairs, the subtending sheath
shorter than the racemes; sessile spikelets 5 mm. long, glabrous, villous
at base, scabrous above on nerves and keels, the awn geniculate, twisted
below, 2 cm. long; sterile pedicel about as long as sessile spikelet, villous
with hairs as much as 1 cm. long; pediceled spikelet reduced to a scale
3 mm. long.
Type specimen collected in Santo Domingo, Prov. Barahona near Las
Salinas, by Padre MicuEL FUERTES, no 1420, Sept. 1911. Other specimens
referred to this species are: CAMACHE (St. Michel), Haiti, “in prato montano
sicco”; W. Bucs no. 1074; Furcy, Buch 961.—A. S. Hrrcucock, Washington,
p33
EVAPORATION AND THE STRATIFICATION OF
VE TION .
(WITH ONE FIGURE)
During some investigations of the evaporating power of the air in
various plant associations, data were obtained that show the amount of
increase in the atmospheric humidity of the confined area of a ravine,
and that tend to emphasize the contention of Yapp! that the varying
* Yar, R. H., On stratification in the vegetation of a marsh, and its relations to
evaporation and temperature. Ann. Botany 23:275-320. 1909.
Botanical Gazette, vol. 54] [424
I912] BRIEFER ARTICLES 425.
evaporation conditions at different levels in the same plant association
may permit plants to grow in close proximity with one another, and
yet, vegetating principally in different strata, to be subject to rather
widely different growth conditions. _Evidence supporting this view has
also been furnished by DacHNowsk? and SHERFF from observations
extending over comparatively brief periods, all of these observers work-
ing in swamp or bog habitats.
MAY JUNE JULY AUGUST | SEPTEMBER | OCTOBER
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Fic. 1.—Diagram showing the average daily rate of — in three strata
of the beiclieeiple forest association for the growing season o
The present records were obtained during the season extending from
May 1 to October 31, rorz, in some comparatively undisturbed beech-
maple forests about 45 miles southeast of Chicago near the little village
of Otis, Ind. The forest was of the usual climax mesophytic type. Its
vegetation and the methods employed in obtaining the evaporation data
by the use of the Livincsron atmometers have been described in a
? DACHNOWSKI, A; Vegetation of Cranberry Island. Bor. Gaz. 52:126-149.
IQI1.
3 SHerrr, E. E., Vegetation of Skokie Marsh. Bor. Gaz. 53:415-435- 1912.
426 BOTANICAL GAZETTE [NOVEMBER
previous paper.4 The observations were made and the results have been
plotted graphically for three different strata, with the intervals between
the weekly readings as abscissae and the daily evaporation from the
standard LivincsTon atmometer as ordinates (fig. 1). The interme-
diate graph (fig. 1b) represents the mean of three stations situated upon
the forest floor, with the atrnometers 25 cm. above the surface of the
soil, in conditions of average vegetation. Here the average rate for the
season was 7.4 cc. per day. The highest rate (fig. 1a) is that given by
an instrument elevated 2 m. above the forest floor and shows an average
of 13.5 cc. daily, or very nearly twice the amount of the stations imme-
diately above the soil surface. The third record (fig: 1c) is for a station
situated upon the slope of a ravine 10 m. deep, cut in the clay soil by a
wet weather stream, and having a \-shaped outline in cross-section.
The atmometer was placed 4 m. below the edge of the ravine and gave
an average for the season of 5.9 cc. daily.
If the average rate of evaporation at the stations upon the forest
floor be taken as unity, the proportional evaporating power of the air in
the three strata will be found to be very nearly 1.84:1.00:0.80 for the
season, and these figures may be taken to represent, more exactly than
any previously available data, the measure of the mesophytism of these
three several regions. It may also be noted that the elevated station
has a much higher rate proportionally during the first half of the season.
The object of this paper being to indicate the amount of difference
existing in the atmospheric conditions of some of the different strata of
the same association, and to show how these differences may vary
throughout the growing season, no attempt will be made to relate the
vegetation to the different rates of evaporation. More extensive records
must be obtained and an intensive study of the composition of the
association undertaken before any satisfactory conclusions can be
reached. It is interesting and important, however, to note the different
atmospheric conditions to be encountered by forest tree seedlings during
the first two years of their existence and at a later period when they
reach the height of a meter or more. This may indicate one of the most
important reasons why so many of the beech seedlings die before attain-
ing the height of two meters. It may also be remarked that the lower
evaporation in the ravine may be a sufficient explanation for the presence
upon its slopes of a much greater abundance of such delicate forms as
Dicentra canadensis, D. Cucullaria, Impatiens biflora, and Asplenium
angustifolium.—GEORGE D. Fuiier, University of Chicago.
4 Futter, G. D., Evaporati d plant : Bor. Gaz: 52:193-208- 191T-
CURRENT LITERATURE
MINOR NOTICES
Das Pflanzenreich."—Part 46 is a monograph of the Menispermaceae by
Professor Lupwic Diets. The author devotes about 45 pages to a general
consideration of the family and then establishes 8 tribes which are based largely
on the presence or absence of albumen and the character of the endocarp.
These 8 tribes embrace 63 genera and 357 species; and approximately one-fifth
of the total number of species are new to science. Two new genera are added,
namely Platytinospora, based on Tinospora Buchholzii Engl. of tropical Africa,
and Sinomenium, based on Cocculus diversifolius Miq. of Asiatic distribution.
Part 47 continues the monographic treatment of the Euphorbiaceae by
Professor FERDINAND Pax, including only the tribe CLuytmear. The author
divides the tribe into four subtribes, namely CopIAEINAE, RICINODENDRINAE,
CLuytTINak, and GALEARIINAE, depending on the number of stamens and the
free or united petals. The tribe embraces 24 genera and about 150 species,
22 of which are new to science. One new monotypic genus (Uranthera Pax &
Hofim.) is proposed from the Malayan Peninsula. This part also includes an
elaboration of the Cephalotaceae by Professor J. M. MACFARLANE. Only one
monotypic genus of this family is known at the present time, namely Cephalotus
from West Australia.
Part 48 continues the monographic treatment of the Araceae by Professor
A. ENGLER, and contains the subfamily Lastomrae to which are referred 18
genera and upward of 130 species, 18 of which are here aise for the first
time. One new genus (Dracontioides) is described, based on Urospatha
dehiscens Schott of southern Brazil. Amorphophallus is by er the largest
genus, being represented by about 75 species or more than one-half the total
number recorded for the entire subfamily. Numerous and excellent illustra-
tions amplify the text.
Part 49 contains a supplement to the Monimiaceae by Dr. JANET PERKIN
and records the results of a continued study of this family from new shtectel
represented in the leading European herbaria, particularly the Berlin herbarium
‘ENGLER, A., Das Spear Heft 46 (IV. 94). Menispermaceae von
L. Diets. pp. 345. figs. 93 (917). 1910. M 17.40. Heft 47 (IV. 147. iii).
Euphorbiaceae-Cluytieae, pote Mitwirkung von KATHE Horrmann, von F. Pax.
Pp. 124. figs. 35 (144); (IV. 116). Cephalotaceae von J. M. MACFARLANE. pp. I5-
Jigs. 4 (24). 1911. M 7.20. Heft 48 (IV. 23C). Araceae-Lasioideae, von A.
ENGLER. pp. 130. figs. 44 (415). 1911. M6.60. Heft 49 (IV. ror. Nachisig).
Monimiaceae (Nachtriige) von J. PERKINS. pp. 67. figs. 1§ (112). 1911. M 3.60.
Leipzig: Wilhelm Englemann.
427
428 BOTANICAL GAZETTE [NOVEMBER
through the rich collections of WEBERBAUER and ULE from South America and
of Moszkowski, ROMER, and SCHLECHTER from New Guinea and New
Caledonia. Important data concerning older or little known species are
recorded, and more than 30 species new to science are added to the monograph
of this family by the same author, published in the Pflanzenreich in 1901. One
new genus is proposed, namély Carnegiea from New Caledonia. All species
enumerated are referred to in such a manner that the supplement can be used
readily and advantageously with the Monograph itself —J. M. GREENMAN.
The slime molds.—The second edition of ListEr’s Mycetozoa? is a notable
contribution to our knowledge of these much discussed organisms. The new
book follows the principal lines of the first edition, but has been improved
and ‘enlarged throughout. Six genera and 70 species have been added, so
that the group now contains 49 genera with 246 species. The plates in the
first edition were splendid, but those of the present volume are even better, and
rank with the best illustrations which have ever been published of any plant
structures. d
Miss Lister was constantly associated with her father in the preparation —
of the first volume, and the present work, published four years after his death,
shows that she is able not only to make excellent illustrations, but also to
organize and add to the text. It is distinctly a joint publication.
The “passing” of the slime molds is not referred to, the designation
“organisms” being used in all cases, so that the title Mycetozoa is the only
indication that the authors might be inclined to regard the organisms as animals
rather than as plants. Until some decisive evidence appears, there is no
reason for removing the specimens from’ the herbarium or for changing the
library catalogués.—CHARLES J. CHAMBERLAIN.
_ Handbook of deciduous trees.—In 1904 SCHNEIDER’S Handbuch began to
appear, and at the completion of the first volume (1906) it was reviewed in
this journal.3 Since that time the six parts constituting the second volume
have appeared at intervals, and have been noted. Now the work has been
completed with the appearance of the twelfth part and the general index. 4
As stated in preceding notices, it contains descriptions, with illustrations, of the
angiospermous trees of central Europe, both native and under cultivation.
The final part completes the dicotyledons (Fraxinus to Metaplexis), contains
Lister, ARTHUR, and Lister, GuLIELMA, A monograph of the Mycetozoa, 4
SOR catalogue of the species in the herbarium of the British Museum 8v
PP: 1-302. pls. 201. figs. 56. London: Printed by order of the Trustees of the British
Mascumn. IgI2
3 Bor. Gaz. 43543:214. 1907.
‘ScHNEIDER, C. K., Illustriertes Handbuch der Laubholzkunde. Zwolfte
Lieferung. Imp. 8vo. pp. Br scre vies 515-628. Jena: Gustav Fischer. 191I-
M 5. Also Register. pp. vii+138.
1912] CURRENT LITERATURE 429
the monocotyledons (Yucca to Agave),.and also an extensive supplement
(pp. 869-1065) to all the preceding parts.—J. Ce
North American flora.s—Volume 17, part 2, contains the Poaceae (in
part) from the genus Arthraxon to Paspalum by GEORGE VALENTINE NASH.
One new genus is proposed, namely Schaffnerella, based on Schaffnera gracilis
Benth. from see Several transfers are made, and new ies are described
in the following genera: Schizachyrium (4), Andropogon (1), Amphilophis
(1), Serchowrds (1), Aegopogon (2), and Paspalum (6).—J. M. GREENMAN. ~~
NOTES FOR STUDENTS
Cytology of Polytrichum.—What is to be regarded as the first critical
work on the cytology of mosses appears in a recent number of Archiv fiir
Zellforschung. ALLEN® has studied and described with great care the structure
and division of the antheridial cells of Polytrichum. For the sake of accuracy
he finds it advisable to introduce several new terms: the cells which are to be
metamorphosed into spermatozoids are referred to as androcytes, those of the
penultimate generation as androcyte mother cells, and those of all the earlier
generations as androgones.
In all androgones a deeply staining kinoplasmic mass is present in the
cytoplasm; in the earlier generations it has the form of a large ee while
in the later generations it usually exists as a group of smaller bodies or ‘“‘kine-
tosomes.” All transitions between the two conditions are found. aaies
to mitosis, the plate divides to two daughter plates, or in the case of the
kinetosomes into two daughter groups, which move apart and occupy positions
at opposite sides of the nucleus. Before the division of the plate a few achro-
matic fibers connect it with the nuclear membrane, and when the divergence
of the daughter plates is complete these have increased greatly in number,
determining the position and extent of the future broad-poled spindle. In the
cells with kinetosomes there are no fibers discernible until the migrating groups
reach their final positions. The spindle at length includes connecting fibers,
The resting nucleus contains a single deeply staining mass made up of
both nucleolar material and chromatin, and a sparse reticulum composed of
chromatin and linin. As mitosis approaches, the nucleus enlarges until its
membrane touches the polar plates or kinetosomes, while the material of the
reticulum forms a spirem which segments into chromosomes. The presence
of nucleoli at this stage offers additional evidence that the chromatin and
nucleolar substance are distinct. The nucleus now collapses and the chromatin
orth American flora, vol. 17, part 2, pp. 99-190. New York Botanical
Gane. aapery 18, 1912
C. E., Cell structure, growth, and division in the antheridium of Poly-
fae tains Willd. Archiv fiir Zellforschung 8: 121-188. pls. 6-9. 1912.
430 BOTANICAL GAZETTE [NOVEMBER
becomes compacted into a tight knot. Soon the six chromosomes, all U-shaped
and closely similar, disentangle themselves from this knot and become arranged
on the spindle. They split longitudinally, separate, and reorganize the
daughter nuclei in the usual way. During the anaphases and telophases the
away from the chromosomes, and become thickened at their ends. These
thickenings apparently move toward each other and meet in the equatorial
region, where by further swelling of the fibers the cell plate is formed. The
splitting of the-cell plate and the deposition of a wall between its halves were
not observed, but are believed to occur. :
In the androcyte mother cells there are a few granules, but nothing which
can be certainly identified with the kinetosomes, whose bulk has been dimin-
ishing through the generations of androgones. There is, however, in each of
them a small “central body” at the center of an aster in the cytoplasm. There
is no evidence that it originates within the nucleus. It divides to two which
diverge, each with an aster, to opposite sides of the nucleus. Some of the
astral rays form cones whose bases are at the nuclear membrane, but between
the separating daughter centers there is visible no constant connection. The
central bodies are located at the sharp poles of the, spindle, and as the nucleus
swells it comes in contact with them. Although they are less conspicuous
from this time on, it is reasonably certain that they persist in every instance
through mitosis, which is essentially similar to that in the androgones. In the
cytoplasm of each androcyte is a deeply staining granule occupying the position
of the pole of the former spindle. This is the blepharoplast and is doubtless
identical with the central body of the androcyte mother cell. The develop-
ment of the spermatozoid is to be taken up in a later paper.
The spermatogenous cells are marked by a condition of polarity which
persists throughout the life of each Cell and is transmitted through a long
series of cell generations. Except during mitosis, there is no trace of a polar
arrangement of the nuclear structures.
The kinetosomes are believed to be not comparable to “ chondriosomes ”
or other non-kinoplasmic inclusions of the cytoplasm. They are not definite
morphological entities, but rather unorganized masses of reserve kinoplasm.
The definite behavior of the plates in the early androgones is regarded as the
result of the presence of a large amount of kinoplasm which tends to occupy
a fairly definite position relative to the nucleus.
In contrast to the kinetosomes the blepharoplast is a definitely organized
cell organ, and although the author believes that the question of its morpho-
logical nature is still an open one, he inclines toward the view that it is the
homologue of a centrosome. This is strongly warranted by the centrosome-
like behavior of the blepharoplasts in Polytrichum, with which he ventures to
predict other bryophytes will be found to agree. The need of further researches
among the Chlorophyceae for light on the origin of the blepharoplast 1
emphasized. ;
1912] CURRENT LITERATURE 431
Although the mitosis in the antheridial cells of Polytrichum agrees in
general with that in higher plants, certain peculiarities are pointed out which
may prove to be of phylogenetic significance. Such are the delay in the
preparation of the nucleus for division until after the formation of the spindle
rudiment, the great swelling of the nucleus in one dimension during the pro-
phases, the equatorial aggregation of the chromatin following the swelling,
and the final shrinkage of the nucleus. It is yet too early to say whether any
or all of these features are generally characteristic of mitosis in bryophytes, but
many fragmentary observations make this appear quite possible.
The comprehensive review of cytological work in the bryophytes and the
extensive list of literature brought together contribute much toward rendering
this paper of the highest value to students of cytology.—LesTER W. SHarp.
Mallow rust.—In an elaborate paper ERIKSSON? gives the results
of many years’ investigations on the mallow rust, which, coming originally
from South America, has been introduced into Europe, North America, and
other countries. The work is replete with experiments and observations
covering all phases of the biology and life history of this fungus, which presents
peculiar features of interest, first, because in the countries into which it has
been introduced it has spread to many plants not native in its original habitat,
and second because, being one of the lepto-Uredinales whose teleutospores
germinate at maturity, its manner of living from season to season has not
been satisfactorily explained. It is in fact this latter phase of the subject
which forms the pivot of Errksson’s investigation, and upon which he brings
to bear the results of a vast amount of painstaking wor
The main contentions of Errksson are that the fineas persists in the
seed of infected plants in the form of a mycoplasma, and that it is disseminated
chiefly by means of infected seed. The mass of experimental and observa-
tional data upon which he bases these contentions are briefly su
ere.
The historical data relating to the distribution of the fungus show that
in many places it was first observed on plants grown from seed obtained from
infected nurseries. The fungus is not spread to great distances by means of
the sporidia. Wide dissemination is brought about by means of infected
seeds or seedling plants containing the fungus in the mycoplasma stage. In
plants grown from infected seeds the first outbreak of the disease occurs
regularly when the plants are about three months old. This period is required
for the mycoplasma to change into the filamentous stage and produce spore
pustules. The pustules of the primary outbreak are very numerous and are
uniformly scattered over the leaves of the young plant, while those of the
7 Eriksson, J., Der Malvenrost (Puccinia Malvacearum Mont.), seine Ver-
breitung, Natur, und gla an aca Kungl. Svensk. Vetensk. Handl. 47:
5-120. pls. 6. figs. 18. 1911. For s es previously published by the author
see Compt. Rend. Sessepy6-i990 IQIt, mages Centralbl. Bakt. 31293~-95- Igrt.
432 BOTANICAL GAZETTE [NOVEMBER
secondary infection from sporidia are localized in groups near the points of
infection. Neither the mycelium nor the spores survive the winter in Sweden.
The teleutospores of this rust are of two kinds, and although they are
morphologically indistinguishable, they behave differently on germination.
Those of one type produce promycelia and sporidia in the usual way, but those
of the second type produce slender germ tubes, whose terminal portions
break up into several independent cells or conidia. e sporidia put forth
germ tubes, which, penetrating the epidermis, make their way through the
epidermal cells either directly into the intercellular spaces or into the palisade
cells, and thence into the intercellular spaces. New sori result from these
infections in 8-15 days. The conidia germinate, so to speak, by pouring
their content into the epidermal cells, from which it migrates into the palisade
cells, and finally through the entire plant. No outer visible sign results from
biosis with that of the host, thus forming the mycoplasm. The seeds of such
infected plants produce seedlings in which the latent fungus manifests itself
by a general outbreak of sori over the entire plant when it is about three months
old. The change of the mycoplasm into mycelium is similar to that process
described by the author in former papers.
Two other papers published shortly before the appearance of ERIKSSON’S
account treat briefly of the mallow rust. In the first of these TAUBENHAUS®
describes the two modes of germination of teleutospores noted by ERIKSSON,
but, unlike Eriksson, he finds that the “conidia” abjointed by some of the
germ tubes produce sporidia like other promycelial cells. Furthermore, he
finds that the fungus is carried through the winter both by hibernating myce-
lium and by teleutospores. In plants in protected places, the mycelium
resulting from late infections appears to produce sori, which develop slowly
during the winter and mature the following spring. Regarding the hiberna-
tion of teleutospores, TauBENHAUS finds that the teleutospores formed late
in the season seem to behave like those of a micro-Puccinia. Some of these
he found capable of germination during the winter and spring. With the
advance of the season, however, the time required for germination increased
from 24 hours to 6 days. This observation is quite contrary to the experience
of DreteL, who found that the period required for the germination of the
teleutospores of Melampsora Larici Caprearum, a form with hibernating teleu-
tospores, decreased with the advance of the season. Young seedlings may be
infected by teleutospores borne in sori on the carpels and involucral bracts.
Thus the fungus is distributed by means of infected seed and pieces of involu-
cral bracts mixed with the seed, although the embryo is not infected.
In the second paper DANDENO? gives brief additions to his formerly
* TAUBENHAUS, J. J., A contribution to our knowledge of the morphology and
life history of Puccinia Malvacearum Mont. Phytopathology 1755-62. fais
’ DANDENO, J. B., Further observations on the life history of Puccinia Malvace-
arum. Rep. Mich. Acad. Sci. 12:91, 92. 1910.
1g12] CURRENT LITERATURE 433
published observations on the mallow rust. According to him the mycelium
of the fungus lives through the winter in the stems and petioles of Malva
rotundifolia, but the teleutospores do not survive the winter in Michigan.
though Eriksson’s observations have added many facts to those already
known of the general biology of the mallow rust, his conclusion that the fun-
gus lives through the winter only in the form of a mycoplasma in the seed or
young plant is largely inferential, and one is inclined to give preference to the
explanations of TAUBENHAUS and of DANDENO as less at variance with general
experience than is the mystical mycoplasma.—H. HASsELBRING.
ermination.—The irregularity of the differences in rapidity and per-
centage of germination in the unlike seeds of heterocarpic plants under various
conditions of germination, when the fruit and seed coats are left intact, is well
shown in a lengthy paper by BECKER,” who studied in a rather superficial way
the germination of 47 species of Compositae, several Cruciferae, and three
Chenopodiaceae. Morphological position, the sexual condition of the flowers,
darkness, temperature, increased and decreased oxygen erm nitric acid,
and Knop’s solution influence now disk seeds, now ray seeds, or both, or
neither according to species, apparently without regularity. ha and sonsihie
sterility of the seeds are disturbing factors in the results. Most of the experi-
ments were performed with fruit coats intact, but enough were removed to
prove that the inclosing structures are largely responsible for these ea
which always become much less on removal of the fruit coat. These I-
ences in germination do not, therefore, as ERNST.and CoRRENS assumed, it
on differences in the constitution of the embryos. This fact has been recog-
nized here for some years, but has not been properly recognized abroad.
Embryos of dimorphic seeds may and do differ, as the reviewer has shown* for
Xanthium; but the differences due to embryos alone cannot be determined
with seed coats left on the seeds. With Axyris amaranthoides BECKER does
not get total failure of the round seeds to germinate, as did CRocKER™ with
seeds of this plant from our northwest, but merely a very low germination.
This may be due to ecological differences in the regions where the plants grow
affecting the seed coats.
As to the influence of increased oxygen, BECKER finds that brief exposure
of seeds brings about the same kind of response as continuous exposure to
high oxygen pressures, and argues therefrom that it exerts a chemical stimulus
upon the protoplasm of the embryo, rather than increases the respiration as
CROCKER has suggested. BECKER does not tell us what is the difference
ECKER, Hans, Uber die Keimung verschiedener Friichte und Samen bei
aecsities Semchi: Inaug. Diss. pp. 7-129. 1912.
“SHULL, CuHas. A., The nee minimum and the germination of Xanthium —
seeds. Bor. Gaz. §2:453-477.
: ™ CROCKER, WM., Réle of oe coats in delayed ——- Bor. Gaz. 42: as
291. 1906,
434 ‘ BOTANICAL GAZETTE © [NOVEMBER
between increase of respiration and his postulated stimulus. I have recently
shown that there is a difference in the demand for oxygen by the embryos of
the dimorphic seeds of Xanthium, and that the embryos do not germinate
unless the minimum oxygen need is supplied. It cannot be doubted in the
case of Xanthium that the oxygen is respired, and that up to the point where
oxygen ceases to be a limiting factor, respiration increases with increased
oxygen supply. If the seed coat structures limit oxygen sufficiently, the same
conditions would obtain in any germination where free oxygen is necessary.
BECKER’s contention, therefore, seems to be without sufficient foundation,
especially since he made no attempt to measure the intensity of respiration
under the conditions of his experiments. The idea that oxygen is a stimulus
which “releases the mechanism” of germination is a conception typical of the
German school of stimulus physiologists. BECKER is therefore orthodox in
his interpretation of the less obvious chemical and physical changes in the
germination of seeds. The Germans seem to find it difficult to grasp BLACK-
MAN’s conception of limiting factors, and apply it to the problems of plant
physiology; or perhaps they merely prefer to leave the ultimate chemical
phenomena of life and growth veiled under the term stimulus, which admirably
conceals our ignorance of the real processes.
A study of the physical characters of the inclosing structures of the Com-
positae should disclose the causes of the irregular behavior BECKER reports,
and careful exact studies of the chemical processes in the germinating seeds
will show in how far the embryos are responsible for any of the noted differ-
ences.—CHARLES A. SHULL.
Cecidology.—Among the recent important European publications are
the following: A paper by RipsaAAMEN® on the cecidia of Africa and Asia
escribes and figures 38 cecidia from Africa and 6 from Asia. These are
grouped with reference to the host plants and assigned to genera only. Most
of the figures are for the purpose of showing the gross anatomical characters
of the galls,
A paper by PANTANELLI on the Acarus cecidia of the vine describes both
the hypertrophies and the parasites. It is well illustrated with phe.
of the injuries, microphotographs showing structures of the cecidia, and
drawings of the parasites. The subject is treated primarily from the aa
point of plant pathology and includes a description of one new species (P: hyl-
locontes viticolus) and an excellent bibliography.
paper by Paris and Trorrer’ gives a very important chemical study
of the well known European gall of Neuroterus baccarum and the unaffect
3 RUBSAAMEN, Ew. H., Beitrige zur Kenntnis ausser-europdischer Zoocecidien.
V. Gallen aus Africa und Asien. Marcellia 10: 100-132. 1911
™4 PANTANELLI, E., L’Acariosi della vite. Marcellia 10:133-150- 1911-
5 Paris, G., and Trotrer, A., Sui composti azotati nelle galle di Neuroterus
baccarum. Marcellia 10:150-159. 1911
ror] CURRENT LITERATURE 435
part of the foliage of the host plant. The analysis is interesting, but incom-
plete. The lengthy and well selected bibliography will be valuable for workers
in biochemistry.
A paper by Hovarp" is subdivided into five parts as follows: (1) table of
galls previously described, in which are listed 26 species with bibliography of
each and grouped with reference to the host plants; (2) new observations upon
the new galls of Tunis, in which the author gives brief discussions of 93 cecidia,
some of which are assigned to genera only; these cecidia are also grouped with
reference to the host plants; most of them are attributed to insects, one on
Moriandia cinerea Cosson is caused by Cystopus candidus, one on Olea europaea
L. is caused by Bacillus olea (Arc.) Trev., and a third is referred to as a fas-
ciation without comment as to cause; (3) a very valuable bibliography on
the zoocecidia of Tunis from 1894 to date; (4) a table of galls arranged with
reference to host plants; (5) a table arranged with reference to the organisms
causing the galls.
CosTERus and Smit” have represented a very interesting paper on tropi-
cal teratology. Malformations of 18 species (7 of which belong to the family
Orchidaceae) are carefully described. These descriptions are far better than
those frequently given in papers on teratology in that the relationships of the
parts have been carefully worked out. No a ceageeds is offered as to the
cause of these peculiar structures.—MEL T. Cook.
Gas movements in plants.—It is a question of some interest whether
static diffusion accounts for essentially all the gas exchanges of foliar inter-
cellular systems or whether molar movement is also considerably involved.
Onno” has already shown how “hygro-diffusion” leads to such a molar extru-
sion of gas in the leaf of Nelumbo nucifera, and has explained the physics of
the action. Now Ursprunc” shows that the same process plays an important
part in the gas movements in the leaves of Nymphaea and Nuphar. The first
half of the article is devoted to a critical historical review of the work on
Nelumbo. The conclusions reached agree with OxNo in all essential points,
although that author has given the earlier literature a less critical considera-
tion than is desirable. As Ursprune states, it has generally been believed
that the observed gas exchanges and positive and negative pressures in the
intercellular systems of Nymphaea and Nuphar are entirely determined by
photosynthetic and respiratory activities. A mention of two of his experiments
will show clearly that “hygro-diffusion”’ plays an important réle in these forms.
© Hovarp, C., Les Zoocédicies de la Tunisie. Marcellia 10: 160-184. 1912.
7 CostERus, J. C., and Sarru, J. H., Studies in tropical teratology. Ann. Jard.
Bot. Buitenzorg IT. 9:98-116. pls. 5. 1911.
*® Bor. Gaz. §1:310. 1911.
*? Ursprune, A., Zur Kenntnis der Gasdiffusion in Pflanzen. Flora 104:129-
156. 1912.
436 BOTANICAL GAZETTE [NOVEMBER
If the cut end of a petiole of a leaf of Nymphaea is placed just beneath the water
surface while the upper face of the leaf blade is in the air, gas of about the com-
position of the air continuously extrudes from the cut end of the petiole with
pressures varying from o to 17cm. of water, and in volumes amounting to
several times that of the leaf in course of an hour. Both the pressure and
rate of extrusion increase with a rise of the temperature of the leaf and with
dryness of the air in contact with the upper surface of the blade, and ceases when
the air over the blade is saturated or when the blade is immersed. By piercing
the upper surface of the blade of Nymphaea just over the petiole repeatedly
with a needle, turning up the margin of the blade, and supporting a little water
over the punctures, a great extrusion of air can be demonstrated, increasing
with the temperature of the leaf and with dryness of the air over the marginal
region of the blade. This is almost identical with the main observations on
Nelumbo, and is explained by the same physical principle. Ursprune believes
that a considerable part of the gas exchange in leaves of water plants floating
or borne above the water is brought about by “hygro-diffusion,” but that it
lays no considerable réle in the gas exchange of land plants with their narrow
intercellular systems, and of course no part in submerged leaves. The studies
and UrspRuNG now make possible a much more lucid statement of
gas movements and pressures in the intercellular systems of plants than was
formerly” the case.—WILLIAM CROCKER.
Cytology of rusts.—Investigations of the cytology of Puccinia
Falcariae by Dirrscutac# and of Endophyllum Sempervivi by HOFFMANN”
show that the sequence of nuclear phenomena in these forms agrees in its
essential details with that of other rusts. Among the facts presented the
following are of special interest. In Puccinia Falcariae, which is an autoecious
form of the Puccinopsis type, the binucleate phase arises by the lateral fusion
of the cells of a palisade-like layer differentiated near the lower middle of the
young aecidium. Unlike the mode of origin of binucleate basal cells in
the true aecidia of Puccinia Poae as described by BLACKMAN and Fraser, the
mode of origin of these cells in Puccinia Falcariae resembles more nearly
that usually observed in aecidia of the Cacoma type, in which the fertile cells
are not overlaid with a mass of sterile tissue. Occasionally three cells fuse
and thus trinucleate basal cells arise. Occasionally the basal cells branch
and form more than one row of spores. Regarding the trichogyne-like cells
observed by some investigators, the author states that the so-called sterile
cells are not always present, but when they are they occur on both sexual cells.
70 PFEFFER, W., Plant physiology. Eng. ed. Vol. 1. pp. 199. 1899.
* DirtscaLaG, E., Zur Kenntnis der Kernverhiltnisse von Puccinia Falcariae.
Centralbl. Bakt. IT. 28: 473-492. pls. 3. figs. 6. 1910. . :
” HorrmMann, H., Zur Entwicklungsgeschichte von Endophyllum Sempervivt.
Centralbl. Bakt. 32:137-158. pls. 2. figs. 14. 1911.
1912] CURRENT LITERATURE 437
The life history of Endophyllum Sempervivi is peculiarly interesting
because in that form the aecidiospores function as teleutospores. HorrmaNN
finds that the binucleate basal cells arise from fusion of cells in the lower part
of the aecidium. The axis of fusion, however, may lie in any direction, and
there is no palisade-like arrangement of the fusion cells. The paired nuclei
of the gion fuse and the subsequent processes are like those in teleu-
tospores. The sporophyte phase is restricted to the saa a mother cell
and the two cells lectidieepont and intermediate cell) formed fr
In both of these forms the binucleate cells arise from the fasion of fertile
cells, whose contiguous walls are dissolved. In this respect the process differs
from the migration of nuclei through pores as described by BLACKMAN in
account of Phragmidium violaceum
In a short note BEAUVERIE”3 ‘cae further observations on the “cor-
puscules métachromatiques” which he finds in the mycelium of an unidenti-
fied rust of wheat and also in the host cells. The author now identifies these
bodies with the “excretion bodies” of Zacu, and believes they remain in the
host cells after the hyphae themselves have been digested.—H. HASSELBRING.
Embryo sac of Gunnera.—Ever since the investigation of Gunnera (Halo-
ragidaceae) by SCHNEGG in 1902, the genus has been included with those inter-
esting angiosperms (as Peperomia) displaying an excessive number of nuclei
in the embryo sac preceding fertilization. It was very desirable to study the
situation more critically, and this has been done by Samuets* for G. macro-
bhylla. The sequence of events is as follows: The solitary hypodermal
archesporial cell (mother cell) develops directly into the embryo sac, no tetrad
in the ordinary sense being formed. At the first (heterotypic) division of its
nucleus the reduced number of pigedensiney ie ve was repeatedly observed to be 12.
At the second division (four nuclei) t lar polar posi-
tion, and the other two are against the wall of the sac in the equatorial plane,
and a little later move toward the antipodal pole. The polarity of the sac is
thus attained at the 4-nucleate state. At this time the inner integument fuses
to close the micropyle, and therefore the pollen tube was observed to pierce
the integuments to reach the sac. The numerous vacuoles that appear during
the second division fuse into a large central vacuole during the development
of polarity. At the third division (eight nuclei) the upper one of the two micro-
pylar nuclei divides to two nuclei side by side; and at the fourth division
(16 nuclei) each of these two nuclei divides to two nuclei vertically placed.
These four micropylar nuclei are the egg, the synergids, and the micropylar
3 BEAUVERIE, J., La signification des corpuscules métachromatiques dans les
cellules de céréales infestées par la rouille. Compt. Rend. Soc. Biol. 70: 461-463. 1911.
24 SamueELs, J. A., Etudes sur le développement du sac embryonnaire et sur la
fécondation cm Connin macrophylla Bl, Archiv fiir Zellforsch. 8:53-120. pls. 3-5.
Sigs. 23. Igr2.
438 BOTANICAL GAZETTE [NOVEMBER
polar, not merely in position but also in function. The micropylar polar
then fuses with the upper six nuclei toward the antipodal region, resulting in a
fusion nucleus of seven nuclei; while the remaining six nuclei form the antipo-
dal complex. The cells of this sete enlarge after the entrance of the tube,
but oe Lage they degenera
atogenesis was also Ce verifying the chromosome count, and
a reten a enable behavior of the pollen grain in frequently sending two
tubes into the same style. Double fertilization was observed, so that the
ee enti nucleus finally becomes a fusion of eight cells.
AMUELS discusses at length the relation of such a 16-nucleate embryo sac
to the embryo sacs of gymnosperms. He also concludes that such a sac
represents four megaspores in its origin.—J. M. C.
Paleobotanical notes.—In 1906 Scott published briefly the genus Boiry-
chioxylon, and now there has appeared the full account.** The genus is of
special interest in being a true fern (Botryopterideae) in which a stele of simple
form “has advanced in the direction of substituting secondary for primary
xylem.” There is also anatomical evidence that it holds an intermediate
position between Botryopterideae and Ophioglossaceae, thus linking the latter
with the ancient ferns.
ARBER®” has described a new species of the problematical genus Psygmo-
phyllum, from the Lower Carboniferous of Newfoundland, and in a revision of
the genus recognizes six species, distributed from Upper Devonian to Permian.
As to the affinities of the genus, nothing can be determined in the absence of
fructifications. There is a suggestive resemblance of the leaves to those of
Ginkgo, but ARBER is convinced that the similarity is purely artificial. He
associates the genus with other genera of the Paleozoic (as Ginkgophyllum,
eae ae tae etc.) as a distinct group under the name Palaeophyllales,
may or may not have been the ancestors of the Ginkgoales.
Dr. Stopes” has recorded the existence of angiosperms in the Aptian
(Lower Cretaceous) of England, an earlier horizon than any in which angio-
sperms were known to occur. The specimens are in the collections of the
British Museum of Natural History, and have been made the basis of the
description of three new genera (A ptiana, Woburnia, Sabulia). The structure
of the wood lends no support to the view that angiosperms arose from gymno-
sperms, since it is like that of high-grade angiosperms in all details. The wood
** Scott, D. H., On Botrychioxylon paradoxum, sp. nov., a paleozoic fern with
secondary wood. Trans. Linn. Soc. London II. Bot. 73373-3809. pls. 37-41. 1912-
6 ARBER, E, A. NEweLL, On Psygmophyllum dor cto . nov., from the Lower
Carboniferous rocks of evlounieaa, together with a revision of the genus and
remarks on its affinities. Trans. Linn. Soc. tine II. Bot. 73391-407. pls. 42-44
jig. I. 1912.
77 Stopes, Marre C., Petrifactions of the earliest European angiosperms. Phil.
Trans. Roy. Soc. London B 203:75~-100. pls. 6-8. 1912.
1912] CURRENT LITERATURE 439
does not occur in definite bundles, and the rays of Aptiana are multiseriate.
The question of genetic connections must await further information, but the
author well remarks that the chief importance of these three genera “is that
they are so old, and that they prove the existence of undoubted higher woody
angiosperms in Northern Europe at this time.”—J. M. C.
The biology of Uredinales. An excellent summary of our knowledge
of Uredinales is given by Marre.* Since the article is itself of the nature of a
review, it needs to be mentioned here merely with reference to its scope, and
to indicate new matter'and views introduced by the author. The subject
is treated under two heads: (1) the individual evolution and the sexuality of
the oo and (2) the relation of the Uredinales to their hosts and to their
environm
The one ‘park is chiefly an account of recent progress in the cytology of
the rusts, with a brief exposition of the theories regarding their origin. The
author himself believes the Uredinales and the higher Basidiomycetes to have
had a common origin with the Ascomycetes. This view is based mainly on the
presence of apparently functionless spermatia in the rusts and in some of the
Ascomycetes, and on the existence of minute conidia possibly representing
ancestral male cells among the Basidiomycetes
In connection with the discussion of hose rusts which have shortened
life histories, the author introduces an amplification of SCHROETER’s classi-
fication of these forms. By taking into consideration all the spore forms,
including the spermatia, he obtains the following biological groups: O-I-II-
III, eu-Uredinales; I-II-II, cata-Uredinales; O-II-III, brachy-Uredinales;
O-IIT, hypo-Uredinales; O-I-III, opsi-Uredinales; I-III, catopsi-Uredinales;
II-III, hemi-Uredinales; II, pyro-Uredinales. Heteroecism and autoecism
are expressed by the prefixes Aetero- and auto- in the manner suggested by
Duccar.
The second part takes up such more general phases of the work on biology
of rusts as the types of development of the Uredinales, the réle of the different
_ Spore forms, dissemination and infection, and the more theoretical questions
relating to the host- relationships and the origin of species and of heteroecism
within the group, and finally the various types of morphogenic changes induced
by rusts in their hosts.—H. HasSELBRING.
The mistletoes.—At the April meeting of the National Academy of
Sciences, Dr. TRELEASE presented a revision of Phoradendron. An abstract
of his paper is as follows: There are distinguished 83 forms of this exclusively
American genus of mistletoes on the mainland north of the Isthmus, of which
72 are regarded as species and the remaining 11 as varieties. About half of
them are Mexican, one-fourth Central American, and one-fourth belong to the
8 Marre, René, La biologie des Urédinales. Progressus Rei Bot. 4:110~-162.
IgIr,
440. BOTANICAL GAZETTE [NOVEMBER
United States. Three main groups are recognized: one with very few-flowered
spikes, growing on conifers, about equally divided between the United States
and the Mexican highlands, comprising 12 species; one with more numerous
flowers, growing on various angiosperms, comprising 11 United States and 18
Mexican species, also limited to the North; and one, differing from the second
in the constant presence of scales at the base of at least its lowermost a
nodes, containing 14 Mexican and 17 Central American species. The
two groups are distinctly boreal and neither passes into the West Indies. a
third group is distinctly equatorial, disappears well below the boundary between
Mexico and the United States, and contains the exclusive representation of the
genus in South America and the Antilles, more than half of its species occurring
in this extralimital region. Except for two of these tropical species to which
a wide range is ascribed, none occurs over so large an area as the common
mistletoe of the eastern United States, which in distribution about coincides
with the bald cypress.
A new aquatic fungus.—Allomyces arbuscula, a new generic type
of the Leptomitaceae, has been described by BuTLER,® who found the fungus
growing on dead flies in still water in Pusa and Poona, India. The individual
plants consist of a basal cell which is attached to the fly by means of rhizoids,
and at the:apex branches more or less dichotomously to form a fan-shaped
body of a few short cells. These give off slender branches which terminate.
either in zoosporangia or in sporangia containing a single thick-walled, brown
resting spore. After the formation of a terminal sporangium, the axis: is
oar ei by a branch arising below the sporangium. Thus a sympodi
sys is built up as in Phytophthora. The fungus is peculiar in having 2
soxapletely septate thallus, not usual among the Phycomycetes. The author —
regards it as a near ally to Blastocladia on account of the peculiar partheno-
genetically developed oospores, which he suggests may have been derived from.
the Monoblepharis type through loss of the motile sperms.—H. HASsELBRING.
amare ie - On Allomyces, a new aquatic fungus. Ann. Botany 25: 1023-
1035. figs. 8.
3° BETTS ten D., A bee-hive fungus, Pericystis alvei, gen. et sp. nov. Ann.
Botany 26:795-799. pls. 75, 76. 1912.
Vol. LIV
THE
December rox2
Editor: JOHN M. COULTER
CONTENTS
The Life History of Cutleria | , Shigéo Yamanouchi |
The Nature of the Absorption and Tolerance of Plants in
Bogs Alfred Dachnowski
Ingrowing Sprouts of Solanum tuberosum G. Stuart Gager
The Abortive Spike of Botrychium O. O. Stoland
Plants Which Require Sodium W. J. V. Osterhout
Briefer Articles
The Perfect er of the Ascochyta on the Hairy Vetch
George F. Atkinson
Gautieria in the Eastern United States George F. Atkinson
Current Literature
The University ‘of hee siscti Press
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Agents
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sige: STAUFFER, Leipzig
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BOTANICAL GAZETTE
Che Botanical Gazette
H Montbly Journal Embracing all Departments of Botanical Science
Edited by Jonn M.° Coulter, with the assistance of a members of the botanical staff of the
University of Chic
Issued December 16, 1912
Vol. LIV CONTENTS FOR DECEMBER 1932 No. 6
THE LIFE HISTORY OF east ConTRIBUTIONS FROM THE HuLL BorantcaL Lapora- ;
TORY 163 (WITH FIFTEEN FIGURES AND PLATES XXVI-xxxv).. Shigéo Yamanouchi ~- 441
THE NATURE OF. THE ABSORPTION AND TOLERANCE OF PLANTS IN BOGS.
Alfred Dachnowsk - . “ 503
INGROWING SPROUTS OF SOLANUM TUBEROSUM Suse PLATE XXXVI AND SIX x TG)
C. Stuart Gager - — - . 515
THE ABORTIVE SPIKE OF BOTRYCHIUM. Conrrisutions FroM THE Hutt BoTaNicaL
LABORATORY 164 (WITH TWENTY-ONE FIGURES). O.O. Stoland - - * 525
_ PLANTS WHICH REQUIRE SODIUM (wire two Ficures). W.J.V. Ostephout = 2 2s => 1557
BRIEFER ARTICLES
Tue Perrect STAGE oF THE ecoerk ON THE Hairy VETCH. George FP. Atkinson - S53
Gavrmerra IN THE Eastern Unirep States. George F. Atkinson - - of See
CURREN T LITERATURE
Tem MOTOR Go ibe ER te oy es OR ie rath ok Le a
“NOTES FOR STUDENTS. Be FO fete tage) tr ee ee
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VOLUME LIV NUMBER 6
LE
IOTANICAL “G4NZETIE
DECEMBER 1912
THE LIFE HISTORY OF CUTLERIA
CONTRIBUTIONS FROM THE HULL BOTANICAL LABORATORY 163
SHIGEO YAMANOUCHI
(WITH FIFTEEN FIGURES AND PLATES XXVI TO XXXV)
Introduction
This paper deals with nuclear conditions in Culleria multifida
J. Ag. and Aglaozonia reptans Crouan, both of which are found in
the Bay of Naples. In common with Zanardinia, another member
of the Cutleriaceae, Cutleria and Aglaozonia are characterized by
having large motile spores. The vegetative body and method of
forming reproductive organs show a combination of characters
found in Ectocarpus, Sporochnus, Tilopteris, Sphacelaria, Battersia,
Zonaria, Padina, and Laminaria, genera belonging to different
families.
The large motile spores attracted the attention of THuRET (63),
who was the first to do experimental work with Culleria multifida.
THURET was followed by many investigators who made cultures
of the spores in order to determine whether Cutleria and Aglaozonia
might be.two alternating generations of one life cycle, but the
results were conflicting.
FALKENBERG (12), working with material from Naples, first
suggested that Aglaozonia parvula is the asexual form of Cuileria
multifida, and that Aglaozonia chilosa is the asexual form of
Cutleria adspersa. Cuurcu (6), with material from Plymouth, con-
nected Aglaozonia reptans with Cuileria multifida, and SAUVAGEAU
(43-51), with material from Guéthary and Banyuls, proved that
441
442 BOTANICAL GAZETTE [DECEMBER
Aglaozonia melanoidea is the asexual form of Cutleria adspersa. The
conclusions of these authors were drawn chiefly from a comparison
of young forms of Cutleria collected in nature with young plants
obtained from cultures, the emphasis being laid upon outer morpho-
logical characters.
It is not necessary to present a detailed historical review of
previous work, for many authors, especially SauvAGEAU (45),
have given such reviews. Since 1899 no work based upon original
investigation has been published except by SauvaGEAU and the
present author. Papers by SAuvAGEAU (46-51) confirm his work
of 1899, and a paper by the author (76) is the preliminary account
of the present paper. Before turning to our own investigation, we
shall indicate briefly what has been accomplished already, and what
still remains to be done.
The first definite account of the discharge and the culture of
spores of Cutleria was made by THuretT (63), who observed that
the female gametes germinated parthenogenetically. The male
plants of Cutleria he found to be extremely rare at Saint Vaast-la-
Hogue, France, where his cultures were made. This partheno-
genetic product, a small plant somewhat resembling Ectocarpus,
did not live long. According to SAUVAGEAU’s suggestions (45)
the plant may be designated as form Thuretiana. Five years later
the brothers Crouan (7), by repeating these observations at Brest,
France, came to the same conclusions. DrErsés and SoLreR (11),
working on the Mediterranean coast of France, confirmed THURET’S
account. Thus these earlier observers, who worked on the French
coast, seem to have entertained no doubt of the constancy of the
parthenogenetic germination of the female gametes of Cuileria.
About two decades later two German botanists, REINKE and
FALKENBERG, independently making cultures at the Naples
Station, reported quite different results. REINKE (38, 39), work-
ing at the Station in 1875-1876, observed the actual fertilization of
the female gametes by the male gametes of both Zanardinia and
Cuileria. In vessels containing both male and female gametes
germination took place freely. There seemed to be no germination
of the unfertilized egg. RrmNKE concluded that sexual reproduc-
tion prevailed in Cudleria multifida and that THURET must have seen
1912] YAMANOUCHI—CUTLERIA 443
only exceptional cases of parthenogenesis. He states that in the
Bay of Naples the male and female plants occur in the ratio of 3
to 2. He obtained filaments of both Zanardinia and Aglaozonia
which produced non-motile spores. In the cultures of Cuileria,
Desmotrichum finally appeared, and consequently the ultimate
products of the fertilized female gametes were not clearly followed.
FALKENBERG (12) in 1878, taking great care to obtain pure
cultures of both fertilized and unfertilized female gametes, fully
demonstrated the necessity of fertilization for germination. The
female gametes, entirely separated from the male gametes, retained
their capacity for fertilization for four or five days and then never
grew beyond the formation of a thin cell membrane. FALKENBERG
not only demonstrated the necessity for fertilization, but succeeded
in developing the sporelings to a considerable size; in 6-8 weeks
the sporeling in the stage of ‘foot embryo” (Keimfuss) had
developed as a secondary lateral outgrowth the creeping flat form
(kriechende Flachsprosse), which is identical with the creeping
thallus of Aglaozonia. This kind of sporeling may be designated
as form Falkenbergiana. FALKENBERG was the first to associate
Cuileria multifida with Aglaozonia reptans, and Cuileria adspersa
with Aglaozonia chilosa. Four years later JANCZEWSKI (21), at
Antibes, did with Cutleria ads persa what REINKE and FALKENBERG
had done with Cutleria at Naples, and showed that unfertilized
gametes of Cutleria adspersa do not develop further.
In 1894 Kuckuck (24) described a plant under the name of C.
multifida var. confervoides. The plants came up in the tank of the
Helgoland Laboratory in the summer of 1893, and were attached
to stones which had been collected in the North Haven in fairly
shallow water of 1-3 fathoms. The plants were monosiphonic and
some of them were in the reproduction stage. The normal Cuileria
is said to have been gathered at Helgoland by WoLtny, but has
not been known to occur there since. The origin of the plant is
not clear.
The cultures of Cuéleria and Aglaozonia made by CHURCH in
1898 were from material collected in English waters. CHurcu (6)
Obained the material by dredging in the estuary of the river
Yealm, near Plymouth, England, at 2-3 fathoms below low water
444 BOTANICAL GAZETTE [DECEMBER
mark. The male plants of Cuileria multifida were very rare, and in
cultures of the female gametes there was produced parthenog -
cally a form identical with the form Falkenbergiana. Further,
from the zoospores of Aglaozonia parvula CHURCH obtained plants
which, like the preceding, have the creeping platelike thallus of
Aglaozonia, but whose column ends at the summit in filaments (not
fascicled) which bear the male gametangia of Cutleria. The latter,
being entirely a new form and having never been obtained by any
previous investigators, may be designated as form Churchiana.
Finding that the female gametes develop parthenogenetically andthe
zoospores of Aglaozonia produce Aglaozonia directly with no alter-
nating appearance of Cuéleria, CHuRcH concludes that Culleria
-and Aglaozonia represent simply polymorphism due to environ-
mental conditions, especially such as changes in the temperature
of water.
In 1898 SAUVAGEAU (43) reported that he found in nature,
epiphytic upon adult Cuileria adspersa, a number of young spore-
gs of the same species. These sporelings were of two kinds, forms
Thuretiana and Falkenbergiana, which were evidently growing
side by side, at the same time, and on the same spot under similar
conditions. In the summer of 1898, Kuckuck (25) obtained in
cultures at the Helgoland Laboratory a number of young plants
germinating from the zoospores of Aglaozonia parvula. The young
plants had the characters of the form Thuretiana, and in his material
female gametangia of Cudleria were produced. Besides, some of the
plants produced a creeping disk, so that the whole structure
resembled the form Churchiana, but the form Falkenbergiana never
appeared.
SAUVAGEAU (44, 45) found at several points on the coast of the
Gulf of Gascony, France, a new Aglaozonia, the Zonaria melanoidea
Schousboe, discovered at the beginning of the century at Maroc
and not reported since, whose Aglaozonia nature remained unrecog-
nized. SAUVAGEAU considers Aglaozonia melanoidea to be the
sporophyte of Cutleria adspersa. In cultures of Cudleria adspersa
which he collected at Guéthary (Basses-Pyrénées), he observed
that the female gametes did not attract the male gametes. The
female kamoates germinated very readily parthenogenetically and
1912] YAMANOUCHI—CUTLERIA 445
gave always and characteristically the form Falkenbergiana. In
1905 SAUVAGEAU (47, 48) collected Aglaozonia melanoidea at
Banyuls-sur-Mer (Pyrénées-Orientales), and in winter and early
spring in each successive year of 1905-1908, he (46-51) carried
on his cultures at the Laboratory Arago, Banyuls. From the
zoospores of Aglaozonia melanoidea he obtained, in a majority
of cases, Cuileria adspersa, and in only one case out of too did he
obtain Aglaozonia melanoidea; but neither the form Churchiana
nor the form Kuckuckiana was produced. Unfertilized female
gametes of Cutleria adspersa produced either Aglaozonia or Cutleria.
From his own results and those of previous investigations,
SAUVAGEAU concluded that the alternation of two generations is
not necessary, but rather, as it might be said, facultative. Otr-
MANNS (35), from results of previous authors, considers Cudleria as
presenting no true alternation with the Aglaozonia generation, but
as simply presenting another instance of polymorphism in algae.
STRASBURGER (59), discussing the alternation of generations in
Phaeophyceae, agrees with the views of SAUVAGEAU and OLTMANNS.
| these investigations, discussions, and conclusions were made
without any reference to nuclear conditions. The cytology of
Cuileria and Aglaozonia was first described by the author as a
preliminary note three years ago (74).
The material for the present investigation was collected at the
Bay of Naples in the winter of 1908 and spring of 1909, during which
time I occupied a table of the Carnegie Institution at the Stazione
Zoologica. Cutleria multifida was found growing on rocks at a depth
of 1-5 meters in the vicinity of Posilipo and Castello dell Uovo,
and Aglaozonia reptans was growing on the surface of echinoderm
shells or stones in the same localities and also at Nisida along the
Bay of Naples, often at a greater depth. A fresh and plentiful
supply of material was furnished by Dr. SatvAtore Lo Branco
almost every day. Cultures of the plants and of their sporelings
and the fixation of their critical stages were made in the labora-
tory of the Station, where by the kindness of Drs. ANTON DoHRN
and REINHART Dourn the author enjoyed every equipment for
facilitating the work. The investigation thus begun at Naples
was finished at the Hull Botanical Laboratory of the University of
446 BOTANICAL GAZETTE [DECEMBER
Chicago. To Professor Joun M. Coutter and Professor CHARLES
J. CHAMBERLAIN I wish to express my thanks for their suggestions
and criticisms throughout the investigation.
The paper presents the results of my studies on Cutleria and
Aglaozonia. For Cutleria there is described the mitosis in the
vegetative cells of the male and female plants, the formation of the
male and female gametes, the fertilization and the germination of
the fertilized female gametes, and the germination of the unfertilized
female gametes; for Aglaozonia the mitosis in the vegetative cells,
and the formation and germination of the zoospores. Finally, there
is a brief discussion of the cytological phenomena and the alter-
nation of generations.
Cutleria multifida
Cutleria multifida J. Ag. is generally dioecious, and the forms of
the male and female plants vary with the localities in which they
grow. At one place, the male plants are more broadly multifid and
shorter than the female, which are very narrowly multifid and often
reach a length of 25 cm. or more; in other localities the reverse is
true, that is, the male plants are narrowly divided and larger than
the female plants. An extensive comparative study of the forms
shows that there is great variability in habit, so that it seems
impossible to distinguish the two mature sexual individuals by any
gross morphological aspects, except that they bear, as a rule,
exclusively either male or female reproductive organs. Cutleria
grows in the Bay of Naples upon rocks or mollusk shells, at a
depth of 1-5 meters. The Cuéleria material was collected with the
rocks or shells upon which it was growing, and there was always an
abundant display of the successive stages in the development of the
plants, from the very young thallus to large adult forms. The
young thallus is 1-3 mm. in length, narrowly funnel-shaped, and
presents no feature to distinguish the male plants from the female.
MITOSIS IN THE VEGETATIVE CELLS OF THE MALE AND
FEMALE PLANTS
Both male and female plants, when fresh, always bear a beauti-
ful fascicle of hairs at the tips of the multifid filaments of the thallus,
and scattered here and there upon the whole surface of the thallus
1912] YAMANOUCHI—CUTLERIA 447
there are also tufts of hairs. Any part of the frond in vigorous
growth is favorable for the study of vegetative mitosis, but details
are more easily and definitely followed in the hairs and in the super-
ficial layer of the thallus. — :
The cells in these regions are full of plastids, with usually a single
nucleus in the center. The nucleus in the resting stage is very
Fic. 1.—Cuitleria multifida: portion of a thallus with a number of filaments and
young male gametangia.
small, generally about the size of the plastids or slightly larger
(figs. 1, 5, 16, 53). The network is so fine that it is hard to recognize
much chromatin init. Neither centrosome nor central bodies with
or without radiations seem to be present.
In early prophase the nucleus increases in size, until it becomes
three or four times the diameter of the resting nucleus and is a
conspicuous structure within the cell. During the growth of the
448 BOTANICAL GAZETTE [DECEMBER
nucleus, just inside the membrane, there appear chromatin knots
which are evidently worked out of the chromatin network by the
rearrangement of the material. These chromatin knots, which
are continuous with less deeply stained chromatin fibrils, are vari-
able in number at first, but gradually the number of chromatin
knots becomes definite and they are detached entirely from
the chromatin fibrils and become the chromosomes, 24 in number
(figs. 19, 54). The chromosomes, after segmentation, gradually
assume a slightly elongated rod form and become arranged at the
equatorial plate (figs. 20, 55).
A little before the equatorial plate stage, from the cytoplasm
surrounding the nuclear membrane, kinoplasmic accumulations
arise at the poles. A well marked centrosome-like structure in the
kinoplasmic masses occurs only at the metaphase. The chromo-
somes split longitudinally and half of each chromosome proceeds
to each pole (figs. 22, 56). During this entire process the spindle
is intranuclear. At telophase the nuclear membrane disappears and
the two sets of daughter chromosomes, crowded closely together,
are surrounded by cytoplasm, and the formation of the nuclear
membrane follows (figs. 28, 57).
When the daughter nuclei are organized, the central spindle
disappears completely (figs. 29, 57). The cytoplasm lying between
the two nuclei begins gradually to assume a coarse, irregular,
alveolar structure, and the walls of the alveoli, probably after a
change in their material, form a new cell plate. Vegetative mitosis
is essentially the same in both male and female plants.
The size of the nucleus varies according to the portion of the
thallus in which the nucleus is contained. The hairs and super-
ficial cells contain larger nuclei than the huge cells situated below
the superficial cells; however, even those in the hairs and superficial
cells vary in size. There seems to be no relation between the size
of the nucleus and that of the cell. Quite frequently the narrow
cells in the hairs contain larger nuclei than the elongated cells;
usually the marginal cells in the superficial layer of the thallus have
larger nuclei than the others. On the whole, the nuclei of the female
plants are slightly larger than those of the male plants. However,
such a difference, if it exists, is not very great during the vegetative
Igt2]
YAMANOUCHI—CUTLERIA
— 449
division, but the conspicuous difference in size appears in the forma-
tion of the reproductive organs.
THE MALE GAMETANGIUM
Mature male gametangia.—Male gametangia occur all over the
surface of the thallus in small or in large clusters (figs. 1, 2, 3, 4).
When the male plant is young,
before the appearance of game-
tangia, the surface of the thallus
bears tufts of hairs here and
there in somewhat regularly
scattered spots. Later, with or
without the association of the
hairs, young male gametangia
appear. Both the male game-
tangia and hairs arise from
superficial cells of the thallus.
The mature male gametan-
gium consists of a number of
tiers of small cells (the male
gamete mother cells), each tier
composed of~8 cells, and since
there are more than 22 tiers
(fig. 4), the output of male
gametes from a single game-
tangium is about 200. The ma-
ture male gamete in the free
swimming condition outside of
the gametangium has an ova
shape (fig. 8, 2) and usually con-
Fic. 2.—Cutleria multifida: a filament
bearing a few male gametangia in succes-
sive stages of development.
tains two plastids. Associated with one of the plastids, inside of
the lateral face of the plasma membrane near the anterior end, is
a red pigment, and in close association with this pigment are two
cilia of different lengths, the long cilium directed toward the
anterior end, 4.5 times the long diameter of the gamete, and the
short one in the opposite direction, about twice the diameter of
the gamete.
(figs. 3 and 4).
The long diameter of the entire male gamete is 5 #
450 © BOTANICAL GAZETTE [DECEMBER
Development of male gametangia.—As was stated above, both
the hairs and gametangia arise from the superficial cells of the
thallus.
One of the superficial cells commences to grow more vigorously
than the rest (fig. 17) and a typical nuclear division takes place,
which gives rise to a gametangium initial and a stalk cell. Some-
3 oe
Fics. 3, 4.—Culleria multifida: fig. 3, one of the male gametangia, with a long
stalk composed of several cells; fig. 4, gametangia near maturity; one of them has
22 tiers of mother cells.
times 2-7 or more subsequent divisions occur and there is produced
a filament of two or more cells, the terminal one of which is destined
to be a male gametangium initial (figs. 1, 3, 4). Or a filament
becomes a long multicellular structure of a single row of cells, and
from a number of these cells there are produced lateral branches,
consisting of one, two, three, or more cells, the terminal one of
which becomes the gametangium initial (figs. 2, 21, 39).
1912] YAMANOUCHI—CUTLERIA 451
The nucleus of the male gametangium initial is considerably
larger than is common in cases of vegetative mitosis (fig. 18). The
chromatin network of the resting nucleus is marked by a number of
knots mixed with broken fibrils (fig. 18). The chromatin knots
increase gradually in size in prophase and finally break up into 24
chromosomes (fig. 19). Up to this stage the nucleolus remains
without apparent change. When the chromosomes begin to be
arranged at the equatorial plate, the nuclear membrane becomes
contracted, and at the completion of the nuclear figure the decrease
of the diameter of the nucleus is remarkable (fig. 20). Two dis-
tinct centrosome-like structures now are present at metaphase.
While the nuclear membrane still persists, the chromosomes split
longitudinally and half of each chromosome proceeds to each pole
(fig. 22). The nucleus passes into telophase, two new daughter
nuclei are formed, and then the subsequent divisions occur. In the
second division the two nuclei may undergo mitotic changes simul-
taneously, both showing 24 chromosomes in prophase (fig. 23), or
one may proceed more rapidly than the other. Figs. 24 and 25
show the latter case; the nucleus of the upper cell is in prophase,
showing 24 chromosomes, and that of the lower cell is in metaphase.
In figs. 24 and 25, in spite of the apparent similarity in the size of
the lower cells, the difference in the size of their nuclei at metaphase
is remarkable. Sometimes the nucleus of the upper cell is far
behind that of the lower cell in dividing, so that, as in fig. 26, the
upper nucleus is in the resting condition while the lower one is in
anaphase. Fig. 27 shows the nucleus of the upper cell in meta-
phase, which passes to anaphase (fig. 28) and to telophase (fig. 29)
while that of the lower cell remains resting. When the filament has
reached the 3-celled stage mitosis in the three nuclei proceeds in
varying order. In fig. 30 is shown the case in which the nucleus
of the basal cell is more advanced, revealing 24 chromosomes in
prophase. The following figure shows the nucleus of the terminal
cell in advance and now in metaphase. In the next figure the
nucleus of the middle cell is already in anaphase.
At the 4-celled stage of the young gametangium, the nucleus in
prophase invariably shows 24 chromosomes (figs. 33, 34). At about
this stage the nucleus in division has almost the same size and
452 BOTANICAL GAZETTE [DECEMBER
aspect as the nuclei in vegetative filaments. In figs. 35 and 36 are
given anaphase and prophase of the vegetative division. Until
about the 4 or 5-celled stage the young gametangium consists of a
single row of cells, after which division also occurs perpendicular
(figs. 37, 48) to the direction of the axis of the gametangium, so that
there are two rows of cells. When the young gametangium has
reached the 8 or more-celled stage and consists of two rows of cells,
the nucleus in both the resting and dividing condition has neces-
sarily been forced to assume a somewhat irregular form so as to_
occupy the largest possible space, and it does not decrease much in
size in spite of the multiplied divisions and consequent diminution
of the cells of the gametangium (figs. 40, 41).
Another division perpendicular to the direction of the growth
of the gametangium occurs (figs. 42, 44), and the gametangium
becomes a structure composed of four rows of cells. The diminu-
tion in the size of the nucleus is now recognizable (figs. 43, 45)-
Although the chromosomes which appear in prophase are 24 in
number, their size has become remarkably reduced to about half
the diameter of those appearing in earlier mitoses. The diminution
may proceed still further during the divisions which multiply the
number of the cells in a tier. There now occurs the third and last
division perpendicular to the axis of growth of the gametangium
(fig. 50), resulting in a structure composed of eight rows of cells.
Even after the gametangium shows eight rows of cells, a number of
mitoses may occur that increase the number of cells in the rows
(figs. 46, 47, 48, 49), and during these mitoses there are always
24 chromosomes. These longitudinal divisions of the game-
tangium, as well as the transverse, are strictly simultaneous, but
they proceed at a nearly uniform rate, so that ultimately there is
formed the well known male gametangium of Culleria, which is
composed of eight rows of cells, each row made up of a varying
number of cells. The number of cells in a row may be even more
than 24, the cells of each row lying side by side with the cells of the
contiguous row. Each individual cell in the gametangium is 4
male gamete mother cell, within which a single male gamete is
formed.
The mother cell contains a single large nucleus situated in the
Ig12] YAMANOUCHI—CUTLERIA 453
center, and usually two plastids whose position varies. The
nucleus passes into a completely resting condition. Fig. 52 repre-
sents a cross-section of a male gametangium, each gamete mother
cell showing a red pigment spot in close association with the
nucleus. When the male gametes are mature within, a portion
of the free surface of the ‘
membrane of the mother cell
dissolves so as to leave a
small pore, through which
the gametes are discharged.
The cilia of the gametes first
protrude from the pore, keep
moving for a while, and then
all the contents emerge and
the male gamete is set free.
THE FEMALE GAMETANGIUM
Mature female gametangia.
—Female gametangia are
scattered over the whole sur-
face of the thallus, as in the
case of the male gametangia | e gee =
(figs. 5, 6, 7). The female Fic. 5.—Cutleria multifida: portion of a
gametangia are developed pane: Toe ‘ao
alone or are associated with developainit:,
hairs which appear upon the :
surface of the thallus long before the appearance of the gametangia :
As in the case of the male plants, the hair and gametangium origi-
nate from superficial cells of the thallus. —
The mature female gametangium consists of several tiers of
female gamete mother cells, the number of tiers varying from 4 to 7.
Each tier is composed of 4 or 8 mother cells, so that the output
of gametes from a single female gametangium fluctuates between 16
and 56. The mature female gamete in the free swimming condition
outside of the gametangium is oval (fig. 8, 0), and usually contains
more than 30 plastids. The anterior end of the body of the female
gamete is destitute of plastids and contains colorless granular
454 : BOTANICAL GAZETTE [DECEMBER
cytoplasm, thus indicating the existence of polarity in the distri-
bution of plastids. In association with one of the plastids, which
is situated near the periphery in the vicinity of the anterior end,
there is present ared pigment spot. Close to the pigment spot, two
cilia of unequal length are borne; the long one being directed toward
the anterior end, 1.5 times the long diameter of the gamete, and
the short one in the opposite direction about equal in length to the
Fics. 6, 7—Cutleria multifida: fig. 6, a filament bearing two female gametangia;
fig. 7, female gametangia near maturity; @ consists of 7 tiers of mother cells, and
b of 4 ti
diameter of the gamete. The long axis of the female gamete is
26.2@. The female gamete is actively motile when discharged,
- but after a while the movement becomes sluggish, the shape becomes
spherical (fig. 8, ¢), and the cilia are withdrawn.
Development of female gametangia.—Like the male gametangium,
the female gametangium arises from a superficial cell of the thallus.
One of the superficial cells begins to grow more rapidly than the
others (fig. 53) and a typical mitosis takes place, which gives rise
1912] YAMANOUCHI—CUTLERIA : 455
to a gametangium initial and a stalk cell. Sometimes a second or
third division is intercalated between the first division occurring
in the superficial cell and the formation of the gametangium initial,
and in this case the female gametangium, instead of having a stalk
of a single cell, has a stalk consisting of two (fig. 7, a) or three cells
(fig. 7,6). Or a number of divisions follow the first, so that the
superficial cell develops into a long filament and some cell of the
filament divides laterally to form e
a branch which becomes a game-
tangium initial (fig. 6).
The nucleus of the game-
tangium initial increases greatly
in size, as in the case of the male
gametangium initial. Init there
is contained a large number of
plastids. The chromatin nét-
work of the nucleus, which is
composed of irregular knots and
scanty fibrils during the resting
Stage, gradually increases in
chromatin content, and finally
there is established a prophase
fig. 54) containing 24 chromo- sketched fron living material; a, male
Somes and a single nucleolus. gamete; 6, female gamete; c, female
In metaphase the volume of the gamete which has become quiescent and
nucleus diminishes considerably ee
apogamously.
(fig. 55), when compared with
the previous stage, and centrosome-like structures appear at the
poles. While the nuclear figure is still intranuclear, the chromo-
Somes split longitudinally and half of each chromosome passes to
each pole (fig. 56). At telophase two daughter nuclei are formed, -
and no central spindle remains between them. The cell plate is
laid down by the cooperation of the vacuoles and rearrangement of
the cytoplasm (fig. 57). Each nucleus of the two cells grows in
size simultaneously during the resting condition (fig. 58) and then
the rates of the mitotic processes in these two nuclei diverge; the
upper nucleus enters prophase, showing 24 chromosomes (fig. 59),
456 BOTANICAL GAZETTE [DECEMBER
metaphase with two centrosome-like structures (fig. 60), ana-
phase (fig. 61), and reaches telophase (fig. 62) while the lower
nucleus still remains in the resting condition. Sometimes the lower
nucleus divides first, showing metaphase with two centrosome-like
structures (fig. 63) and anaphase (fig. 64) while the upper nucleus
rests.
In the young female gametangium, consisting of three cells, the
mitoses occur in varying order; sometimes the nucleus of the basal
cell divides first (figs. 65, 66), sometimes that of the upper cell (figs.
67, 68), and sometimes that of the middle cell (figs. 69, 70), and
during these divisions 24 chromosomes are always seen in ——
(figs. 65, 66, 69, 71).
Up to the 4-celled stage the female gametangium divides
transversely, and then a perpendicular division occurs (fig. 72), SO
that the gametangium consists of two rows of cells, after which
another longitudinal division (figs. 73, 78) immediately follows and
results in producing a gametangium of four rows of cells.
Mitosis in the gametangium of the 7—11-celled stage is not
simultaneous, but occurs at different times in different cells. The
nucleus in the middle cell may divide ahead of the others (figs. 74-
77, 79, 80, 83, 84), whose nuclei are either in the resting stage or in
prophase. The nucleus in prophase in any of these cells always
presents 24 chromosomes, and in metaphase two centrosome-like
structures are seen at the poles. It is remarkable that the chro-
matin knots or globules in the resting nucleus always lie quite
independent of one another, the chromatin fibrils being so scanty
that they are unable to connect them together.
In the young gametangia of the 10-18-celled stage, the mitoses
take place as in earlier stages (figs. 85-88); the prophase and the
polar view of metaphase show clearly that the number of chromo-
somes is 24. One striking feature as contrasted with the male
gametangia is that in the female gametangia the nuclear diminution
in size is not very great during the repeated divisions and conse-
quent multiplication of cells of the gametangia. Of course the
nucleus at the time of the first division in the female gametangium
is rather large, especially in prophase (fig. 54), and the nucleus in
the prophase of the division in the female gametangium of the 18-
soxal. YAMANOUCHI—CUTLERIA 457
celled stage is almost two-thirds of that diameter (fig. 87), but if
the nuclei in metaphase and in the resting condition are taken into
consideration, almost all of the cases in the gametangia from the
2-celled stage to 18-celled stage seem alike. The female gametan-
gium, consisting of four rows of cells, becomes mature (fig. 89), but
quite often each of the cells in the four rows divides again, so that
the gametangium consists of eight rows of cells (fig. go).
These numerous nuclear divisions are not simultaneous, but
follow in regular order, both those which are transverse to the axis
of the gametangium and those which are perpendicular to it, so
that the ultimate result is the well known female gametangium of
Cuileria, which is composed of four or eight rows of cells, each row
composed of 4-7 cells, the cells of each row lying almost exactly
opposite the cells of the neighboring row. Each individual cell
of the gametangium is a female gamete mother cell. The mother
cell contains a large nucleus either in the center or near the inner
wall (figs. 90,92). Plastids are crowded either near the inner wall
(fig. 91) or near the outer side (fig. 92), or lie scattered regularly
throughout the whole cytoplasm. The nucleus is in the resting
condition.
When the gametangium is mature, the whole contents of a
gamete mother cell become a single female gamete. A portion of
the free surface of the mother cell dissolves and forms a pore through
which the gamete is discharged. The slow process of discharging
the gametes is the same as in the case of the male gametes; first,
the cilia of the gametes appear outside the pore, keep waving for a
while, and then the female gamete is set free.
FERTILIZATION AND THE GERMINATION OF THE FERTILIZED FEMALE
GAMETES
The discharge of both male and female gametes occurs at almost
any time during the day and night. However, so far as the writer’s
experience goes, while he was making observations at half hour
intervals under the microscope, the majority of cases showed that
the discharge was most abundant at 5 A.M., and that it continues,
though gradually diminishing, until 7 a.m. and then ceases. Occa-
sionally there is some discharge at 11 A.M. and 5 P.M. The motile
458 BOTANICAL GAZETTE [DECEMBER
power of the male gametes continues for almost 20 hours, while that
of the female gametes is comparatively short, the longest period of
the swimming condition observed having been 2 hours, and the
shortest 5 minutes. Toward the end of the motile condition in
both male and female gametes, the movements become sluggish,
and then cilia are no longer recognizable, seemingly being withdrawn
or coalescing with part of the plasma membrane of the gamete body,
and finally the shape of the body becomes spherical. However,
in a number of cases gametes caught in the thallus of algae while
swimming between the slide and cover-glass remained active for
more than 24 hours, and then became spherical; when stained at
that time they showed the cilia still persisting and not coalescent
_ with the plasma membrane.
The union of male and female gametes and the subsequent
nuclear behavior were studied in material from artificial cultures.
A number of dishes were prepared containing either male or female
plants bearing mature gametangia. When the discharge of
gametes became abundant, the sea water of the dish containing
thousands of swarming male gametes was added to a dish contain-
ing vigorous female gametes. Then part of this mixture was
observed under the microscope in living condition and part was
fixed every 30 minutes for 24 hours, and then at 26, 28, 32, and 48
hours, and later, every 3 or 5 days up to 75 days. The following
description is based upon materi al obtained in this way.
The male gametes while swimming freely become attached to the
female gametes which are either sluggishly swimming or have come
to rest, but have not yet formed a cell wall. When the male gamete
becomes quiescent, before coming in contact with the female
gamete it withdraws its cilia and its shape becomes spherical.
The nucleus is full of chromatin which is clearly broken into 24
independent chromosomes. The nuclear membrane is very deli-
cate (fig. 94). When a male gamete has just become attached to the
female gamete, both gametes have very delicate plasma membranes.
The nucleus of the female gamete is at the center of the cell, as in
the resting condition (fig. 95).
Then the plasma membranes which lie between the cytoplasm
of the male and female gametes become obscure and the cytoplasm
1912] YAMANOUCHI—CUTLERIA 459
of the two gametes comes into direct contact. The male gamete can
be observed for a short time as a protuberance at the periphery
of the female gamete (fig. 95); however, sooner or later the pro-
tuberance is entirely absorbed or leveled down to the surface of the
now spherical female gamete. The male nucleus with 24 distinct
chromosomes proceeds toward the resting female nucleus (fig. 96);
it then proceeds still further (fig. 97) until it is close to the female
nucleus (figs. 98, 99). The male nucleus at this stage is surrounded
by a clear zone, which possibly means that the nucleus is carrying
with it a part of the male cytoplasm or a part of the female cyto-
plasm which had been lying in the path of the male nucleus. The
male nucleus now becomes closely applied to the female nucleus
(fig. 100). The chromatin of the male nucleus becomes closely
aggregated (fig. ror), and then begins to be finely alveolated (fig.
102), and finally becomes dispersed through the female nucleus
as irregular knots (fig. 103). Later the fusion nucleus contains
chromatin knots of various sizes and shapes, together with delicate,
irregular, discontinuous fibrils. A nucleolus which was present
in the female nucleus before the union still persists (fig. 104). The
fusion nucleus thus passes into a completely resting condition, in
which chromatin of male and female origin cannot be distinguished
from each other.
Returning to the previous stage, at the time of the union both
gametes are surrounded by plasma membranes only. At the time
of the entrance of the male nucleus into the female cytoplasm the
outermost layer of the plasma membrane is observed to change into
cell wall (fig. 96), which is very thin at first, but gradually increases
in thickness as fusion progresses, and is well organized by the time
the fusion nucleus reaches the resting condition.
The first segmentation division of the sporelings of the fertilized
gametes takes place 20-24 hours after the union of the gametes.
In prophase there appear 48 chromosomes, all of which seem alike
both in size and shape (fig. 106), and a single nucleolus persists.
At metaphase the chromosomes are arranged at the equatorial
Plate and two centrosome-like structures appear at the poles
(fig. to7), A comparison of the prophase and metaphase shows
that the volume of the nucleus is considerably diminished at the
460 _ BOTANICAL GAZETTE [DECEMBER
latter stage. The mitosis may take place before the sporeling
begins to elongate; but in the majority of cases the sporeling
elongates into a somewhat pear-shaped structure while its nucleus
is still in the resting state (fig. 108). Quite often the nucleus is
present at the elongated portion (fig. 109). The cell wall of the
elongated portion which is to become the holdfast is comparatively
thick.
The number of chromosomes at prophase (figs. 110, 111) and
seen in polar view at metaphase (fig. 114) is 48. The axis of the
figure is often perpendicular to the growing axis of the sporeling
(fig. 113). After telophase the sporeling is divided into two cells
(fig. 115). The nuclei of the two cells divide one after the other;
sometimes the lower nucleus increases more rapidly than the upper
(fig. 117), or the upper nucleus begins to divide first (figs. 116, 118-
120). Insporelings consisting of three cells, mitosis occurs in various _
order in the three nuclei; the nucleus of the basal cell may divide
first (figs. 121, 122), or the three nuclei may divide simultaneously
(fig. 123). The number of chromosomes appearing at.the prophase
(figs. 121, 123) is 48.
The fourth, fifth, and subsequent divisions, that occur continu-
ously for more than ten days, multiply the number of the cells of
the sporeling, resulting in the development of the upright columnar
form that grows standing upon the substratum, and then the
direction of growth becomes changed.
Before describing this change of growth which occurs in spore-
lings about ten days old, we shall note briefly the fate of the red
pigment that is conspicuous in the living gametes. As was stated
before, the red pigment is always associated with the plastid. A
part of the plastid becomes impregnated with some substance of a
deep orange color, which seems to disorganize instantly with the
death of the sporeling. The most interesting point is that the
cilia are attached to the pigment, and the red pigment is the only
structure within the sporeling that bears any close and direct
physical connection with the cilia. Moreover, the plastid that
bears the red pigment always lies near the nucleus. By the union
of male and female gametes the red pigment bearing plastid of the
male gamete is introduced into the female gamete and consequently
1912] YAMANOUCHI—CUTLERIA 461
two red pigment structures are always present in sporelings result-
ing from fertilization: a large red pigment spot is associated with a
large plastid of the female gamete, and a small red pigment spot
upon a small plastid is characteristic of the male gamete. Although
the plastid bearing the red pigment of the male gamete grows in
size after its introduction into the cytoplasm of the female gamete,
yet it seldom becomes equal in size. This difference in size of
the two pigment spots is maintained as far as the present
observation goes. Fig. 9 represents some of the stages in the
development of sporelings from the 1-celled to the 5-celled stage,
indicating the various positions of the two red pigments of
male and female origin. The red pigment was recognizable
even up'‘to the 16-celled stage, and beyond the 20-celled stage
it becomes hard to recognize, probably on account of the disin-
tegration of the coloring matters. It seems probable that the
red pigment is concerned with the motility of the gamete rather
than with fertilization.
As stated before, the sporelings develop continuously in one
direction, and as a consequence after about ten days there is pro-
duced a columnar structure standing upright upon the substratum,
and then the direction of the growth becomes changed. Cells of
the basal portion of the columnar sporeling divide laterally, instead
of in the direction of the axis of the growth, so that by repeated
cell division there is produced a flat expansion, the whole structure
of which might be well compared with a candlestick, the candle
being the column and the base the newly developed flat expansion.
The basal expansion is developed by the repeated periodic cell
divisions on the lateral margin, which causes a zonation like that
in Peyssonnelia; besides, the thallus is characterized by inter-
calary growth. Sporelings at about 20 days after fertilization are
shown in fig. 10, a. Later the upright column does not seem to
Stow much, only the basal expansion continuing to develop.
Sporelings 30 days old are shown in fig. 10, b. In 55 days old
sporelings, the growth of the column has ceased, and it remains
small, hardly recognizable to the naked eye, while the basal expan-
sion reaches a considerably larger size and becomes well fitted to
flourish as an independent creeping structure (fig. 10, ¢, d).
462 BOTANICAL GAZETTE [DECEMBER
Fic. 9.—Cutleria multifida: normal sporelings sketched from living material;
a-e, saseMiee stage; = two-celled stage; j and k, three-celled stage; /, four-celled
Stage; m, five-celled stage; nucleus not recognizable in living material; the two
pigment spots saeseieat with plastids are of maternal and paternal origin; the small
pigment spot introduced by the male — ~ large one by - female gamete; the
plastid that bears the small red pigm after its introduction
into the female gamete.
SS ae YAMANOUCHI—CUTLERIA — 463
464 BOTANICAL GAZETTE [DECEMBER
The similarity of the habit of this creeping expansion of the
thallus to that of Aglaozonia in nature is striking. The material of
Aglaozonia collected fresh from Posilipo and Nisida, which has
grown creeping on a sea-urchin’s shell or on the rock, showed a
number of forms in various stage of development. If the creeping
expansion of the thallus obtained in cultures is compared with
Aglaozonia of similar size as it occurs in nature, it is hard to find
any difference in their appearance. Not only the zonal growth and
occasional intercalary growth of the thallus is alike in these two
forms, but also the cell structure as seen in sections under the micro-
scope is remarkably similar in the two forms. The nuclei of the
thallus obtained in culture contains 48 chromosomes, and the same
number is present in A glaozonia as it occurs in nature.
The author’s cultures of the thallus expansion, the Aglaozonia
form of Cuéleria, were not continued up to the stage of producing
reproductive organs.
GERMINATION OF THE UNFERTILIZED FEMALE GAMETES
As was described before, the female gametes after their escape
from the gametangia may swim for as long a time as 2 hours, oF
for as short a time as 5 minutes. When the motion becomes slug-
gish, the body becomes spherical, the plastids which have hitherto
occupied the more posterior portion of the body become irregularly
scattered throughout, and finally the cilia are either withdrawn
or they coalesce with the plasma membrane as the movement ceases.
If the female gametes in this condition are kept with no addition
of the male gametes, they remain dormant for a considerable time.
The female gamete left in this condition at length shows a change
in the outermost layer of the plasma membrane that is in direct
contact with sea water, the change resulting in the development of 4
cell wall, thin at first, and then increasing in thickness. The
nucleus is in the resting condition (fig. 124). Not infrequently
it is observed that the female gamete, now inclosed within a cell
wall, has an elongation at a part of the body where the cell wall is
thickened (figs. 125, 8, d).
This unfertilized female gamete commences to divide 24-28
hours after it has assumed the quiescent condition. The mitosis
1912] YAMANOUCHI—CUTLERIA 465
occurs frequently without any elongation of the sporeling. When
the nucleus is in prophase there seems to be no departure from the
typical mitosis characteristic of Cwulleria, the division being per-
fectly normal. The number of chromosomes appearing in prophase
is 24 (fig. 126). At metaphase two centrosome-like structures
appear at the poles (fig. 127), and the number of chromosomes is
clearly 24 (fig. 128). Some-
times the metaphase is
reached while a part of the
sporeling is elongating (fig.
130). The chromosomes
split longitudinally and half
of each chromosome passes
to each pole (fig. 131). The
axis of the first mitotic figure
may be either longitudinal or
transverse to the axis of the
sporeling (figs. 132, 133).
After telophase two new
daughter nuclei are formed
(fig. 134). In the sporeling
of the unfertilized female
gamete beautiful radiations
ate closely associated with
the upper nucleus (fig. 135),
but they are of short dura-
tion, and disappear com-
pletely when the nucleus
passes into prophase (fig. 136).
Fic. 11.—Cutleria multifida: apogamous
sporelings: a, 30 days after germination; 8,
50 days after germination; d, 75 days after
germination (d represents a part of a spore-
ling under the same magnification as a and 6,
and the whole of the apoeenne > is shown in ¢);
th in devel €lop-
ment. as s compared with the normal] ones, and
assume massive forms at first and then the
flat zonal expansion like the normal ones.
When the upper nucleus is in
metaphase (fig. 137), the lower nucleus enters into prophase.
Both the metaphase, viewed from pole (fig. 137), and the prophase
show 24 chromosomes. One peculiarity observed is the appearance
of elongated chromosomes in the upper nucleus of a 2-celled spore-
ling during prophase (fig. 138). The division of the upper and
lower nuclei is not simultaneous; sometimes the upper nucleus
is far ahead of the lower, so that the former is in late telophase
466 BOTANICAL GAZETTE [DECEMBER
while the latter is in metaphase (fig. 140), or the upper is left
behind in the resting state while the lower is in anaphase (fig. 139).
In sporelings of the 3-celled stage the lowest nucleus may divide (figs.
IAI, 143) in advance of the rest, or the middle one may divide first
(fig. 142).
Cell divisions continue up to a 12~22-celled stage (figs. 144-
146). As seen in fig. 146, the axis of growth does not continue in
one direction, as in normal fertilized sporelings, but the structure
is branched. After repeated divisions there is formed a some-
what upright structure, not columnar, but rather laterally pro-
duced and in irregularly massed lumps (fig. 11, a). This upright
structure with a lateral uneven mass consisting of about 35
cells is produced in 30 days. The irregular nature of this struc-
ture is still seen in sporelings of 50 days (fig. 11, 0). Some of the
irregular appendages of the structure which happen to be in con-
tact with the substratum become creeping expansions and later
become the main part of the sporeling.
And thus the unfertilized sporelings after 75 days develop into
the thalloid creeping structure (figs. 11, c, d), and the product
bears some resemblance to the product of the sporeling resulting
from a fertilized gamete. Comparing these two products, the
points of marked difference are as follows: (1) the first segmenta-
tion division occurs 6 hours later than in the normal sporeling;
(2) the subsequent growth of these sporelings is very much slower
than in normal sporelings; (3) unfertilized sporelings are char-
acterized by developing into irregular masses at first, and even
after they have assumed the expanded structure, they still show @
_ tendency to form massed appendages; (4) the number of chromo-
somes is unchanged, the sporeling from the unfertilized gamete
containing only 24 chromosomes.
Aglaozonia reptans
MITOSIS IN THE VEGETATIVE CELLS
Aglaozonia reptans Crouan has a creeping crustaceous habit
on rock or sea-urchin’s shells, attached by rhizoidal holdfasts from
the superficial layer of the ventral surface. The superficial layer
consisting of small cells of equal size is either single (fig. 147) °F
Ig12] YAMANOUCHI—CUTLERIA 467
double (fig. 148) on the dorsal surface, and between the dorsal
and ventral superficial layers there are two or three layers of
parenchyma-like cells of huge size. Any cells in the superficial
layer of the dorsal surface of young A ——— are favorable for
studying vegetative mitosis.
The vegetative mitosis was studied chiefly in the nucleus of the
superficial cells of Aglaozonia. The main features of the division
are similar to those of Culeria, and consequently a detailed account
and figures will be omitted at this time, but a few points should be
noted.
The size of the nucleus in the superficial cells is either about the
same as that of the plastids within the cell or is even smaller.
When the nucleus is in the resting state, the chromatin network is
remarkably similar to that of Cuileria, the chromatin knots being a
conspicuous feature, though few in number, while the fibrils are
very scanty and broken. One noteworthy feature not common in
the case of Culeria, but of general occurrence in A glaozonia, is that
deeply stained granules about the size of the chromatin knots
within the nucleus are present around and close to the membrane
outside the nucleus. These granules become faintly stained and
evidently diminished in size during the mitotic phase within the
nucleus, and they entirely disappear while the nucleus is still in
prophase. It seems probable that the granules may be material
allied to chromatin that might have passed into the nucleus, thus
contributing to the formation of chromosomes.
The chromosomes appearing in prophase are 48 in number, and
their form is in nothing different from those of Cudleria.
FORMATION OF ZOOSPORANGIA
Zoosporangia are produced on the upper surface of the thallus.
When living Aglaozonia is viewed from above, the groups of zoo-
sporangia are distinguished by patches of darker color, contrast-
ing sharply with the light brownish olive color of the sterile
portion. These patches are composed of hundreds of thousands of
zoosporangia which are produced in palisade arrangement upon
the thallus. The details of the origin of the zoosporangium are as
follows: a superficial cell of the thallus elongates slightly and
e
468 ‘BOTANICAL GAZETTE [DECEMBER
divides, giving rise to two cells, the upper one of which becomes a
zoospore mother cell, and the lower remains as a stalk cell (figs. 148,
149). The process occurs in a number of superficial cells lying
side by side, and as a consequence zoospore mother cells are pro-
duced in great numbers, lying close together and parallel. When
the superficial layers are double, the cells in the outer layer elongate
Fic. 12.—Aglaozonia reptans: portion of a thallus with numerous filaments; the
filament usually consists of two cells, but in the present exceptional case they are
made up of a varying number of cells (3-7), and their terminal cells are zoospore
mother cells.
and directly become the mother cells (fig. 150). Not infrequently
it is to be observed that several cell divisions take place in the super-
ficial cells, so that a single superficial cell develops into a slender
filament consisting of 3~7 cells, and the terminal one becomes the
mother: cell (fig. 12). The zoospore mother cell is at first like an
ordinary superficial cell, with length and breadth about equal
1912] YAMANOUCHI—CUTLERIA 469
(fig. 151), but sooner or later the cell begins to elongate upward
until its length becomes three times its width, the top being slightly
swollen and the base narrowed. The nucleus lies either in the center
or a little above the middle of the cell. The cytoplasm is full of
vacuoles of various sizes, and plastids are quite numerous.
The nucleus in the resting condition contains a moderate amount
of chromatin network and a nucleolus. The network is composed
of very small chromatin knots and irregular fibrils (fig. 152); the
proportionate amounts of the knots and fibrils seem to interchange
at this stage (fig. 153). In iron-hematoxylin preparations dark
kinoplasm surrounds the nucleus (figs. 151, 152). The amount of
the chromatin gradually increases and the general tendency is
for the broken fibrils to become thicker and continuous, transform-
ing the knots into the fibrils (fig. 154). At this time, a single
(figs. 154, 158) or double (figs. 155, 157) centrosome-like structure
with radiations is recognizable at the poles.
Stronger and more continuous threads are then established by
the rearrangement of the knots and fibrils. The chromatin net-
work, which is composed of a number of broken threads of various
lengths and thicknesses, now entirely devoid of former knots, is
not very great in amount. For a while the broken threads are
seen running for quite a distance either close to the membrane or
traversing the cavity (fig. 159, 160). Then the threads gradually
become more and more uniform in thickness and are transformed
into somewhat regularly arranged loops, centered at a certain
part of the cavity {fig. 161). This transformation represents the
beginning of the synaptic stage.
This bunch of loops may be in regular arrangement (fig. 162) or
adhering at the base to the membrane and diverging upward so that
each loop passes along the membrane (fig. 164); or often each loop
of the bunch differs in compactness of structure, and consequently
some loops are short while others extend for some distance (fig. 165).
In any event, a cross-section at these stages shows that the number
of the cut ends of the arms of all the loops is about 48 (fig. 166).
These loops now shorten considerably (fig. 167) and some of them
are soon detached from the main group and form paired chromo-
somes (figs. 168, 169), and finally there are established 24 bivalent
47° BOTANICAL GAZETTE [DECEMBER
chromosomes, each derived from one of the loops (fig. 170). These
24 bivalent chromosomes gather near the center of the nucleus
(fig. 171), and then are afranged at the equatorial plate (fig. 172),
when the number is clearly counted in the polar view (fig. 173).
Then each of the chromosomes splits longitudinally (fig. 174) and
half of each proceeds to each pole of the spindle and there again the
polar view of the anaphase clearly shows 24 chromosomes (fig.
175). The chromosomes grouped at the poles now become closely
applied to one another (figs. 176, 177) and finally there are organized
two daughter nuclei (fig. 178). Up to this phase a kinoplasmic
mass persists, either surrounding the nucleus or near the pole of
the spindle, but centrosome-like structures are recognizable only
at metaphase.
The two newly formed daughter nuclei now increase in size.
Their relative position within the cell is variable; sometimes they
are wide apart (fig. 180), and often they lie for a while in close
contact (fig. 182). The centrosome-like structure with radiations
is present, associated with the two resting nuclei (fig. 180). These
two nuclei may divide simultaneously or in succession (figs. 183-
185). The number of chromosomes present during this division
is also 24, and with this reduced number the nuclei pass into telo-
phase (figs. 186-188). The third division follows the second after
a short rest, 24 chromosomes being present at metaphase (fig. 189).
As a result of the third division there are produced eight nuclei
within the mother cell (fig. 190).
It is interesting to note the relative position of the axes of the
mitoses that occurred within the mother cell. Only a few of the
cases are represented in fig. 13. As the figures clearly show, the
axis of the first mitotic figure is either in the direction of the long
axis of the mother cell, or slightly oblique to the axis; in some cases
the axis is still more oblique, until finally the axis of the figure is
perpendicular to the long axis of the cell. In the second mitosis,
considering the cases wheré the two mitotic figures occur at the same
time, the relative position, as shown in figures, shows all possible
directions of the axes. The same is true of the third nuclear divi-
sion. All of these zoospore mother cells show no polarity in i Fee
to the axis of the mitotic figures.
1912] YAM ANOUCHI—CUTLERIA
Fic. 13.—Aglaozonia reptans: zoospore mother cells in various stages of develop-
monees, first row, the nuclear figures are in metaphase of the first division and lie in
Varlous positions in relation to the axis of the mother cell; second row, metaphase of
the second division; third row, two at the right in anaphase and telophase of the
eecond division; third row, two at the right in anaphase and telophase of the second
division, two at the left in 8-nucleate stage, and the rest in metaphase of the second
division; fourth row, various arrangements of zoospores formed within the mother
cells, the two at the left are the two sections of a single mother cell which contains
32 Zoospores, and in the rest 8 zoospores are present.
472 BOTANICAL GAZETTE [DECEMBER
The plastids in the zoospore mother cell seem always to be
multiplying in number during these nuclear divisions. When the
nucleus is in prophase of the first division, the surrounding cyto-
plasm contains a number of plastids in various stages (fig. 191); the
number is increased at the time of the 4-nucleate stage (fig. 192),
and at the 8-nucleate stage the cell is filled completely with the
plastids (fig. 193). It seems probable that this gradual multi-
plication of plastids may be one of the reasons why the zoospore
mother cell constantly increases in size up to the formation of the
zoospores, when the length of the mother cell becomes six times its
width
When the zoospore mother cell has reached the 8-nucleate
stage, cleavage furrows generally occur in the cytoplasm, and divide
the contents of the mother cell into 8 zoospore primordia (Anlagen).
Not infrequently, however, one or two more divisions occur after
the third, and as a consequence there are produced 16 or 32 nuclei,
and in those cases 16 or 32 zoospores are formed (fig. 13).
The mechanism of the cleavage of the cytoplasm within the
mother cellin the formation of the zoospores is noteworthy. The
plastids at this time are arranged mostly near the cell membrane,
and the central part of the cell is occupied by the vacuolated cyto-
plasm (fig. 194). The nucleus lies either near the periphery or in the
midst of the cytoplasm. There is first a movement of the nuclei,
and this is followed by a movement of the plastids; that is, the
8 nuclei are distributed to certain portions, not very close to the
periphery, and then a number of the plastids move toward one of
the nuclei as a center and surround it (fig. 195). Then there begins
the separation of the Hautschicht from the cell wall, and at the same
time cleavage furrows appear in the cytoplasm between the nuclei;
the formation of the furrow is initiated by small vacuoles arranged
in a cleavage line, which unite afterward and break up, leaving
the furrow in their places (fig. 196). As the result of the process
of the cleavage furrow, there are produced free independent zoospore
primordia packed close together within the mother cell (figs. 198,
199). The relative position of the zoospores thus produced is
determined by the position the nuclei had occupied before the
cleavage began. Some of them are shown in fig. 13.
1912] YAMANOUCHI—CUTLERIA 473
During the development of the zoospore mother cell, while
these nuclear divisions have been taking place, the cell wall remains
apparently unchanged, except at the top of the mother cell, where
there has been a gradual increase in thickness, which culminates
at the time of cleavage. As the
zoospore primordia are com-
pletely formed, the top of the
cell wall begins to swell (fig.
200), then disintegrates into
lamellae, with lacunae between.
them (figs. 201, 202). Finally
the disintegrating lamellae of
the cell wall become completely
disorganized, so that a pore is
formed at the top, and through
this the zoospores escape after
maturity.
The zoospore in free swim-
ming condition is oval (fig. 14, a),
and usually contains more than
20 plastids. Associated with
one of the plastids, which lie
Inside the plasma membrane,
there is a red pigment spot, in
Close association with which two
cilia of different lengths are at-
tached, the longer one being
directed toward the anterior
end, about three times the
length of the zoospore, and a
short one extending in the oppo-
site direction about one and one-
third the length of the zoospore.
ZOO-
Fic. 14.—Aglaozonia reptans:
spores sketched from living material; a,
in free swimming condition; a’, sna
ning to be quiescent and splenic: @”,in
quiescent condition; the size varies ac-
cording to the number of nuclear divi-
sions within the mother cell; a,a’,and a”
are the products of three divisions (out-
put of 8 zoospores); 6, from four divisions
(output of 16 zoospores); c, from five
divisions (output of 32 zoospores).
The length of the zoospore is
a 5 # when the output of the zoospores in a cell is 8 (figs. 14, a’,
a’), 18.7 » when the output is 16 (fig. 14, 6), and 10.5 # when the
Output is 32 (fig. 14, c).
474 BOTANICAL GAZETTE [DECEMBER
GERMINATION OF THE ZOOSPORE
_ The duration of the motile condition of the zoospores varies;
some ceased to be motile within 10 minutes, while others were still
moving after more than 90 minutes; but in any case, when the
zoospore becomes sluggish, the body gradually becomes spherical |
and the cilia are withdrawn or become coalescent with the plasma
membrane.
About two hours after the quiescence of the zoospore, the
outermost layer of the plasma membrane becomes changed into a
delicate cell wall. The nucleus at this time is in the resting condi-
tion, with a centrosome-like structure and radiations near the
nuclear membrane (fig. 203). This condition remains unchanged
during the next 20 hours (fig. 204). The presence of centrosome-
_ like structures and radiations is not a definite feature; at about 24
hours after quiescence they may (figs. 206, 207) or may not be
visible (figs. 205, 208).
The first segmentation division of the germinating zoospore
takes place 24 hours after its quiescence. The nucleus enters
prophase either at the center of the cell (fig. 209) or in its elongated
part (fig. 210), and when the chromosomes are arranged at the
equatorial plate (figs. 211, 213), two centrosome-like structures
are present at the poles. The polar view of the metaphase shows
distinctly 24 chromosomes (figs. 212, 214). Each of the chromo-
somes divides longitudinally and half of each passes to each pole
(fig. 215). The second mitosis in these two nuclei may occur in
succession (figs. 217-221) or simultaneously (fig. 222), but in either
case 24 chromosomes can be counted at prophase and in polat
view of metaphase.
In the zoosporelings consisting of three cells the three nuclei
divide in various order (figs. 224, 225), and in prophase of any
nucleus 24 chromosomes are present. In the further nucleat
divisions in the development of the zoosporelings the same numbet
of chromosomes is counted. This young sporeling after a multitude —
of cell divisions (figs. 226-228) develops into a long filamentous
structure instead of a stout column. The product at about the
end of 20 days after germination is shown in fig. 15, a. In habit
the sporeling is very like the young filamentous stage of Cutleria.
.
1912]
YAMANOUCHI—CUTLERIA
475
Later this filament does not continue in the upward direction, but
there appears a new lateral structure near the basal orn of the
primary filament, and the
whole structure clings to the
substratum with rhizoids
which grow from the base;
_ thus, contrary to the behavior
of the fertilized gamete of
Culleria, basal expansions
that creep flat upon the sub-
Stratum are never found.
The plant at 30 days is illus-
trated in fig. 15, 6, which
resembles the young Culleria
as found in nature.
The new structure thus
initiated laterally from the
basal region of the primary
filament grows in such a way
that it finally meets the other
side of the primary filament
So as to form a funnel which
is expanded upward and nar-
rowly constricted downward.
Upon the expanded upper
margin of this funnel-shaped
_ Structure delicate hairs begin ,
togrow. Thisstageis reached ‘/
in about 40 days (fig. 15, c).
These funnel-shaped _ struc-
tures obtained in the artifi-
cial culture present a striking
Tesemblance to the young
plants of Cutleria in nature
as they occur in tufts on the
rock or on shells.
Fic. 15.—Aglaozonia reptans: zoospore-
lings; a, 20 days after germination; 6, 30
days after germination; c, 40 days after
germination; the sporelings are filamentous
in primary growth as shown in a, then
gradually assume the funnel-shape shown
in b and c, this shape being characteristic of
the young stage of Cuéleria in nature.
One difference is that the young plant of
Culleria in nature, at the same stage as the cultures in the
476 BOTANICAL GAZETTE [DECEMBER
laboratory, is furnished with a luxurious display of long beautiful
hairs on the margin of its furinel-shaped thallus, while such a hairy
growth has not yet been seen in cultures. It must be admitted,
however, that there is a difference between conditions in nature
and in cultures which may account for the difference in this
character; the young plant of Cuileria is found on the rock at a
depth of 1-5 meters, while the culture was kept in a tank where
the water was never deeper than 6-8 inches. Intensity of light,
temperature of water, its pressure, its movement, and other factors
may be quite different, and yet in spite of such a difference of
external environment, the zoosporelings of Aglaozonia developed
into erect structures of funnel-shape as in the young Cuileria
plants, and fundamentally different from the flat creeping expan-
sion habit of both parent forms and of the plants resulting from
fertilized female gametes of Cuileria.
The young plants of Cutleria and the product of the zoospore-
lings of Aglaozonia in culture show not only the common habit in
their development and similarity in their outer morphological
characters, but also a similar cell structure, similar nuclear condi-
tions, and the same number of chromosomes.
Discussion of cytological phenomena
THE ORIGIN OF UNIVALENT CHROMOSOMES
The chief constituents of the resting nucleus of Cudleria and
Aglaozonia are the network and nucleolus. The network is com-
posed of two parts, granules and irregular fibrils in varying pro-
portions. The granules are of different sizes and some of them are
connected by very slender, irregular fibrils, or lie isolated usually
near the nuclear membrane. The number of granules in the nucleus
quite often, though not always, corresponds more or less to the
number of chromosomes. The granules may be extremely small,
but the preparations never fail to show their presence. Both
granules and fibrils consist of chromatin.
As a rule, there is only one nucleolus, and it lies quite free from
the nuclear network, with which it shows no visible physical con-
nection. Concerning the morphological function of the nucleolus
in algae, STRASBURGER (55) 57) published the view that the sub-
1912] YAMANOUCHI—CUTLERIA 477
stance of the nucleolus is utilized for spindle formation, the conclu-
sion being drawn from the fact that the nucleolus disappears partly
or completely immediately preceding the formation of the spindle.
WI1L1AMs (66) in his study of Dictyota accepted this view. STRAs-
BURGER (53) had held the opinion that the nucleolus was reserve
material serving to build up the chromosomes, and this view was
followed by SwIncLE (61) on Stypocaulon and by MortieR (32)
on Dictyota. The view that the chromosomes are formed directly
from the nucleolus was supported by TANGL (62), MEUNTIER (29),
Mott (30), Decacny (10), HENNEGUY (19), VAN WISSELINGH
(67-69), Bercus (3), Karsten (22), and TRONDLE (64) in their
studies of Spirogyra, by WOLFE (70) on Nemalion, by Lewis (27) on
Griffithsia, and by SvepDELIus (60) on Delesseria. These investiga-
tions differ greatly in regard to exactness and details. In some of |
these papers views are expressed with adequate illustrations, but
often the illustrations and text are quite contradictory, and fre-
quently the figures would afford better support to some other
interpretation. In their statements, however, these authors seem
to agree that some or all of the chromosomes are organized directly
from the material of the nucleolus, which in this way either may
be used up partly or even entirely.
A fourth opinion is that the chromosomes arise exclusively
from the chromatin network, the nucleolus taking no direct part
in their development. Fucus illustrates the situation. The
Plates accompanying the studies on Fucus by STRASBURGER (56),
and by FARMER and WILLIAMS (15) show this situation, and more
details have been furnished by the present author (73). Polysi-
phonia (YAMANoUCHI 71), Corallina (Davis 8, and a forthcoming
Paper by the author), Zanardinia (YAMANOUCHI 76), as well as
Cutleria and Aglaozonia, present a similar situation.
THE ORIGIN OF BIVALENT CHROMOSOMES
Contrasted with the formation of univalent chromosomes in
typical mitosis, the origin of bivalent chromogpmes is rather com-
plex. As already described, in the resting nucleus of the zoospore
mother cell of Aglaozonia the chromatin network is composed of
granules and fibrils. While in typical mitosis the network finally
478 BOTANICAL GAZETTE [DECEMBER
becomes transformed into isolated individual chromosomes, the
granules and fibrils being entirely used up in the formation, in the
reduction mitosis the granular parts become transformed into
fibrils, and consequently during the presynaptic stage there are
only thread structures within the nucleus. These chromatin
threads, at their beginning irregularly thickened and branched,
become much evener, and the transformation continues until long
continuous threads are formed, which run freely throughout the
cavity. The threads thus formed, from the beginning of their
transformation to their completion as continuous structures, have a
single nature. Entering the synaptic condition, the single threads
then shorten and thicken, and become either eccentrically grouped
as a loose tangled mass at one side of the nuclear cavity, or are
variously scattered all over the membrane. The threads eventually
form loops by repeated folding. The number of loopsis 24. Each
loop folds together at its bent end so that the bent arms come into
contact with each other in the culmination of synapsis. As they
emerge from synapsis, there are present 24 bivalent chromosomes,
which become detached from the nuclear membrane, moving toward
various parts of the nuclear cavity.
The relationship of the chromatin threads in prophase, the loops
in synapsis, and the bivalent chromosomes of postsynapsis have
been clearly traced. A pair of bivalent chromosomes corresponds
to one of the loops in synapsis, the loop being formed by a folding
back of the chromatin thread, so that a loop in synapsis should be
considered as composed of two sporophytic chromosomes associated
end to end. The two elements of the bivalent chromosomes
separate from each other at the metaphase of the first reduction
division, thus effecting what may be regarded as a qualitative
reduction.
The origin and behavior of bivalent chromosomes as described
for Fucus (73) and Zanardinia (76) agree perfectly in essentials
with the present account of Aglaozonia. For example, figs. 161,
162, and 172, illustrating looping threads in synapsis and chromo-
somes in late prophase in the zoospore mother cell of Aglaozonia,
when compared with figs. 43, 44, and 49 illustrating similar stages
of Fucus (73), demonstrate at once their similarities.
1912] YAMANOUCHI—CUTLERIA 479
Disregarding many points which may differ in particulars, the
case of Aglaozonia, in which bivalent chromosomes in seemingly
reduced number have originated by the folding back of sporophytic
chromosomes united end to end, will agree in essentials with obser-
vations made by different authors on various forms, for example,
by Farmer and Moore (13, 14), SCHAFFNER (52), and MortieR ~
(34) on Lilium, by StRasBURGER (58) on Galtonia, and by one
group of zoologists, such as VON Ratu (37) on Gryllotalpa, RUCKERT
(41) on copepods, and Montcomery (31) on Peripatus.
In general, while the method of forming bivalent chromosomes
by the end to end fusion of sporophytic chromosomes or méta-
syndése, as GREGOIRE (17) calls it, occurs in Fucus, Zanardinia,
Aglaozonia, and other forms, there is also another method by side
to side fusion, or parasyndése, in Polysiphonia (71), Nephrodium
(72), Osmunda (75), and various other forms, such as Lilium
(Grécorre 16, Bercus 2, ALLEN 1), Allium (BERGHS 2), Tril-
lium (GréGorrE 16), and Drosera (ROSENBERG 40). From these
observations it is evident that in the former class there is no duality
in the formation of thread structures (Jeptoténes) from the resting
nucleus, and therefore in synapsis the two bent arms of a single
loop come into close association; and in the latter class, a duality
is present at the time of the beginning of the thread structures
(Jeptoténes), and the two independent members of the duality come
into contact during synapsis. In both classes, each of the two
elements of the bivalent chromosome is derived from a single
sporophytic chromosome, and the two elements separate in the
first division. It seems highly probable that there are two distinct
types of arrangement of sporophytic chromosomes at synapsis
in plant cells.
POLAR ORGANIZATION
Views on the polar organization of plant cells are conflicting.
Some of the algae present clear evidence of such polarity, the best
Known examples being Stypocaulon and Sphacelaria (61), which
have a center in the form of an aster with a centrosome at the side
of the resting nucleus of the apical cell. The centrosome is said
to divide previous. to each mitosis, to establish the poles of the
spindle. A similar centrosome with radiations is present in the
480 BOTANICAL GAZETTE [DECEMBER
tetraspore mother cell of Dictyota (32, 66). Other algae, such as
Corallina (8), Fucus (15, 56, 73), Polysiphonia (71), show highly
advanced centrospheres at the poles of the spindle; but investigators
claim that in Corallina and Polysiphonia they appear simultaneously
at the two poles during prophase, culminate at metaphase, and
disappear at anaphase or telophase; and in Fucus one of them
appears before the other and they disappear at telophase; only
as rare cases they remain recognizable at the side of the resting
nucleus. Thus, so far as present knowledge goes, the persistent
continuity of polar organization in algae cells has not been demon-
strated through successive cell generations.
The subject of polar organization has received especial atten-
tion in Harver’s studies on mildews, especially Phyllactinia (18).
In this form, the “central body” lies within the membrane of the
resting nucleus, and it is connected with chromatin strands so as
to give polarity to the nucleus. The poles of the spindle are
formed by division of the central body. Harper believes in the
permanence of this structure from mitosis to mitosis, and in the
persistence of its connection with chromatin.
The studies of recent years on the cells of pteridophytes and
spermatophytes have failed to support certain claims for the pres-
ence of centrosomes and have indicated that their cells are without
visible polar organization. Marquette (28) published the view
that the presence of polarity in the leaf cell of Isoetes is manifested
by a large starch-containing body that lies closely pressed against
the side of the nucleus. Previous to nuclear division, according
to Marquette, the polar structure divides, and during mitosis
the structure persists up to telophase, and finally one of them
remains at the side of the newly formed daughter nucleus, and a
similar constriction division occurs in the structure previous to the
next nuclear division. He also found a polar organization of the
spore mother cell of Marsilia, in the form of aggregated starch
grains, conspicuous at the time of synapsis, but disappearing Just
before the formation of the first spindle; the organization is of
very short duration, not continuing throughout the mitosis.
In Cuileria and Aglaozonia, polar organization is manifested
by the appearance of centrosome-like structures with or without
1912] YAMANOUCHI—CUTLERIA 481
radiations, always only at metaphase, and as a rule completely
disappearing at telophase. It may be found that polarity does
not depend in all cases upon the presence of permanent protoplasmic
structures of recognizable size or upon such morphological differ-
entiation as to rank as organs of the cell. There may possibly be
polarity at times without visible protoplasmic organization, but
so far as the visible organization of the cell is concerned, there seems
to be no permanent polar organization in the cells of Cutleria and
Aglaozonia. The transient polar organization is formed de novo
at each mitosis in every possible position about the nucleus. The
variability of the polar axis of the mitotic figure demonstrates
the feature (fig. 13).
Zoospores and gametes of algae invariably present a conspicu-
ous polarity in that their cilia are situated at one end or at a definite
point on the side, the point of insertion being devoid of plastids.
The most vital problem of zoospore and gamete formation is whether
the polar organization of these cells arises de novo at the time of
development or is handed down from the succession of the cells that
are their progenitors. STRASBURGER (57), from his studies of the
zoospores of Oedogonium, Cladophora, and Vaucheria, decided
that the cilia bearing organ, the blepharoplast, arises in the
plasma membrane (Hautschicht), the nucleus lying in close associa-
tion at the time of its formation. Morrier (33) later described a
similar origin of the blepharoplast in Chara. Davis’ work on
Derbesia (9) showed that the blepharoplast is developed at the
plasma membrane in the form of a ring that has been organized
by the side by side union of numerous granules arranged in a circle.
The marked polarity is manifested after the appearance of the
granules.
The details of the organization of zoospores and gametes of
Cutleria and Aglaozonia have not been given in this account because
the subject will be dealt with in a special paper treating of the ori-
gin of motile sperms or spores of algae, such as Fucus, Zanardinia,
Ectocarpus, and of some green algae, so that a brief account will
be sufficient for the present consideration of polarity.
In the zoospore mother cell stage, which is usually reached at
the 8-nucleate stage of the zoosporangium, cleavage furrows start
482 BOTANICAL GAZETTE [CECEMBER
from the periphery and cut into the protoplasm in the form of
curved and branching furrows. Finally, the protoplast within
the sporangium becomes divided into approximately equal masses,
each of which contains a single nucleus. These masses are zoospore
primordia, and each develops into a uninucleate zoospore. The
nucleus lies first at the center of the zoospore primordium, with
plastids lying near the periphery of the cell. The polarity of the
cell is clearly established when the nucleus moves toward the
peripheral region of the cell, displacing all the plastids in the
vicinity, except one which remains near the nucleus. At this time
a small granule can be seen lying in the plasma membrane near
the nucleus. This granule becomes the blepharoplast, and in a
part of the body of the plastid remaining near the nucleus there is
later developed a red pigment which makes it look as if the cilia
had arisen from the red pigment.
Thus the polarity of the zoospore is manifested only after the
organization of the blepharoplast and red pigment spot in the
plastid. Again, after its quiescence, the exhibition of polarity is
lost until either the segmentation of the nucleus or the elongation
of the cell wall begins.
ALTERNATION OF GENERATIONS
Since the classical investigations of HorMEISTER (20), it has
been universally recognized that the Archegoniatae are. char-
acterized by a definite alternation of generations. In this group
there are two regularly alternating generations, one bearing sexual
reproductive organs and the other producing spores. In sharp
contrast to the unanimous agreement in regard to the existence of
an alternation of generations in the Archegoniatae, there is 4
lively contest of contradictory views as to the alternation of
generations in the thallophytes. The thallophytes being a loose
assemblage of widely diversified types, and investigations on their life
histories being far from numerous enough to permit of any generaliza-
tion, some still question whether a regular alternation of definitely
established generations exists in the group, and if it exists, whether
it is to be regarded as homologous or antithetic.
1912] YAMANOUCHI—CUTLERIA 483
Perhaps the first clear statement of a regular alternation of
generations in thallophytes is by Sacus (42), who endeavored to
bring together the facts known in algae and fungi, and to compare
them with alternation in the Archegoniatae. Sacus states that
the life cycle of algae and fungi is similar to that of the Arche-
goniatae, one generation producing sexual organs, and the other
forming spores. PrincsHem (36) held quite a different view,
namely that the alternation of generations in the thallophytes
consists in the regular succession of a non-sexual or “neutral”
generation with a sexual generation, both generations being of
similar structure.
Both these views, one by Sacus, who recognized two distinct
generations in thallophytes, and the other by PrincsHEIM, who
regarded the two alternating generations as similar structures,
have continued to find followers. . VINES (65) held the view that
most of the thallophytes have no alternation of generations,
since both sexual and asexual modes of propagation are directly
dependent upon the external conditions, and that an alternation
of generations in algae comparable to that in the bryophytes is
only found in Coleochaete and Chara. CELAKOVSKY (5), although
opposing PRINGSHEIM in his conception of alternation of genera-
tions in the Archegoniatae, which he designated as the “‘antithetic,”
agreed with him in his conception of alternation in thallophytes,
in which the successive generations are alike and which conception
he designated as the “homologous.” PRINGSHEIM’S conception of
the homologous alternation of generations in the Archegoniatae
has received its principal support in LaNc’s experimental cultures
(26) of the apogamous development of the sporophytes on pro-
thallia of several pteridophytes. CELAKOvsKy’s conception of
alternation of generations in the Archegoniatae was taken up fifteen
years later by Bower (4), who has supported this conception by
his theory of an interpolated sporophytic generation. BOWER
holds that the antithetic alternation originated by the intercalation
of a non-sexual generation as a new development between two
gametophytic generations. This interpolation of a special sporo-
phyte probably took place, according to Bower, in the algae-like
ancestors of the Aphesonsatae as they emerged from an aquatic
484 BOTANICAL GAZETTE [DECEMBER
life to a land life. Moreover, some of the thallophytes, such as
Coleochaete, Ascomycetes, and Florideae, he holds show the begin-
ning of an antithetic alternation. STRASBURGER (54), summarizing
cytological results, advanced the theoretical conception of the
periodic reduction of chromosomes in the life cycle in plants, thus
establishing the view that the x and 2% generations which complete
the life cycle of the plant are quite distinct from each other. This
view has proved the antithetic character of the two generations
from a cytological standpoint.
Since that time, cytological investigations of algae which directly
touch the problem of the alternation of generations are those of
Kies (23), WittrAms (66), WoLFE (70), Lewis (27), SVEDELIUS
(60), and of the author (71, 73, 74, 76).
K.eExs conducted experimental cultures of several algae, such
as Vaucheria, Oedogonium, and others. By controlling factors such
as light, temperature, moisture, oxygen, and chemical composition
of nutritive media, he succeeded in producing any kind of reproduc-
tion, either sexual or asexual; in other words, he observed no regular
alternation of neutral and sexual generations.
WILLIAMs discovered a reduction of chromosomes during the
tetraspore formation in Dictyota, and this led him to conclude that
the tetrasporic plant of Dictyota is a sporophytic generation derived
from the fertilized egg.
WoLrFE showed for Nemalion that the cells of the cystocarp
have double the number of chromosomes found in the sexual plant,
thus presenting the first cytological evidence that the cystocarp of
the red algae is sporophytic in character. He placed the period of
chromosome reduction at the time of carpospore formation, basing
his conclusion on a count of chromosomes in the mitosis just
previous to the formation of the carpospores. However, he did not
describe the phenomena characteristic of chromosome reduction,
namely, the period of synapsis followed by the two divisions which
distribute the chromosomes so as to give a numerical reduction.
After the publication of Wit1aMs’ and Wo tre’s work, STRAS-
BURGER expressed his agreement with WiLLrIAms’ conclusion con-
cerning the alternation of generations in the brown algae, but
remarked that the tetraspores of the red algae seemed to be different
1912] . YAMANOUCHI—CUTLERIA 485
from those of the Dictyotaceae, and that the place of the chromo-
some reduction in the red algae should be sought elsewhere than
at the formation of tetraspores because some of the red algae
develop no tetraspores, but monospores instead. But immediately
after the appearance of this view of STRASBURGER, the author’s
work on Polysiphonia was published. He found that the reduction
of chromosomes, instead of taking place at the formation of carpo-
spores as reported by WoLrFE, occurred at the development of the
tetraspores. Thus in the life cycle of Polysiphonia, the sporophytic
generation is not only represented by cystocarpic branches, but
also extends to the tetrasporic plant that alternates antithetically
with the sexual plant.
Lewis then worked out the cytology of Griffithsia, special atten-
tion being paid to the problem of the alternation of generations.
The place of the reduction of chromosomes is in tetraspore
formation as in Polysiphonia. He concludes that there is in
Griffithsia as in Polysiphonia an antithetic alternation of genera-
tions, the gametophytes being represented by the sexual plants and
the sporophytes by the sporogenous cells of the cystocarps. In
addition to this, there is a regular succession of tetrasporic indi-
viduals and sexual individuals; tetrasporic individuals resemble
the gametophytes in morphological differentiation and the sporo-
phytes in number of chromosomes. He regards the tetrasporic
and sexual plants as presenting homologous alternation.
SVEDELIUS studied the alternation of generations in Delesseria.
Although his work does not cover the whole life cycle of this type,
the cytological studies being made only in the development of
tetraspores and vegetative mitosis in both tetrasporic and female
plants, yet by comparing his work with that on Nemalion, Poly-
siphonia, and Griffithsia, he has come to the conclusion that there
is an alternation of generations in Delesseria as in Polysiphonia.
The existence of an alternation of generations in the thallo-
phytes, though somewhat obscure in the green algae on account
of insufficient investigations, has been clearly proved by the cyto-
logical studies on Fucus and Dictyota among the brown algae, and
on Nemalion, Polysiphonia, Griffithsia, and Delesseria among the
red algae. Let us now turn to the situation in Cudleria.
486 BOTANICAL GAZETTE ; [DECEMBER
Since FALKENBERG (12) first suggested that Cuwiéleria and
Aglaozonia may represent the two phases of the life cycle of a
single species (Cuéleria), many workers have tried to secure Agla-
ozonia plants from the cultures of fertilized gametes of Cutleria.
FALKENBERG and REINKE were the only two who succeeded in
producing the form Falkenbergiana, an Aglaozonia form. The
rest of the investigators succeeded in producing either the form
Falkenbergiana or the form Churchiana from unfertilized gametes.
Among later workers, SAUVAGEAU, by carrying on his cultures for
years, succeeded in getting Aglaozonia or Cutleria from unferti-
lized gametes of Cutleria adspersa. The conclusion drawn from
this result naturally was that the alternation of generations is not
necessary, but rather, as it might be called, facultative. OLTMANNS
and STRASBURGER have agreed with this view of SAUVAGEAU.
The so-called polymorphic character of Culleria, however, needs
analytical consideration. The results of the author’s investigation
are as follows:
The investigation of Cudleria plants bearing gametangia showed
that the nucleus has 24 chromosomes in both the vegetative and
germ cells. The number is doubled at fertilization by the union
of the sexual nuclei. The Culeria plant is therefore a gametophyte
whose chromosome number is 24. As all now agree, the fertilized
gamete or egg with its fusion nucleus should represent the 2%-
generation, and so the fertilized gamete of Cutleria is the beginning
of the 2x-generation. The studies of the germination of the
fertilized gamete have shown that the 2x condition continues in
further development. The sporeling developed into a structure
unlike the young filamentous form of the parent Cudleria as found
in nature, but composed of a small upright column and a propor-
tionally large basal disk expansion which became later the dominat-
ing region of the further development. Later this expansion
develops the zonal structure of Aglaozonia as found in nature, and
not only resembles A glaozonia in outer morphology, but also in the
nuclear conditions, the expansion in cultures and Aglaozonia in
nature both having 48 chromosomes. Aglaozonia in nature pro-
duces zoospores, during whose formation 48 chromosomes are
reduced to 24, and the zoospores contain 24 chromosomes. The
1912] YAMANOUCHI—CUTLERIA 487
zoospore with the haploid number germinates with no fusion. The
product of the zoosporeling is a filamentous individual like young
Cutleria, and never produces the zonal flattened form of the parent
Aglaozonia.
The condition in cultures is very different from the environment
in nature. In nature the gametes and zoospores are set free at a
depth of 1~5 meters and in cultures they are discharged and kept
in sea-water at a depth less than 1 5-20cm. Besides, the intensity
of light, water-pressure, temperature, and motion of water are also
different in these two different environments, and yet the sporelings
of the fertilized gametes developed into the flattened disk like
young Aglaozonia and those of the zoospores grow into filamentous
plants like young Cwudleria. That the potentialities of those two
kinds of sporelings in forming invariably the particular individuals
different from the parent forms as in nature, even under environ-
mental conditions so different from what is found in nature, and that
the potentialities of the two different sporelings have given rise to
the particular different individuals, even when they were kept in
Similar cultures, show that the potential characters of their germ
plasm has dominated over the influence of environmental con-
ditions; this dominancy of the innate character over the environ-
mental influence is fundamentally different from the experiments
of Kress on certain green algae (23). Although the two kinds of
sporelings from fertilized gametes and zoospores in the cultures
have not been kept growing to the stage of reproduction, yet it
Seems safe enough to infer that the disklike expansion developed
from the sporelings of the fertilized gamete will be identical with
Aglaozonia as found in nature, and the filamentous structures of
the zoosporelings will be Cudleria. Thus Cutleria plants with
zoospores represent a gametophytic generation, and A glaozonia
plants with fertilized gametes the sporophytic generation. These
two generations alternate in the life history of Cuéleria. The two
generations, from the above observations of the cell organization,
are fundamentally different and could not be regarded as an example
of polymorphism in the sense of OLTMANNS (35).
The observations on the sporelings of the unfertilized gametes
and studies of their cell organization undoubtedly show that the
<n *
488 BOTANICAL GAZETTE [DECEMBER
female gametes of Cutleria are capable of developing into the flat-
tened disk like Aglaozonia in nature. Though at first their external
morphology presents irregular deviations from forms in nature,
the nuclear divisions are perfectly normal. The culture of the
sporelings was not continued up to production of reproductive
organs, and consequently the discussion cannot be carried on any
further. This apogamy may indeed be a reversion to the ancestral
type of asexual spores which certainly existed before the appear-
ance of sexuality in the gametophytic generation, but when
sexuality is once established, the fusion of gametes and thereby the
sporophytic generation is interpolated as a secondary structure
in which the reduction of chromosomes occurs.
Summary
The nuclear conditions in the life history of Cufleria multifida
may be summarized as follows: -
1. The nucleus of both male and female plants contains 24
chromosomes, and the male and female gametes contain the same
number.
2. In the union of gametes the number is doubled, and 48
chromosomes appear in the sporelings, which develop into the
Aglaozonia form of Cutleria. Therefore, the individual bearing the
name of Cuileria multifida represents the gametophytic phase of
the species, 24 being the gametophytic number of chromosomes;
and the Aglaozonia form of Culleria represents the sporophytic
phase, 48 being the sporophytic number.
3. Aglaozonia reptans contains 48 chromosomes, and the number
is reduced in zoospore formation, the zoospore containing 24
chromosomes. The zoospore with the reduced number of chromo-
somes germinates without conjugation. The individual grown
from the germinating zoospore presents a striking similarity to the
young form of Cuilleria in nature and contains 24 chromosomes,
the same number as the latter. Therefore it is evident that the
individual bearing the name of A glaozonia reptans represents the
sporophytic phase of the species, 48 being the sporophytic number
of chromosomes, and that the gametophytic phase is represented
1912] YAMANOUCHI—CUTLERIA 489
by the individual grown from the zoospore and resembling the
young form of Cuéleria in nature. It is certain that Aglaozonia
repians as it occurs in nature is identical with the Aglaozonia form
of Cutleria multifida as developed in cultures and now determined
to be the sporophytic phase of the species.
4. Therefore, Cutleria multifida and Aglaozonia reptans repre-
sent respectively gametophytic and sporophytic generations of a
single species, the two generations alternating in the life history of
Cutleria.
5. The female gamete of Cudleria may germinate apogamously.
There is no irregularity in the mitotic process, 24 chromosomes
being invariably present. The individual produced, in its early
development differs somewhat from the product of the fertilized
gamete, but the fate of the apogamous individual was not deter-
mined.
University oF CrIcaco
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16. GrécorE, V., Les cinéses polliniques chez les Liliacées.. La Cellule 16: 235-
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, Les cinéses de maturation dans les deux régnes. L’unité essen-
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18. Harper, R. A., Sexual reproduction and the organization of the nucleus
in certain mildews. Carnegie Inst. Washington, Pub. no. 37. PP- 9?
pls. I-7. 1905.
19. HENNEGUY, L. F., Lecons sur la cellule. Paris. 1896.
20. Hormeister, W., Vergleichende Untersuchungen der Keimung, Entfaltung,
und Fruchtbildung hdherer Kryptogamen und der Samenbildung der
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21. JANCzEwsxI, Ep. pg, Note sur la fécondation du Culleria adspersa et les
affinités des Cutlériées. Ann. Sci. Nat. Bot. VI. 16: 210-226. pls. 13, 14-
14.
17-
- Karsten, G., Die Entwicklung der Zygoten von Spirogyra jugalis Ktzg.
S vom ay Ett. pl. ft. 190
23. Kreps, G., Ueber den Cansenthonseecline der Thallophyten. Biol.
Centralbl. 19: 209-226. 1899.
24. Kuckuck, P., Bemerkungen zur marinen Algenvegetation von Helgoland.
Wisstvischaftliche Meeresuntersuchungen, herausgegeben von der Kom-
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tionswechsel von Cuéleria multifida Grev. Wiss. Meeresunters. Neue
Folge 3:110~-113. 1899.
26. Lane, W. H., On apogamy and the development of sporangia upon fern
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1898.
1912] VYAMANOUCHI—CUTLERIA 491
27. Lewis, I. F., The life history of Griffithsia Bornetiana. Ann. Botany
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1888.
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280
46,
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‘
: Chervanions sur quelques Dictyotacées et sur un Aglaozonia
492 BOTANICAL GAZETTE [DECEMBER
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55+
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1912] YAMANOUCHI—CUTLERIA 493
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note). Bot. Magazine Tokyo 25:10-12. r1o1I.
“
EXPLANATION OF PLATES XXVI-XXXV
figures were drawn with the aid of a camera lucida under the Zeiss
apochromatic objective 1.5 mm. N.A. 130, in combination with compensating
ocular 12; except figs. 200-202, which were drawn with compensating ocular
18; figs. 8,9, 14, drawn with compensating ocular 8; and figs. 1-7, 12, 13, 16, 17,
53, 144-150, drawn with ocular 4; and figs. 10, 11, 15, which were drawn under
Zeiss apochromatic objective 16 mm. combined with compensating ocular 12.
The figures are reduced to one-half the original size. Figs. 1-15 are-in the text.
PLATE XXVI
The formation of the male gametangium of Cutleria multifida
Fic. 16.—Portion of the thallus of a male plant, showing a single layer of
superficial cells and the larger cells below
Fic. 17.—Portion of the thallus of a we plant, where 4 superficial cells
have grown into papillae, the male gametangium initials.
Fic. 20.—Metaphase: the nuclear cavity in this stage strikingly diminished.
Fic. 21.—A filament with two male gametangia: nucleus in the young
gametangium initial at metaphase.
rls 22.—Anaphase that follows the metaphase of fig. 2
Fic. 23.—Nucleus already sto! bes each tase ick nucleus now in
Sita = chromosomes present in
Fic. 24.—Nucleus in the lower cell i in pre prophase, while the nucleus
in the se! cell is still in early prophase.
404 BOTANICAL GAZETTE [DECEMBER
Fic. 25.—Similar stage to fig. 24, excepting the presence of centrosome-
like eee at the poles.
Fr .—Nucleus in the lower cell in anaphase; nucleus in the upper cell
in ees condition.
Fic. 27. Dae ag of the nucleus in the upper cell of 2-celled stage; the
lower oy is not dra
Fic. 28.—Late He of the nucleus in the upper cell; nucleus in the
lower nae in resting condition
IG. 29.—Telophase of nicleds of the upper cell; a new cell wall is being
laid down between two daughter nuclei.
Fic. 30.—Male gametangium of 3 cells: the nuclei in the upper two cells
are in resting condition; the nucleus in the basal cell in prophase, showing
24 chromosomes and a nucleolus.
1G. 31.—Male gametangium of 3 cells: the nucleus in the terminal cell
is in metaphase; centrosome-like structures at the poles of the spindle.
Fic. 32.—Male gametangium of 3 cells: the nucleus in the terminal cell in
metaphase, with centrosome-like structures at the poles; the nucleus in the
middle cell in anaphase, and that of the basal cell in resting stage.
Fic. 33.—Male gametangium of 4 cells: the nucleus in the terminal cell is
in metaphase; that of the middle cell in prophase, showing 24 chromosomes.
1G. 34.—Male gametangium of 4 cells: two nuclei are in prophase; 24
chromosomes are clearly present; one in anaphase and the other in resting
condition.
Fics. 35, 36.—Mitotic figures of the nucleus in a vegetative filament:
fig. 35, anaphase; fig. 36, prophase, showing 24 chromosomes.
Fics. 37, 38.—Cross-section of a male gametangium of 5 cells: fig. 37,
metaphase of the mitosis which divides the filament into two rows of cells;
fig. 38, prophase of the same, showing 24 chromosomes.
Fic. 39.—Tip of a vegetative filament, showing stages in the formation of
male gametangia; the male gametangia have arisen from the third, fourth,
sixth, and seventh cells; four nuclei in the three young gametangia are in
prophase; 24 chromosomes can be counted in each.
1G. 40.—Portion of a male gametangium of 2 rows of cells: one nucleus in
metaphase, one in prophase showing 24 chromosomes, and three others in
the (si condition.
. 41.—Portion of a more advanced male gametangium: four nuclei
in Sophie clearly ee the 24 chromosomes.
G. 42. ross-section of a male gametangium at about = same stage
as in fig. 41; one nucleus is in prophase; 24 chromosomes prese
Fic. 43.—Portion of a male gametangium at about the same eres as in
fig. 41; two nuclei are in anaphase.
Fic. 44.—Cross-section of a male gametangium at about the same stage
as in fig. 43: two nuclei in prophase of the mitosis which divides the filament
into a structure with four rows of cells.
1912] YAMANOUCHI—CUTLERIA 495
Fic. 45.—Portion of a male gametangium consisting of 4 rows of cells:
one nucleus is in anaphase.
Fic. 46.—Portion of a male gametangium at about the same stage as in
fig. 45: one nucleus is in prophase, showing clearly 24 chromosomes.
Fics. 47, 48.—Portion of a male gametangium at a more advanced stage:
one nucleus in fig. 47 in prophase, showing 24 chromosomes; one nucleus both
in tt 47 and 48 in metaphase; and two nuclei in fig. 48 in anaphase.
IG. 49.—Portion of a male gametangium, showing the last division of
nuclei; = nucleus is in prophase and the other in metaphase.
IG. 50.—Cross-section of a male gametangium at about the same stage
in fig. 49; one nucleus is in prophase, two others in metaphase of the mitosis
which hae the filament into a structure of 8 rows of cells.
G. 51.—Cross-section of a mature male gametangium: nuclei are in rest-
ing con
2.—Cross-section of a mature male gametangium, showing the
sdgts des are associated with the red pigment.
PLATE XXVII
The formation of the female gametangium of Cutleria multifida
Fic. 53.—Portion of thallus of a female plant, showing a single layer of
superficial cells and the larger cells below; one of the superficial cells has in-
creased in size, and will be the female gametangium later.
1G. 54.—One of the superficial cells becomes still larger in size: nucleus
is in prophase; 24 chromosomes and a nucleolus are present
1G. 55.—Nucleus in metaphase; centrosome-like structures at the poles
of spindle.
Fic. 56.—Anaphase
Fic. 57.—Later telophade: cell wall is being laid down between the newly
formed oe nuclei.
_ Fic. 58.—Female gametangium of 2 cells.
Fic. 59.—Nucleus of the upper cell in prophase; nucleus of the basal cell
in resting condition
Fic. 60. tens of upper cell in Egos ae
Fic. 61.—Nucleus of upper cell in anaphase.
Fic. 62.—Late telophase of nucleus in upper cell.
Fic. 63.—Female gametangium consisting of 2 cells: nucleus of basal
cell in metaphase.
Fic. 64.—Nucleus in basal cell in anaphase.
Fic. 65.—Female gametangium of 3 cells: nucleus of basal cell in prophase;
24 chromosomes and a nucleolus are present.
Fic. 66.—Nucleus of terminal cell in prophase, showing 24 chromosomes;
nucleus of basal cell in metaphase.
Fic. 67,—Nucleus of terminal cell in etguhane.
Fic. 68.—Nucleus of terminal cell in anaphase.
496 BOTANICAL GAZETTE [DECEMBER
Fic. 69.—Nucleus of middle cell in prophase.
Fic. 70.—Nucleus of middle cell in early anaphase.
Fic. 71.—Cross-section of a female gametangium of 2 cells: nucleus in
anaphase viewed from the pole, clearly showing 24 chromosomes.
Fic. 72.—Cross-section of a female gametangium of 5 cells: nucleus in
metaphase of the mitosis which divides the gametangium into a structure
composed of 2 rows of cells.
PLATE XXVIII
The formation of the female gametangium of Cuileria multifida (continued)
Fic. 73.—Cross-section of a female gametangium of 8 cells in two rows:
one nucleus in late prophase, showing 24 chromosomes.
1G. 74.—Portion of a female gametangium of 8 cells in two rows: one
nucleus in late prophase, polar view of which is shown in the previous figure;
nucleus in basal cell in early prophase.
Fic. 75.—Portion of a female gametangium of 7 cells: one nucleus is in
late prophase, showing 24 chromosomes, which will result in two cells arranged
side by side in the direction perpendicular to the plane of the paper.
Fic. 76.—Portion of a female gametangium of 8 cells: one nucleus in
anaphase.
Fic. 77.—Portion of a female gametangium of 8 cells: one nucleus in late
anaphase.
Fic. 78.—Cross-section of a female gametangium of 10 cells: one nucleus
in metaphase of the division which divides the gametangium into a structure
of three rows of cells.
Fic. 79.—Portion of a female gametangium of 10 cells: one nucleus in
metaphase.
Fics. 80, 81.—Portion of a female gametangium of tro cells: one nucleus
in anaphase in both figures.
Fic. 82.—Portion of a female gametangium of 10 cells: one nucleus is in
metaphase and two others have already divide :
Fic. 83.—Portion of a female ecnctateioin of 10 cells: one nucleus in —
prophase, showing 24 chromosomes, one nucleus in late anaphase and the other
two have already divided.
Fic. 84.—Portion of a female gametangium of 10 cells: one nucleus in
early metaphase viewed from the pole, showing 24 chromosomes.
Fic. 85.—Portion of a female gametangium of 12 cells: one nucleus in
anaphase and the other two have already divided.
Fic. 86.—Portion of a female gametangium of 12 cells: one nucleus in
early metaphase, viewed from the pole, showing 24 chromosomes; the other
nucleus in metaphase in lateral view.
Fic. 87.—Portion of a female gametangium of 15 cells: one nucleus in
prophase.
Fic. 87a.—The nucleus in prophase in the previous figure under higher
magnification: 24 chromosomes present.
1912] : YAMANOUCHI—CUTLERIA 497
Fics. 88, 88a.—Portion of a female gametangium of 18 cells: one nucleus
in anaphase, which is shown under higher magnification in fig.
Fic. 89.—Cross-section of mature female gametangium in 4 tiers.
Fic. 90.—Cross-section of mature female gametangium in 8 tiers.
FiG. 91.—Two cells of a mature female gametangium: the plastids and
dense cytoplasm are thick along the inner wall; nuclei in resting condition.
Fic. 92.—One cell of a mature female ee plastids and cyto-
plasm are thick toward the outer wall; nucleus in resting condition.
Fic. 93.—A female gametangium entirely gece after the escape of
female gametes.
PLATE XX1X
The union of gametes and germination of the fertilized female gamete
Fic. 94.—Two male gametes which have stopped the swimming movement;
cilia are withdrawn, nuclear membranes are scarcely visible, and the reticulum
shows 24 chromosomes.
IG. 95.—Union of male and female gametes: nucleus of the male gamete
shows 24 chromosomes and that of the female sora is in the resting condition;
no cell membrane is recognizable around the gamet
Fic. 96.—Cytoplasm of male gamete is satiny re with that of female
gamete and the whole body of the united gametes has about assumed the
spherical form; cell membrane has appeared; male nucleus still shows 24
chromosomes.
Fic. 97.—Male nucleus has advanced toward the female nucleus.
Fic. 98.—Male nucleus has moved nearer toward the female nucleus.
Fic. 99.—Male nucleus is attached to the female nucleus
Fic. too.—Male nucleus, showing 24 chromosomes, and female nucleus in
resting ee
Fic. tor.—Male nucleus very closely applied to the female nucleus; 24
irouleatinia of the male nucleus still recognizable; a part of the cell wall of
the sporeling has thickened.
IG. 102.—-Part of the male nucleus, evidently consisting exclusively of
chromosomes, has become submerged in the female nucleus, which is in the
resting moreso
IG. 103.—Male nucleus has completely entered into the female nucleus:
dense shitenie granules are to be seen at the part of female nucleus where
the male nucleus has entered.
Fic. 104.—Fusion nucleus: network contains a number of chromatin
granules that show no distinction between those derived from the male and
female nuclei.
1G. 105.—Fusion nucleus is in the resting condition.
Fic. 106.—Prophase: 48 chromosomes and a nucleolus are present; the
chromosomes are apparently alike both in form and size; the sporeling shows
an elongation at a point where the cell wall is thickened.
498 BOTANICAL GAZETTE [DECEMBER
Fic. 107.—Metaphase: thickening of cell wall is present, though the
sgn of the sporeling has not yet begun.
Fic. 108.—Fusion nucleus in very early prophase: characteristic elonga-
tion of the sealing and thickening of the corresponding cell wall at that part
is remarkable.
Fic. 109 —Portion of the elongated part of a sporeling with a resting
nucleus.
Fic. 110.—Cross-section of the elongated portion of a sporeling at the
same stage as the previous figure; fusion nucleus in prophase; 48 chromosomes
are present.
Fic. 111, a, .—T wo sections of a sporeling: nucleus in prophase, showing
48 chromosomes; elongation and correponding thickening of the cell wall are
evident.
Fic. 112. a Motigiose: Elongation of the sporeling and thickening of the
cell wall at the point of the elongation are marked; axis of the figure is in the
direction of the elongation.
Fic. 113.—Cross-section of a sporeling perpendicular to the axis of elonga-
tion; nucleus in late metaphase.
1G. 114.—Cross-section of a sporeling at about same stage as in fig. 112;
nucleus in metaphase is seen from the pole; 48 chromosomes are present.
IG. 115.—Sporeling in 2-celled stage: two nuclei in resting condition.
Fic. 116.—Sporeling in 2-celled stage: nucleus in terminal cell in prophase,
and that of basal cell in resting condition.
Fic. 117.—Sporeling in 2-celled stage: nucleus in terminal cell very small
and in resting condition, while that of basal cell shows very early prophase.
1G. 118.—Cross-section through a basal cell of a sporeling in 2-celled
stage: nucleus is in late prophase; 48 chromosomes present.
Fic. r19.—Sporeling in 2-celled stage: nucleus in terminal cell in early
prophase, and that of basal cell in resting condition.
Fic. 120.—Sporeling in 2-celled stage: nucleus in terminal cell in prophase,
showing 48 chromosomes.
Fic. 121.—Sporeling in 3-celled stage: nucleus in basal cell in prophase,
showing 48 chromosomes.
Fic. 122.—Sporeling in 3-celled stage: nucleus in basal cell in metaphase,
Fic. 123.—Sporeling in 3-celled stage: all the nuclei in prophase, showing
48 chromosomes.
PLATE XXX
The germination of the unfertilized female gamete
Fic. 124.—A female gamete in the resting condition: cell wall does not
seem to be developed excepting at the point where a slight elongation is
noticeable.
Fic. 125.—Cell wall is now recognizable, especially at the elongated point;
nucleus in resting condition.
1G. 126.—Nucleus with 24 chromosomes is prophase.
1912] YAMANOUCHI—CUTLERIA 499
Fic. 127.—Nucleus in metaphase: contour of sporeling sion spherical.
“ase
Fic
istic aoigatich and the thickened cell wall of the elongated part are recog-
izable.
Fic. 130.—Metaphase of same stage as in previous figure: axis of the
figure is perpendicular to that of the previous one.
Fic. 131.—Anaphase
Fic. 132. Metaphase of the similar stage as in figure 130, but axis of the
figure is perpendicular to that.
Fic. 133.—Anaphase
Fic. 134.—Late elophase® Dapecikeae of the sporeling is remarkable.
— 135.—Sporeling of 2-ce stage: nuclei in resting condition.
136.—Sporeling of Ser stage: nucleus of terminal cell in prophase;
24 crmosoine present.
137-—Sporeling of 2-celled stage: nucleus of terminal cell in meta-
pale eee from pole; nucleus of basal cell in prophase; 24 chromosomes
present.
IG. 138.—Sporeling of 2-celled stage: nucleus of terminal cell in prophase;
form of tg chromosomes is rather long.
Fic. 139.—Sporeling of 2-celled stage: nucleus in basal cell in anaphase
Fic. 140.—Sporeling of 2-celled stage: nucleus in terminal cell in late telo-
phase and that of basal cell in metaphase, showing 24 chromosomes in polar
view.
141.—Sporeling in 3-celled stage: nucleus of basal cell in prophase,
shaving “ chromosomes.
Fic. 142 welsh in 3-celled stage: nucleus of middle call in prophase,
sticigte’ 24 chromosom
Fic. 143. = Stoning: in 3-celled gue nucleus of basal cell in metaphase.
Fic. 144.—Sporeling of 12-celled stag
Fic. 145.—Sporeling of 13-celled pace
Fic. 146.—Sporeling of 22-celled stage.
PLATE XXXI
The formation of the zoosporangium of Aglaozonia reptans
Fic. 147.—Portion of a young thallus, showing a single layer of super-
ficial éells and the larger cells below.
Fic. 148.—Portion of a young thallus, showing a single layer of superficial
cells, hypodentist cells, and the larger cells below
Fic. 149.—Portion of thallus in more advanveed stage.
Fic. 150.—Portion of thallus in still more advanced stage: superficial cells
have grown in size and will be zoosporangia or zoospore mother cells.
Fic. 151.—Young zoospore mother cell and stalk c
Fic. 152.—Zoospore mother cell of characteristic dab-abayes nucleus in
resting condition.
500 BOTANICAL GAZETTE [DECEMBER
Fic. 153.—Resting nucleus slightly increased in size.
Fic. 154.—Resting nucleus with radiations at one pole
Fic. 15 5.—Section of a mother cell cut obliquely: resting nucleus with
radiations at two poles.
1G. 156.—Nucleus in very early prophase, situated at one side, with a
centrosome-like structure but no radiations.
Fic. 157.—Nucleus situated at the ne part of the mother cell with
two centrosome-like structures and radiation
IG. 158.—Nucleus situated at the upper Part with a centrosome-like
structure and radiations.
Fic. I wt Wace situated at the middle part with no radiations.
PLATE XXXII
The formation of the zoosporangium of Aglaozonia reptans (continued)
Fic. 160.—Nucleus of a zoospore mother cell in prophase, chromatin
network irregularly traversing the nuclear cavity.
Fics. 161-168.—Nucleus in synapsis.
Fic. 161.—Chromatin threads have begun to be arranged in form of loops
which become attached by their ends to a part of the nuclear membrane.
1G. 162.—Formation of loops is further advanced
Fic, 163.—Cross-section of a mother cell; attachment of loops is at the
side.
_ Fic. 164.—Attachment of loops to the nuclear membrane is all the way
around
Fic. 165.—Some of the loops are quite shortened and thickened, and yet
some others are left behind and can be recognized running across the cavity.
Fic. 166.—Section near the base of crowded loops in contact with the
membrane, showing 48 or more isolated cut sections of the loops.
Fic. 167.—Loops have shortened and thickened.
Fic. 168.—Nucleus emerging from synapsis: two pairs of chromatin
loops are already in the form of chromosomes.
Fic. 169.—Majority of the two arms of each of these loops are going to
form paired arms of bivalent chromosomes.
Fic. 170.—Diakinesis stage: 24 bivalent chromosomes are present; no
polar radiations.
Fic. 171.—Spindle with two poles has just formed.
Fic. 172.—Metaphase
Fic. 173.—Polar view of the metaphase, showing 24 bivalent chromosomes
at the equatorial plate.
PLATE XXXIII
The formation of the zoosporangium of Aglaozonia reptans (continued)
As the stage advances, gradual increase of the thickening of the cell wall
at the tip of the mother cell is noticeable.
Fic. 174.—Late metaphase.
Fic. 175.—Anaphase: 24 chromosomes at each pole.
1912] VYAMANOUCHI—CUTLERIA 501
Fic. 176.—Anaphase, side view
Fic. 177.—Anaphase, further advanced.
Fic. 178.—Telophase.
Fic. 179.—Later telophase: two daughter nuclei in resting condition.
Ic. 180.—Two daughter nuclei increased in size: each nucleus has
a st the poles.
Fic, 181.—Upper nucleus has grown considerably larger than the lower
one.
Fic. 182.—Two nuclei are in contact.
Fic. 183.—Upper nucleus is in prophase; lower one still in resting condi-
tion.
Fic. 184.—Two nuclei simultaneously in metaphase.
Fic. 185.—Anapha
Fic. 186.—Late anaiihase: a group of chromosomes at one pole of the
upper nucleus is not indicated in this figure.
PLATE XXXIV
The formation of the zoosporangium of Aglaozonia reptans (continued)
Fic. 187.—Telophase of the second division in the mother cell.
Fic. 188.—Late telophase.
Fic. 189.—Metaphase of the third division.
Fic. 190.—Telophase of the same: 8 nuclei present.
Fics. 191~193.—Zoospore mother cells drawn from unstained preparations.
_ Fic. 191.—Nucleus in prophase: numero eS > various sizes are
Hea, ogi! globular structures of larger size are plast
IG. 192.—Four-nucleate stage: numerous granules om visible; plastids
have ace in number.
193.—Eight-nucleate stage: plastids have much increased in number
and the thicknbes of the cell wall at the top of the mother cell is noticeable.
194.—Cross-section of a mother cell at about same stage as in fig. 190;
ie mostly arranged near the cel] membrane
195.—Portion of a mother cell near iustuals thickness of the cell
' wall at the top of the mother cell has increased; plastids moving toward the
nuclei and surrounding them
IG. = —Later stage: piatids are around the nuclei.
197.—Portion of a mother cell: cytoplasm has become detached
from nee cell wall and cleavage furrows have appeared, so that general outlines
of individual zoospores are established.
Fics. 198, 199.—Portion of a mother cell containing zoospore
oo.—Portion of cell wall at the tip of a mother cell meee maturity:
the cell wall i in this part is considerably thickened and swollen.
Fic. 201.—Later stage: the cell wall at the tip of the mother cell has
disintegrated into two lamellae.
Fic. 202.—Further advanced sta. hing the discharge of zoospores:
disintegration has still progressed ae ees 2 the cell wall into three lamellae.
502 BOTANICAL GAZETTE [DECEMBER
PLATE XXXV
The germination of the zoospore of Aglaozonia reptans
IG. 203.—Zoospore 2 hours after becoming quiescent: cell wall has just
developed; — nucleus with a centrosome-like structure and radiations.
FIG. 20 oospore 20 hours after becoming quiescent: nuclear condition
is cut aienslar to fig. 203.
Fic. 205.—Zoospore 24 hours after becoming quiescent: no radiations
visible.
Fics. 206-208.—Drawn from material fixed 24 hours after becoming
quiescent. _
Fic. 206.—Resting nucleus with radiations: elongation of the’ sporeling
and thickening of cell wall at the elongated part is noticeable.
Fic. 207.—About the same stage as in the previous figure.
Fic. 208.—Early prophase
Fic. 209.—Prophase: 24 chromoeunes clearly present.
Fic. 210.—Cross-section through the elongated part of a sporeling: nucleus
in prophase, showing 24 chromosomes and a nucleolus.
Fic. 211.—Metaphase: general contour of the sporeling is spherical.
Fic. 212.—Polar view of the metaphase; 24 chromosomes clearly in view.
Fic. 213.—Metaphase: the sporeling has elongated.
Fic. 2 214 _—Metaphase viewed from the pole: the sporeling has elongated
ts.
Fic. 217.—Sporeling of 2 cells: nucleus of the basal cell is in prophase;
24 chromosomes visible.
Fic. 218.—Sporeling of 2 cells: nucleus in metaphase.
Fic. 219.—Sporeling of 2 cells: nucleus of terminal cell in early prophase;
24 chromosomes present.
Fic. 220.—Nucleus of terminal cell in prophase.
Fic. 221.—Nucleus of terminal cell in metaphase viewed from pole.
Fic. 222.—Two nuclei simultaneously in prophase; 24 chromosomes
Fis. rhs —Sporeling of 3 cells.
24.—Sporeling of 3 cells: nucleus in middle cell in prophase; 24
diccouacua present.
IG. 225.—Sporeling of 3 cells: nucleus in basal cell in prophase; 24 chromo-
somes present.
Fic. 226.—Sporeling of 4 cells.
Fic. 227.—Sporeling of 4 cells: nuclei in lower cells in metaphase.
Fic. 228.—Sporeling of 4 cells: two upper cells lie side by side in the direc- ;
tion perpendicular to the axis of the sporeling.
BOTANICAL ‘GAZETTE, LIV
PLATE XXVI1
YAMANOUCHI on CUTLERIA
ee Rey ee AO gE 7
fs ba a
PLATE XXVU
YAMANOUCHI on CUTLERIA
PLATE XXVIII
YAMANOUCHI on CUTLERIA —
YAMANOUCHI on CUTLERIA oe
YAMANOUCHI on CUTLERIA
BOTANICAL GAZETTE, LiV i PLATE X2AX1
ee ae
5 possi
YAMANOUCHI on CUTLERIA
PLATE XXXII
YAMANOUCHI on CUTLERIA
PLATE XXXII
YAMANOUCHI on CUTLERIA
PLATE XXXIV
BOTANICAL GAZETTE, LIV
if
Fi \
laa \\
f
YAMANOUCHI on CUTLERIA
Peake ech ae. eee el TE ee ee eee tS eee Pee eed oP ee Pee Sa SS FPS ee te ee Sl eee
YAMANOUCHI on CUTLERIA |
THE NATURE OF THE ABSORPTION AND TOLERANCE
OF PLANTS IN BOGS:
ALFRED DACHNOWSKI
The consideration of measured physical habitat conditions,?
which is desired as a basis for distributional relationships of plant
associations, their succession and morphological distinction, and
particularly for a theory of physiologically arid habitats, has not
rendered clearer the nature of the absorption of plants in bogs and
peat deposits. Interest in the study of the absorption and the vary-
ing degree of tolerance and resistance of plants growing in Ohio
bogs has been coincident with the determination of the quantita-
tive nature of the habitat factors, but it has been only through an
appreciation of the subordinate value of the physical habitat factors
that attention could be given to the special diosmotic properties
of the plants and of the substances absorbed, together with the
changes which the penetrating substances produce upon the plants.
The changes which the substances undergo internally or externally
to the absorbing cell or organ are relationships of equal importance
in the problem of nutritive metabolism, but a discussion of them
cannot be attempted as yet.
The evidence as to the réle of physical and biotic habitat factors,
derived from study of bog vegetation in its relations to the sub-
stratum, temperature, and evaporation, from consideration of
the relation of bog vegetation to the chemical nature of peat soils,
need not be reviewed here in detail. ‘It pointed to something else
than merely the atmospheric influences as ecological conditions
for the development of bogs and for the selection and growth of
plants tenanting such areas.
* Contribution from the Botanical Laboratory, Ohio State University. No. 71.
Read before the Botanical Society of America at the Washington meeting, rort.
Dacunowskt, A., The vegetation of oe Island (Ohio) and its relations to
meee elec and evaporation. Bor. GAz. 52:1-33, 126-150. 19It.
———, The relation of Ohio bog vegetation to the chemical nature of peat soils’
Bull, Torr. Bot. Club 39:53-62. 1912.
503] [Botanical Gazette, vol. 54
504 BOTANICAL GAZETTE [DECEMBER
The evaporation in a bog forest averages 8.1 cc. daily and shows
a close correspondence to the record obtained by others for a beech-
maple forest. In a bog meadow the rate (10.9 cc. daily) is less
than that for the open campus of the State University (15.8 cc.
daily). As far as local atmospheric conditions are concerned, the
rate of evaporation is not a sufficient cause to determine succession
of vegetation, nor are the differences in the rates efficient limiting
factors.
The réle of substratum temperature is obviously not the most
direct factor in southern localities contributing to the causal rela-
tion between water requirements of bog plants and available supply.
Neither has the coefficient of the differences between soil and air
temperatures a greater value in the selection of plants for bog areas,
or in their root functions. :
The concentration of mineral salts in bog water from various
plant associations ranges between 40 and 160 parts per million;
the acidity of the solutions varies from less than 0.00075 to 0.004
normal acid, when titrated with NaOH. There seem to be no free
“humus” acids. The acid reaction noted can be attributed to
adsorption phenomena,; especially to the selective absorbent power
of the cell colloids of disintegrating plant tissue which retain, as
BAUMANN and GULLY’ have shown, chiefly the basic ions of dissolved
salts. ‘The osmotic pressure of the solutions in the various associa-
tions is very nearly alike in the several plant zones and about the
same as that of lake and river water. The differences cannot be
associated with factors limiting the distributional relationships
and the activity of plants in bogs.
Variations in the position of the water table do not influence
the character of the vegetation, nor do they offer an explanation of
the xerophytic structure of the plants, for the peat mat upon which
the more typical bog xerophytes and heath associations succeed
one another is mote often a floating mat and moves with any change
4 TRANSEAU, E. N., The relation of plant societies to evaporation. Bot. Gaz.
45:217-231. 1908.
Futter, G. S., Evaporation and plant i Bor. GAz. 52:193-208. I9II.
5 CAMERON, F. K., The soil solution. rorr. p. 55.
6 BauMANN, A., und Gutty, E., Uber die freien Humussiuren des Hochmoores.
Mitt. K. Bayr. Moorkulturanst. 1910. pp. 31-56.
1912] DACHNOWSKI—BOG PLANTS 505
in the water table of the lake. In such a mat differences in the rate
of the movement of water through peat soil do not exist, and hence
are out of the question in the problem of the supply and the rate
of removal of water by plants.
The chemical analyses of Ohio peat soils, the data of which
appear elsewhere,? show wide variations, but there is a certain
uniformity in the range. When a correlation between the chemical
character of peat and the respective bog vegetation unit is attempted
the well defined relations are these:
In poorly decomposed bog meadow peat the percentage of
volatile matter is high, the percentage of fixed carbon, nitrogen,
and ash is low; the reverse is true for the well decayed peat sup-
porting a bog forest and deciduous trees.
Peat soils from various plant associations in bogs contain the
essential mineral salts such as potash, phosphoric acid, and others,
in inconsiderable quantities—only a fraction of 1 per cent. The
salts, it seems, play only a minor réle for protoplasmic activities,
and in the growth and ripening of bog plants. Tolerance and
resistance of plants to bog habitat is not an osmotic relation; it
cannot be related to a greater resistance to water absorption pro-
duced by high external osmotic pressure, nor, it seems, to the
lack of some one salt in the mineral content of the soil or in the
plants. The ash content of the wood of bog trees is less than 0.5
per cent, with an occasional maximum of about 1.5 per cent.
The solubility of the coarsely fibrous peat from bog meadows
is less than that of peat in more advanced stages of decomposition
supporting genetically higher associations of plants. The quantity
of nitrites, nitrates, and ammonia is very small and yet amply
sufficient to support luxuriant growth. Practically all the sub-
stances in solution are transition products of proteins and carbo-
hydrates arising through the action of obligate microorganisms.
Bacteriological investigations have shown clearly the importance
of biological processes. As a source of food to the microorganisms
and in the nature of the organic compounds produced during the
partial digestion of the upper layer of the vegetable débris, the
substratum constitutes an efficient limiting and selective factor.
7 DacunowskI, A., The peat deposits of Ohio. Geol. Surv. Ohio, Bull. 16, ro12
(in press).
506 BOTANICAL GAZETTE [DECEMBER
Now that it has been possible to show the inadequacy of
various of the physical environmental relations of plants in bogs
to account for the failure of some of the agricultural plants to thrive
and for the survival of others; and since differences in light-intensity,
in special absorptive powers of roots for peaty substrata, in fungal
mycorhiza, and in morphological limitations in the absorption and
in the conduction of water do not enter into the problem with the
agricultural plants used for the test experiments, it seems timely to
consider in more detail the specific réle of the organic decomposition
products in the relation between the required quantity of available
water and the quantity absorbed by the plants.
That some sort of regulatory, reciprocal mechanism, acting
within certain limits, is of the utmost importance in these species
seems evident from the fact that while the presence of structural
modifications is generally regarded as reaction in favor of a bog
vegetation, the most noteworthy characteristic which enables
invading plants to resist the unfavorable conditions is a greater
elasticity of functions and perhaps some specific place function.
What is the mechanism connected with the failure of many agri-
cultural plants to thrive in peat soils and in solutions of bog
water? What critical features, either as products of habitat or
congenital variation, do the surviving plants possess to regulate or
control the absorption of injurious organic bodies, and what are
the pathological aspects which involve dwarfing, leaf-fall, and
general senescence in most invading species alien to the habitat ?
A knowledge of the limits of functional variation within a
known species and its several varieties should prove very essential
as to the réle and the range of the individual and genetic differences
in the plants themselves, and the ability of the plants to inhibit
the absorption of deleterious bodies, or to neutralize the injurious
action of the substratum.
In the present preliminary paper data are submitted which
were obtained from experiments in the laboratory with several
standard varieties of grain sorghums, alfalfa, and bean. The
seeds were obtained from the United States Department of Agri-
culture through the office of seed distribution. The seeds were
germinated in sterilized quartz sand and employed in a manner
1912] DACHNOWSKI—BOG PLANTS 507
described in earlier papers. The physiological tests were made in
bog water from the central (cranberry-sphagnum) station on
Cranberry Island at Buckeye Lake, Ohio. All experiments were
made in duplicate series. Paper-covered ‘‘Mason’’ jars were
used containing 500 cc. of untreated bog water. The following
selected series in tables I to III is especially suggestive and typical.
The tables show at a glance which of the varieties is the more
efficient in counteracting the effects of injurious organic compounds.
Not only the relative transpiration quantities but also the morpho-
logical effects as shown by the general appearance of roots and leaves
bear out the observation that the rate of entrance of water is as
high and higher than the transpiration rate: The evaporating
power of the air during several of the experiments was relatively
high.
Especially in bog water of greater toxicity than that of the
date in the above series, the plants were in strong contrast to each
other. The rate of growth varied considerably according to
the amount of transpiration and to the supply of available water.
The decreased permeability of the plasmatic membrane of the
root-hair cells favored their efficiency in selective absorption and in
growth. When the rate of transpiration decreased, the root tips and
the tops made but slight growth. The roots were discolored for
some distance from the tip, appeared gelatinous, and not only their
surface but the meristematic tissue seemed injured, inhibiting the
formation of new laterals. The leaves were short and unfolded
imperfectly. At the beginning of the experiment the roots of the
stronger plants were able to counterbalance the injurious action
to a slight extent; light brown insoluble bodies appeared deposited
upon the surface of the roots. In dilute solutions of hog water the
Toots remained white. Invariably, however, the toxicity was
lessened most in plants whose ability to counteract the harmful
effects was most pronounced. The plants functioned less readily,
and their rate of reaction diminished as the active mass of bac-
terial products increased.
A characteristic behavior became evident in the increase of green
weight of the plants in the dilute solutions, and in the observation
that this effect was far from being uniform in all the cultures. The
508 BOTANICAL GAZETTE [DECEMBER
deleterious action of bog water was, on the whole, less marked upon
the tops than upon the roots. Nevertheless the green weight of
some of the plants with a lower transpiration value was greater than
that of the plants transpiring more strongly. Examples are num-
bers 3, 5, and 7in table I; 2 and 5 in table II; 4 and 6 in table IIT;
7 and to in table IV.
TABLE I
TRANSPIRATION DATA OF VARIETIES OF GRAIN SORGHUMS® IN BOG WATER
Marcu 6-24, 1910
cnranane ‘ dears Stalag for
: Transpiration in Green weight
Variety of of
ariety of sorghum grams produced Pao greece
F MUG ss eS 106.15 2.59 40.95
a Witte Oe 5 oe as QI.05 2.18 42.98
a Powe MMO. 2S. csi 86.70 2.87 30.17
i. SPAR ER es a Seek 78.05 1.89 41.70
White Kowliang............ 78.32 2.92 26.08
6 Blacknul Fase. 6... ..s. 69.95 1.40 49.85
2 asus A 55-605 1.46 37-98
eee ees 52.90 1,28 41.34
Atmometer: 25 cc. daily average
TABLE II
TRANSPIRATION DATA OF VARIETIES OF ALFALFA IN BOG WATER
May 6-26, 1910
. Transpiration in Green weight cr as =
Variety of alfalfa pein sienien te oon ot
1. Medicago falcata .......... II.50 1.48 7.77
2. Var. 16399 (Washington) .. 11.86 2.28 5.20
So Var 20sec oe 8.72 0.99 8.80
4. Var. 9350 (eres). 7.32 0.50 12.40
5. Sand Lucerne 20457........ 11.93 2.2% 5.40
Atmometer: 18.9 cc. daily average
It is quite generally known that rapid growth is usually accom-
panied by active respiration, and hence slowly developing plants
are able to increase in dry weight upon a smaller quantity of water
absorbed and transpired. It seems clear from the normal appear-
ance of the roots of these plants, that the injurious substances have
an entirely different effect upon some varieties of the plants with
BALL, C. R., The history and distribution of sorghum. U.S. Dept. of Agricul-
ture, Bur. Plant Industry, ones 175, 1910
1912] DACHNOWSKI—BOG PLANTS 509
the smaller transpiration value from that observed in others. The
marked difference is undoubtedly due to the nutritive value of
the assimilable organic compounds. This particular feature of
variability in nutritive metabolism is so characteristic and strik-
TABLE III
TRANSPIRATION DATA OF SPECIES AND VARIETIES OF BEANS IN BOG WATER
EBRUARY 24—MARCH II, IQIo
Sieci AS Transpiration in Green weight Water required for
pe oe varieties produced I gram =
ie DOMON 29h. 6 6k cs 150.68 3.95 40.18
2 Dolichos 85 Ene See ae ones 99.54 1.52 65.61
Phaseolus mungo var. 18310. 66.46 1.34 49.59
‘ Wa R000. ee 69.98 2.32 30.16
— MUGS ee. 56.35 1.24 45.32
é. Se a 36.57 1a 32.23
Atmometer: 7.3 cc. daily average
TABLE IV
TRANSPIRATION DATA OF WHEAT PLANTS IN SOLUTIONS OF STERILIZED BOG WATER
AND PEAT, INOCULATED WITH BOG BACTERIA
CH 31—APRIL 15, IgIo
po ges welelt Water required for
Culture a in ayo" — ann of
te G OPE ss cc os 12 1.16 10.37
We Re BO oe es 8.90 0.80 Ir.12
et ea oh eee ee 14.90 1.14 13.07
ce ne ee OE ESET ERG: 13.08 °.94 13.91
CEN OAS OU are eae nee 15.65 0.98 15.96
We Gete se 2 15.25 0.93 16.30
7. ©. vy (fumes). cscs. 17-93 1.60 11.20
oe hn 37 Cin) Co. 17.40 1.01 17.22
ha —? 9. Pa sagen 18.07 —< vies
Or Ge Se une) oe 25. 2.3 #05
tr. Alder tubercles............ Fe 2.20 22.86
12. Mixed culture of above... . 67.48 1.92 35.14
Atmometer: 11.7 cc. daily average
ing in agreement with the several experiments which were con-
ducted, that analyses with reference especially to the ratio between
the carbon and nitrogen content of the plants are much to be
_ desired. Experiments on the availability of nitrogen in peat have
been made by a number of workers, but mostly upon sun-dry or
510 BOTANICAL GAZETTE [DECEMBER
kiln-dry peat, the solubility of which in water is very low. The
results confirm, however, both an increase in the production of
dry matter in plants, and of dry matter relatively richer in the
amount of nitrogen, as compared with the percentage in plants from
soils lacking peat.?
Additional evidence of a similar nature is derived from experi-
ments of more recent date with pure cultures of isolated bog organ-
isms growing in sterilized solutions of bog water and peat (table
IV, nos. 7 and 10), and from the preliminary work upon peat com-
posted with the bacterial life from stable manure. They confirm
the earlier experiments and also demonstrate the ability of some
mycelial bog fungi and the organisms in alder tubercles* to increase
transpiration and green weight of wheat plants about 200 per cent
above that in untreated bog water. Normal appearance is here
associated with a uniformly higher absorption of the solution,
amount of transpiration, and green weight produced, and with the
healthy condition of roots and leaves. The wheat plants in the
cultures have the usual osmotic pressure isotonic with about a
0.2 to 0.3 normal potassium nitrate solution. Difficulty in
absorption and tolerance or the xerophytism in bog plants do not
seem to be correlated with high osmotic pressure.”
The point of most importance which should be noted in this con-
nection is the obvious difference in the water requirements of the
plants. Water and its solutes, whether organic compounds or
inorganic salts, are as a general rule taken up in a different ratio
from that existing in the substratum. The existing differences
in the various colloids of cells would naturally tend toward inequali-
ties in the amount of water or solutes absorbed and held by the
tissues of the different varieties of species; the diosmotic properties
of the protoplasmic membrane, differing according to the species
9» Haskins, H. D., The utilization of peat in agriculture. Massachusetts Sta.
Rept., pt. 2:39-45. 1909.
Lieman, J. G., Report of the soil chemist and bacteriologist of the New Jersey
Agricultural Experiment Station. 1910. pp. 188-195.
10 Spratt, E. R., The morphology of the root tubercles of Alnus and Elaeagnus
and the polymorphism of the organism causing their formation. Ann. Botany 26:
119-128. IgI2.
« Firtinc, H., Die Wasserversorgung und die osmotischen Drukverhiiltnisse
der Wiistenpflanzen. Zeitschr. f. Bot. 3:209—-275. 1911.
1912] DACHNOWSKI—BOG PLANTS 511
used as an indicator, would further determine the difference and
variability in absorption, resistance, or tolerance. Inasmuch as
the amount of mineral salts in bog soils and the amount used in
the growth of bog plants is very small, and since the lack of larger
quantities is not a factor in the succession of bog associations, the
most fundamental distinction is that which controls the supply
of available water. A method of determining the ratio between
ash and the yield in organic compounds on the basis of the water
requirement of plants for the period of their growth would have the
merit of convenience, and, it must be admitted, the accuracy which
is often questionable in the unit employed and as preferably
expressed in agricultural literature. The unit of water require-
ment now used in agricultural texts for ten different economic
species is 450 pounds of water for one pound of dry matter pro-
duced. Data of that character do not place the classification and
comparison of soils, correlations with fertility or with age of plant,
maximum growing period, and seasons on a measurable basis.
The unit is numerically inaccurate and does not express the funda-
mental and causal relations:
Experiments upon the transpiration value of bog plants in
relation to structure and habitat, to be published later, have
shown that the data cannot always be expressed satisfactorily in
the gm*h system. ‘Transpiration is a reciprocal relation. It is
affected by the conditions which react upon the absorbing roots,
and it is associated with chlorophyll activity and the absorption of
carbon dioxide in the vertical gradient. Transpiration in the lower,
more humid stratum of a bog meadow is often slight for days at a
time. The luxuriousness of the vegetation and the amount of
dry matter produced do not vary in this case with the transpiration
quantity, but with protoplasmic permeability and the specific
metabolism, permitting of exchanges by solubility, and with the
active enzymic agents within the cells which effect the assimilation
or the destruction of the substances in the external medium.
Whatever the cause of the differential permeability,” solubility
™CzaPek, F., Uber eine Methode zur direkten i der Oberflachen-
spannung der Fissinehatt von Pflanzenzellen. Jena
E . W., Zur Kenntnis der dentin — der
Plasmamembran. Ber: Deutsch. Bot. Gesells. 29: 247-260. 1
512 BOTANICAL GAZETTE [DECEMBER
of the substances in the medium and in the plasmatic membrane
is prerequisite to penetration (osmosis) into the living cells.
In previous publications on the factors by which the present
bog vegetation is determined the writer pointed out that different
species of cultivated plants show marked differences in the degree
of sensitiveness to the toxic conditions of a bog habitat. That the
stunted plants in these experiments have not lost their capacity
for absorption and growth can be readily demonstrated. The
plants resume their natural functions as soon as they are placed in
dilutions less fatal in its effects. In contrasting the differences
in physiological activity it was further shown that various phases
of absorption and transpiration resulted from the progressive addi-
tion to the medium of chemically inert filtering materials. Types
of soil were used ranging from the weathering products of soil-
forming rocks to the completely oxidized products characteristic
as the final residue. Incidentally it was shown that the normal
growth of the plants in the uncontaminated soils was replaced by
an abnormal retardation. In the main the study indicated that
upon extraction of the injurious substances by means of insoluble
adsorbing bodies, not only the differences between different species
as to their tolerance and resistance were less pronounced, but
also the differences in toxicity existing between the several zones
within the same habitat. The selective action of the habitat was
shown to be greatly diminished upon the removal of the injurious
organic substances accumulating in the peat substratum. The
conclusion was drawn that the relative power in bog plants for
absorbing or rejecting the injurious constituents of bog soils and
bog water was therefore the limiting factor, controlling the survival
value of invading species and of plants native to the habitat.
The roots of bog xerophytes are not much shorter than those of
other plants; the lateral roots develop extensively, and the preva-
lent direction of root growth is horizontal rather than downward.
This reaction cannot be regarded as one due to low soil tempera-
ture or to a slight oxygen content. The inhibitory factor for root
growth which increases with depth is the reducing action of the sub-
stratum and the incomplete disintegration of organic compounds.
It is now well known that certain root enzymes are oxidizing agents
1912] DACHNOWSKI—BOG PLANTS 513
which assist in the destruction of deleterious compounds in soils of
an organic nature, and that the oxidizing action becomes lessened
when the injurious organic substances are in excess. The wide
variations in this functional reaction are probably of greater impor-
tance than external factors. It seems a tenable hypothesis, there-
fore, that the survival or the extinction of invaders may depend
more upon the degree of functional plasticity than is generally
admitted.
The experiments here cited furnish nothing more than an indi-
cation of the relative importance of some of the factors involved.
The weight of evidence is obviously incomplete, for numerous
important considerations have received no attention whatever in
_ the present paper. The problem of absorption is not one of simple
solution, but an intricate and coordinated process, and much needs
to be known of the energy relations between plants and habitat
and the organization of the protoplasmic membrane of absorbing
organs. From the present study the following relations may be
summarized:
1. Physiological investigations of peat soils have brought out
clearly the fact that the character of the obligate bacterial flora
and the nature of the organic compounds produced form a very
important factor in the relative fertility of peat soils, in the causes
of vegetation succession, in the distributional and genetic relation-
ships of associations, and in the characteristic xeromorphy of
both ancient and modern bog vegetation.
2. In view of the widely differing behavior of agricultural
varieties in a bog water solution, and the interesting observation
that the plants respond differently to the same solution, the con-
clusion is inevitable that here the source of the difference must
logically be looked for not in the solution alone, but in the condition
of the plants as well.
3. Since certain of the organic compounds eventually penetrate
the protoplasmic membrane of absorbing organs and inhibit
growth, it is evident that much importance must be ascribed to the
influence exerted upon the plasmatic membrane, to the consequent
differences in its diosmotic properties, and to the pathological
changes induced which accompany the absorption of the injurious
substances.
514 BOTANICAL GAZETTE [DECEMBER
4. Some plants in contact with peat soil solutions may cause
the organic constituents to be precipitated in an insoluble form.
5- In other plants the different organic carbon and nitrogen
compounds arising in peat through the activity of microorganisms
may be absorbed and assimilated. The chemical formula and
transpiration data alone afford no indication of the physiological
importance of the substances, hence the nutritive value of these
compounds should be estimated on the basis of the total water
requirement of a plant during its period of growth and the ratio
between carbon, nitrogen, and ash in the plant.
6. The phenomena of absorption and tolerance of plants in bogs
deal plainly not with osmotic pressure relations so much as with
considerations of the permeability of the absorbing protoplasmic
membrane, its power of endurance, and its ability by enzymic
action either to absorb and assimilate or to transform injurious
bodies into insoluble, impermeable compounds.
7. The organic disintegration substances in peat soils, while
inhibitory to agricultural plants, have little or no effect upon
certain xerophytic plants. It is concluded, therefore, that they
may be positive forces not only in producing the natural succes-
sion of vegetation in bogs, but also in determinating xeromorphy
and the associated relation of the members, within each group,
which best succeed upon peat deposits. These organic substances
play the differentiating réle and are a cause of the infertility of
peat deposits even when the amount of air’ and water in the soil
is abundant and the temperature and humidity conditions are
favorable to growth.
It is needless to point out that these facts have an important
bearing on the agricultural exploitation of peat deposits and on
the subject of the proper value of peat land to agriculture.
It is a pleasant duty to record my thanks to Mr. M. G. DIcKEY
and Mr. M. Corotis for their assistance in obtaining the transpira-
tion data in tables I to ITI.
BOTANICAL LABORATORY
Onto STATE UNIVERSITY
INGROWING SPROUTS OF SOLANUM TUBEROSUM!
C. STUART GAGER
(WITH PLATE XXXVI AND SIX FIGURES)
Description
As is well known, it is not at all uncommon to find tuberization
of the sprouts on potatoes kept over winter in a cellar. The fact
is commonly attributed to the absence of light and the dampness
of the cellar. In the late fall of 1907, a large basket of potatoes,
of the ‘Green Mountain” variety, was placed, for want of a cellar,
in an unheated chamber. There was one east window in the room,
3
Fics. 1-3.—Fig. 1, Various stages of persatene of the sprouts of a potato under
conditions of diffuse ateination n; fig. 2, Young tubers emerging from within an old
seed tuber of Solanum tuberosum (cf. sil 1 hy and 5); fig. 3, Cross-section of a tuber
of Solanum tuberosum with i ingrown spro
and the curtain was ordinarily up, so that the room was neither
dark nor damp. On the contrary, the atmosphere of the room was
comparatively dry. Under these conditions, a number of the
potatoes were found with sprouts in various stages of tuberization,
varying from a slight enlargement back of the tip to well formed
“potatoes” (fig. 1), but in the case of two or three of them, the
* Brooklyn Botanic Garden Contributions. No. 5. The substance of this paper
Was given before the Botanical Society of America on December 29, 1911.
515] [Botanical Gazette, vol. 54
516 BOTANICAL GAZETTE [DECEMBER
sprout-tubers appeared to be emerging through the skin from within
the potato (fig. 2). Closer observation and dissection disclosed
the interesting fact that at least a quarter or a third of the potatoes,
of which there was about a bushel in all, had ingrowing sprouts.
The condition is well illustrated in fig. 3, which is a typical cross-
section.
On careful dissection of many of the tubers, the ingrowing
sprouts were found to ramify in every direction throughout the
Fic. 4.—Tubers of Solanum tuberosum with ingrowing sprouts: the figure at the
right shows the ingrown sprouts emerging through the skin; the figure at the left is
of a dissection, showing rootlets, the marked development of lenticels, and the tuberiza-
tion of some of the branches of the ingrown sprouts within the old tuber (cf. figs. 2
and 5).
tissue of the potato. The atrophied and etiolated bud end retained
the characteristic nutation curvature, but the sprout was frequently
more or less enlarged just back of the tip (figs. 4 and 5). Lenticel-
like openings were well developed in the epidermis of the sprouts,
often giving them the appearance of a cylindrical file.
Numerous fibrous roots grew out from the branches, and they
seemed, for the most part, to be confined in their growth to the
channels made by the stem. As is clearly shown in the right hand
1912] GAGER—INGROWING SPROUTS 517
potato of fig. 4, the internal sprouts would often grow through the
skin and emerge at various points.
The branches tuberized freely, and it was not uncommon to
find five or six, or even more, well formed, but pure white, tubers
of various sizes entirely within the old tuber. In some cases, as
in the right hand specimen of fig. 5, the branches were only imper-
fectly tuberized, and the tip retained its nutation curvature. Often,
as noted above, the young tubers, like the unswollen branches, had
pushed through the skin of the potato and, where exposed to the
air, had developed a characteristic brown epidermis (fig. 4).
Fic. 5.—Dissected tubers of Solanum tuberosum, showing various stages of tuberi-
zation of branches of ingrown sprouts, both within and without the seed tuber (cf.
figs. 2 and 4).
In many instances there was every appearance of a reversal
of polarity of the sprout. This is clearly shown in fig. 6, which
illustrates two “eyes,” the one at the left of a normal potato, the
one at the right of one of the abnormal ones. What has occurred
in the latter appears to be just the reverse of what took place in the
former: roots occur at the distal end of the sprout, where we would
ordinarily expect the terminal bud, and the numerous branches
appear to have developed from the proximal end of the sprout,
Whether this is actually the case or not one hesitates to say. It
is possible that the entire shoot system, shown at the right in fig. 6,
may have developed from a sprout whose tip turned through 180°
518 BOTANICAL GAZETTE [DECEMBER
toward the surface of the potato and penetrated the parent tuber
from without. But it is only the a-priori improbability of a reversal
of polarity that makes the writer hesitate to declare it. The evi-
dence clearly indicates it, but the evidence is not all in.
Fic. 6.—Sections through sprouting tubers of Solanum tuberosum: at the left, a
normal “‘eye’’; at the right, an “eye” with sprouts ingrown and indicating a reversal
of polarity of the branch.
Discussion
What caused the ingrowing of these sprouts it is difficult to
say. The fact that the potatoes were stored in a room where the
air was much drier than that of cellars, where potatoes are usually
kept, suggests that the low humidity was at least a contributory
cause. But equally interesting is the question of how the sprouts
made their way through the tuber. Were the channels through
which they grew formed by the digestion of the potato tissue by an
enzyme secreted by the tip of the sprout; or did the channels result
merely from the mechanical pressure of the sprout as it elongated?
It will be recalled that a similar problem arose in connection
with the endogenous emergence of lateral roots. Considerable
difference of opinion has existed on this question. The first
physiological study of the emergence of lateral roots appears to have
been made in 1871, by REINKE {Q), who stated that the channel
1912] GAGER—INGROWING SPROUTS 519
through the cortex was digested by a substance secreted by the
emerging root. The same conclusion was reached later by Von
HONE (12) and by Van TieGHem (11). Neither REINKE’s nor
Van TiecHem’s figures, however, show evidence of enzymatic
action. In 1896 CzapEexk (1) reported that he found in the excre-
tions of the roots of higher plants no evidence of any enzymes.
If they are present, the amounts are too small to be detected.
PFEFFER has declared for a mechanical modus operandi, aided by
some activity on the part of the cortical tissue.
In 1894 Perrce (6) found that the roots of Vicia and Pisum
penetrated living tissue by mechanical pressure, unaided by
enzymes. He also states that the radicle of Pisum could enter
through the uninjured periderm of a potato from the outside. In
1903 OLUFSEN (5) reported a confirmation of PErIRcE’s results,
but Ponp (8) was unable to confirm them, and reported negative
results also for Vicia Faba and Lupinus albus. When the periderm
was wounded, the radicles of these seedlings entered easily and
penetrated the parenchymatous tissue. When the periderm was
unwounded, the radicles deeply indented the surface, but never
pierced through. Microscopic examination showed that the peri-
derm cells, and, to a less degree, the hypodermal cells also, were
compressed, but there was no evidence of corrosion. ‘The advan-
cing root formed callus, — —_—- the periderm is wounded the
callus does not form. ... .
In one of Ponn’s experiments a potato tuber was cut in two and
the outer surfaces placed together and held firmly in this position
by string. Then a channel was made in one half to within a few
millimeters of the skin, and the radicles of seedlings inserted. The
whole was then incased in gypsum. The radicles perforated the
periderm of the first half from the inside, and were thus brought
into contact with the outside of the periderm of the other half,
but this they failed to penetrate. From these observations Ponp
concludes that the mechanical push is too weak to accomplish
penetration from without. ‘‘Microscopical examination of the
flesh of a potato showed no evidence of any digestive action.”
In a similar manner Ponp found that an elongating radicle
of Lupinus albus was unable to penetrate through the uninjur
520 BOTANICAL GAZETTE [DECEMBER
epidermis of another Lupinus radicle. The second radicle was
always deeply indented, but no signs appeared of corrosion of the
surface. If the surface was even very slightly wounded, as for
example by pricking it with a fine glass point, then the other
radicle easily entered and passed entirely through without callus
formation. The penetrating root, however, was never found to
pass through the central cylinder, but always around it, thus indi-
cating more resistance than that offered by the cortex. The cylin-
der was indented, but there was no evidence of corrosion of its cells.
Starch grains did not appear digested either by autolysis or by the
entered root. The results of mechanically forcing a glass rod into
the tissue could not be distinguished from those produced by an
entering radicle. The conclusion drawn was that the mechanical
push was not sufficient to pierce the cuticle from the outside, and
that “‘if the radicle or the lateral root secretes an enzyme, such
enzyme has no digestive action upon the cuticle.”
As in the case of the roots, so with the potato, the course of
procedure for a solution of the problem is clearly indicated. If the
channels were the result of enzymatic action we would expect to
find, first, in the tips of the sprouts an enzyme able to digest the
potato tissue; second, evidence of enzymatic action in the tissue
itself; third, absence of any evidence of mechanical pressure; and
finally, we might expect to find the epidermis of the ingrowing
sprout modified in the direction of glandular epithelium. If the
sprout merely pushed its way through the tissue of the tuber, we
would find no signs of enzymes or of enzymatic action, but rather
positive indication of mechanical pressure.
Physiological and anatomical study
A considerable quantity of tips of the ingrowing sprouts was
given to Professor Wit11AM J. Gres, of Columbia University, who
kindly offered to have them tested for enzymes. While waiting
for a report on this test, microscopic sections of the sprouts were
examined, to see if there was any modification of the epidermis in
the direction of a glandular epithelium, such for example as that
on the scutellum of the embryo of Zea Mays. As is clearly shown
in A and B of plate fig. 1, a well developed columnar epithelium was
1912] GAGER—INGROWING SPROUTS 521
found, and since the epidermal cells are more nearly isodiametric
in normal sprouts, it was expected that the chemica] examination
would disclose the presence of enzymes. Such however was not
the case. No enzymes were detected, and this experience empha-
sizes the truth that any inference as to the function of an organ or
tissue, based upon structure alone, cannot always be relied upon,
unless substantiated by positive evidence.
Further confirmation of the absence of enzymatic action was
obtained by examining microscopic sections of the walls of the
channels made by the sprouts in the tissue of the tuber. There
were no signs of corrosion of the cell walls nor of the starch grains
within the cells (plate fig. 2).
Only one alternative remained: the sprouts made their way
through the tissue of the tuber by mechanical pressure alone.
This conclusion found abundant confirmation. The wall cells of
the channels made by the sprouts were greatly compressed by the
advancing tip (plate figs. 2 and 4). In light of the studies made on
the mode of emergence of lateral roots, it is instructive to compare
plate figs. 3 and 4. This latter figure is a detail of the tissues at
the point marked C in plate fig. 1. Fortunately, at this point a
lateral root had begun to develop, and it is clearly seen (fig. 3), not
only that the walls of the cortical cells show no signs of enzymatic
action, but that they are evidently compressed by the advance of
the developing root tip. The paths of the ingrowing sprouts and
of emerging lateral roots are evidently made in the same manner,
namely by mechanical pressure alone, unaided by enzymatic action.
Experimental production of ingrowing sprouts
But how did the ingrowing sprouts start? Do they, as sug-
gested above, represent normal sprouts that for some unexplained
reason turned their tips toward the tuber and penetrated through
the skin? There is no evidence for this view. In numerous
cases where the “eyes” were deeply indented, small sprouts grew
out laterally until their tips came into contact with the skin of
the potato. But, as in the case of Ponb’s attempt to cause one
root of Lupinus to penetrate another held firmly at right angles
to it, so here the surface of the potato was indented by the tip
522 BOTANICAL GAZETTE [DECEMBER
of the sprout, but no case of penetration was observed: At the
writer’s suggestion, Miss Lucite KereEne,? then a senior in the
University of Missouri, endeavored to secure the penetration of one
potato by the sprouts of another. The two tubers were bound
tightly together with stout cord, and buried in moist sphagnum.
In no case were the sprouts successful in penetrating through the
uninjured skin of the adjacent tuber, though the latter was indented.
However, if the sprouts were placed against the cut surface of
another potato, they entered easily, made their way through the
parenchymatous tissue to and through the skin at the farther sur-
face. That the sprouts can easily penetrate the cortex from
within, though not from without, was shown by the abnormal
cases where such penetration: was general (fig. 4). Had enzy-
molysis been a factor, the sprouts might as easily have penetrated
from without. The experiments with roots, as noted above, gave
analogous results.
The observed facts will not admit of a definite denial] of reversal
of polarity. Many of my dissections cannot reasonably be inter-
preted in any other way, but it still seems possible, though not
always probable, that the ingrown sprout arose as a lateral branch
starting at the very base of the main sprout and below the skin of the
tuber. ‘This hypothesis at least does not make as large a draught
on pure faith as one involving the conception of a reversal of polar-
ity in the shoot. DEtTMER (2) long since called attention to the
fact that while the intensity of polarity varied greatly with different
species, it was especially well marked in the case of Solanum
tuberosum.
The cause of tuber-formation
What caused some of the ingrown sprouts to form tubers?
The answer to this question is of course bound up with the larger
question as to why potato branches ever tuberize. The literature
bearing on this problem was discussed by the writer (3, 4) in 1906,
and need not be reviewed here. Reference may again be made,
however, to the suggestion of BERNARD that the formation of tubers
is due to a species of Fusarium, endotropic with Solanum tuberosum.
2 Miss Keene also found a similar case of ingrowing sprouts in Montana, but
the sprouts were only slightly branched, and formed no tubers within the old potato,
Ig12] GAGER—INGROWING SPROUTS 523
This suggestion was tested experimentally by JUMELLE, but with
negative results. Quite evidently this factor does not enter in the
tuberization of branches of the ingrown sprouts. GOEBEL cites
tuber-formation as an illustration of “qualitative correlation,”
stating that it is a function of the relation of the branch to the whole
shoot system, its underground position, and the material supplied
to it.
It seems to the writer that an attempt to explain such a dee
seated character as the formation of tubers by potato plants is like
trying to explain the cornness of corn. We may ascertain experi-
mentally what external conditions or combination of circumstances
must be realized in order that tubers may result, but that they
form at all is because the plant is Solanum tuberosum, rather than
Pisum sativum or Solanum Dulcamara. To use a recent and very
valuable terminology, the formation of tubers by Solanum tubero-
sum, or by any other tuber-forming species, under suitable environ-
mental conditions, is an expression of the genotypical constitution of
the plant. Further explanation than this lies far in the future.
Conclusion
t. Ingrowing sprouts of Solanum tuberosum make their way
through the tissue of the tuber not by enzymatic digestion of a
channel in the tissue, but by the mechanical pressure which accom-
panies growth in length.
2. Potato sprouts do not elongate with force sufficient to pene-
‘trate through the uninjured “skin” of the potato tubers from the
outside, but they easily penetrate the skin from the inside.
3. A reversal of polarity in ingrowing potato sprouts is not
definitely demonstrated, but there is evidence pointing to this
conclusion.
4. Tuberization of branches takes place freely on ingrown
sprouts of Solanum tuberosum.
5. The formation of tubers on Solanum tuberosum is a function
of external conditions plus the genotypical constitution of the
species.
Tae Brooxtyn InstiruTE OF ARTS AND SCIENCES
BRrooKtyN Botanic GARDEN
524 BOTANICAL GAZETTE [DECEMBER
LITERATURE CITED
1. CzAPEK, F., Zur Lehre der Wurzelausscheidungen. Jahrb. Wiss. Bot.
29:321-390. 189
2. DETMER, W., Prattical plant physiology. Eng. trans. by S. A. Moor.
p. 508. London. 1808.
3. GAGER, C. STUART, —— in Solanum tuberosum in daylight.
Torreya 6:181-186.
, Further aie. on du formation of aerial tubers in Solanum. Tor-
reya ee 212. 1906.
5. OLUFSEN, L., Untersuchungen iiber oo an Kartoffel-
ollen. Bo * Cent. Beih. 15: 267-308. rR.
6. Peirce, G. J., Das Eindringen von Werks | in lebendige Gewebe. Bot.
Zeit. 52:169-176. 18094.
7. PrerFerR, W., Druck- und Arbeitleistung durch wachsende Pflanzen.
Abhand. Kénigl. Sachs. Gesells. Wiss. 203: 235-474. 1893.
8. Ponp, R. H., Emergence of lateral roots. Bot. Gaz. 46:410-421. a
9. REINKE, J., Untersuchungen iiber Wachsthumgesichte und Morphologie
der Phanerogam-Wurzel. Hanstein’s Bot. Abhand. Gebiet Morphol. und
Physiol. 13: 1-38. 1871.
to. VAN TIEGHEM, P., and Doutiot, H., Recherches comparatives sur l’origine
des membres endosines dans les plentes vasculaires. Ann. Sci. Nat.
Bot. VIL. 8:1-660. pls. 1-go. 1888.
11. VAN TIEGHEM, P., Traité de botanique. Deuxiéme édition. pp. 709-711.
Paris. 1891.
12. Von Héne, H., Uber das Hervorbrechen endogener Organe aus dem
Mutterorgane. Flora 63: 227-234, 243-257, 268-274. 1880.
i
EXPLANATION OF PLATE XXXVI
Solanum tuberosum
1.—Outline of a longitudinal section of an ingrown sprout: A and B,
ade structurd at the regions marked A and B in the outline, showing well
developed columnar epithelium.—Zeiss oc. 4; obj. D.
Fic. 2.—Longitudinal section through the tip of an ingrown sprout, with
adjacent tissue of the seed tuber, showing mechanical compression of the cells
of the tuber by the growing sprout and absence of any evidence of corrosion of
either cell walls or starch grains; the breaks in the cell walls are artifacts;
many of the starch grains have fallen out of the section.—Cf. figs. 3 and 4.—
Zeiss oc. 4; obj. AA., lower lens only.
Fic. 3.—Early stains in the development of a root within an ingrown
sprout; this section was-taken at the area marked C in fig. 1; note the com-
pression of the cortical cells by the advancing root.—Cf. figs. 2 and 4.—Zeiss
oc. 4; obj. AA.
Fic. 4.—Cross-section through a seed tuber, showing compression of the
wall cells of a channel made by an ingrown sprout.—Cf. figs. 2 and 3.—Zeiss
oc. 4; obj. AA.
PLATE XXXVI
V
yen wae
Cotr Re
a
a
GAGER on INGROWING SPROUTS
THE ABORTIVE SPIKE OF BOTRYCHIUM
CONTRIBUTIONS FROM THE HULL BOTANICAL LABORATORY 164
O°: O. SPteLrAny
‘(WITH TWENTY-ONE FIGURES)
Interest in the study of the vascular anatomy of the Ophioglos-
saceae has increased since CHRYSLER’S work’ on the nature of the
fertile spike appeared in 1910. He made the vascular supply of
the leaf the basis for concluding that the fertile spike represents two
fused basal pinnae. The nature of the vascular supply of the
abortive spike has so far received no special
attention.
This investigation was undertaken to deter-
mine the origin and nature of the vascular
supply of the abortive spike, and to compare it
with that of the sterile pinnae and the fertile
spike. CHRYSLER found that the series of
changes undergone in the origin of the strands
to the sterile pinnae were precisely the same as
those for the fertile spike.
The material studied was Botrychium virgini-
anum, the species from which CHRYSLER made 1
his figures illustrating the origin of the strands Fics. 1, 2.—Fig. 1,
to the fertile spike and sterile pinnae. The
abortive spike is of very common occurrence in abortive spike and _
this species. It appears on the adaxial side of -~ pair of pinnae
the petiole as a minute structure about 2 cm. t off; one-ha
below the first pair of sterile pinnae (figs. 1, 2).
The fertile spike, however, always comes off
from the main axis slightly below the first pair of pinnae. The
elongation of the petiole after the abortive spike separates from
the axis leaves it some distance below the first pair of pinnae.
' CurysLer, M. A., The nature of the fertile spike in Ophioglossaceae. Ann.
Botany 24:1-18. figs. 1-16. pls. 1, 2. 1910.
525] [Botanical Gazette, vol. 54
lateral view of same.
526 BOTANICAL GAZETTE [DECEMBER
Serial sections were made throughout the petiole from about
8 cm. below the abortive spike to the place where the first pair of
sterile pinnae appear. Figs. 3-10 show the changes undergone in
Fics. 3-10.—Diagrams illustrating the origin of the vascular strands to the
abortive spike, sande with the aid re an Abbé comers lucida and reduced one-half in
reproduction: di 1] fig. 3, 7.6cm.; fig. 4,5.3cm.;
g. 5, 2.1 cm.; fig. 6, 4 mm.; figs. 7 and 8, about 1 mm.; figs. ound Io, opposite
= abortive ephicas adaxial side of petiole placed upward; x rs.
tgt2] STOLAND—SPIKE OF BOTRYCHIUM 527
the vascular strands relative to the supply of the abortive spike.
The vascular strands are all of the concentric type throughout the
aerial part. About 8 cm. below the abortive spike the leaf trace
consists of three pairs of strands (fig. 3, d, e, f), one large lateral
pair (fig. 3, d), and two pairs on the abaxial side (fig. 3, e, f). One
of the pairs (fig. 3, f) soon unites with the abaxial margin of the
lateral strands (fig. 4). The second pair (fig. 3, e) remains free to
within 1 cm. of the abortive spike, where it also unites with the
abaxial margins of the lateral strands (fig. 6). The vascular
strands of the abortive spike originate about 8cm. below the
point where the spike leaves the petiole. The adaxial arms of the
lateral strands become hooked (fig. 3) and soon a curved strand
(figs. 3-7, a) is cut off so that a gap is left in the sides of the leaf
traces (figs. 4-6, g). From each side of these gaps a small strand
breaks off to supply the abortive spike (figs. 4-8, b, c). The out-
line of these strands appears below the gap, so that they really
originate from its base (fig. 3, 0).
There are then four strands, that is two on each side, that supply
the abortive spike. They adhere to the sides of the gap for some
distance, but finally break off, one 5 cm. (figs. 4, 5, 6), the other
about 2 cm. (fig. 7, c) below the abortive spike. From this point
they remain as separate strands running along the gap and finally
enter the abortive spike (figs. 9, 10, 6, c). The gaps in the lateral
leaf traces close about 4 mm. below the abortive spike (fig. 8). At
about this point the two lateral traces (fig. 8, d) each divide into
two equal strands. The adaxial strands thus formed are hooked
(figs. 8-10, hk). These adaxial hooked strands each divide into
two equal parts (fig. 12, A’, 6’) of which the outer pair (6’) diverge
to pass out to the pinnae (figs. 11-15, 6’). Another pair of strands
(figs. 13, 14, c’) arise from the adaxial margin of the lateral strand
(figs. 13, 14, d), so that each pinna has two strands. Where these
strands (c’) leave the leaf trace the gap becomes closed, strand a’
uniting with strand d. The leaf trace above the origin of the first ,
pair of pinnae consists of two lateral strands (fig. 15, d). By a
study of figs. 3-15 it will be seen that the same series of changes
occurs in the origin of the vascular supply of the sterile pinnae as
for the abortive spike.
528 BOTANICAL GAZETTE [DECEMBER
In some of the leaves examined the vascular supply of the
abortive spike consisted of a single pair of strands, that is, one
from each side, but in such cases there were two pairs of strands for
Fics. 11-15.—Diagrams following the series shown in figs. 3-10, illustrating the
origin of strands which supply the first pair of sterile pinnae; fig. 11, 5 mm. above
abortive spike; fig. 12, 1 cm. above it; figs. 13-15, opposite the ek where the
pinnae diverge.
1912] STOLAND—SPIKE OF BOTRYCHIUM 529
each pair of sterile pinnae. As shown in figs. 16-18, the strands
of the abortive spike may have well developed primary xylem in
the lower stretches (fig. 16), but farther up the xylem gradually
fails to appear (fig. 17), and before they turn outward no xylem is
formed. Here the strands are distinguished by their narrow elon-
gated cells. In other cases no traces of xylem could be found
throughout strands of the abortive spike.
7S
eSN
Fics. 16-18.—Transverse sections through the strands of the abortive spike,
showing development of xylem; fig. 16, 12 mm. below abortive spike; fig. 17, 4 mm.;
fig. 18,3 mm.; X210.
If figs. 3~15 are compared with CHRYSLER’Ss figures showing the
origin of the strands to the fertile spike, it becomes evident that
the changes are essentially the same. A few exceptions may be
noted. The first strand (a and a’) which breaks off on the adaxial
side does not unite with the inner face of the large strand as it does
in the case of the fertile spike. The gaps left by the strands to the
abortive spike are much more evident. These are shown in the
photographs of models in figs. 19-21. These models show only
one-half of the vascular supply. In fig. 19, which shows the inner
530 BOTANICAL GAZETTE [DECEMBER
face of the lateral strand, the two strands to the abortive spike are
very evident, with the long gap behind them. ‘The gap is seen even
better in fig. 20, which shows also part of the adaxial face. Fig. 21
shows the adaxial face of the model with the two narrow strands
to the abortive spike obscuring the gap. Four such strands are
present in the petiole, but the model shows only one-half of the
19 20 21
Fics, 19-21.—Photographs of model of the leaf traces on one side of the petiole
in region where strands to abortive spike originate; fig. 21, adaxial face.
vascular supply. The pinnae of the leaves bearing the fertile spike
usually have only one vascular strand, while those that accompany
the abortive spike have two in all cases examined.
The breaking up of the leaf traces into curved rows of bundles
below the origin of the strands to the abortive spike does not occur
as regularly in the petioles with the fertile spike. This condition
is described by CHRYSLER for Ophioglossum and Helminthostachys,
1912] STOLAND—SPIKE OF BOTRYCHIUM 531
where the vascular supply of the fertile spike is derived from curved =
rows of strands.
Summary and conclusions
1. The leaf trace of the petiole bearing the abortive spike con-
sists of several bundles instead of two bundles as usually found in
the petiole bearing the fertile spike.
2. The vascular supply of the abortive spike consists of two or
four strands arising from the edges or the base of the gap in the
leaf trace.
3. The pair of sterile pinnae following the abortive spike are
supplied by two pairs of strands originating in the same way as
those for the abortive spike.
4. Xylem may or may not appear in the strands to the abortive
spike, but it never appears throughout the entire strand.
5. The difference between the origin of the strands to the
abortive spike from those to the fertile spike is very slight.
6. The nature of the vascular supply of the abortive spike
supports CHRYSLER’S contention that it represents two fused basal
pinnae.
This work was undertaken at the suggestion of Professor
CouLter and under the direction of Dr. CHAMBERLAIN, and I wish
to express my appreciation for their valuable suggestions and criti-
cisms. I also wish to express my thanks to Dr. M. A. CHRYSLER
for valuable criticism.
Uviversity or CHICAGO
PLANTS WHICH REQUIRE SODIUM
W. J. V. OSTERHOUT
(WITH TWO FIGURES)
It has long been customary to regard sodium as necessary for
animals but not for plants. In the light of our present knowledge
of the réle of inorganic salts, it is clear that this distinction between
plants and animals is of fundamental importance, if it be true in all
cases; but if exceptions occur, its significance largely disappears.
The experiments which are described here were undertaken in
order to learn whether there are cases in which sodium is as neces-
sary for plants as for animals.
One flowering plant was studied, and Giver genera of algae,
among which were representatives of the green, brown, and red
algae. The investigation included species from the Atlantic and
the Pacific
The method consisted in replacing the NaCl of the sea water by
one of the following substances in turn: NH,Cl, CsCl, RbCl, LiCl,
KCl, MgCl, CaCl, SrCl,, BaCl,,t MgSO,, and K,SO,. After some
preliminary experiments it became evident that the best substi-
tutes for Na are Ca, Mg, and K. An attempt was then made to
get better results by using these as substitutes for NaCl in the
following combinations (the figures refer to molecular proportions
as shown in the table): 500 MgCl,+500 CaCl,, 250 MgCl.+750
CaCl, 500 KCl+500 CaCl, 667 KCI]+333 CaCl, 910 KCl+o1
CaCl..
All the salts were carefully tested before using and were recrys-
tallized when necessary. The water was twice distilled from glass
without the use of rubber or cork stoppers; in place of these a
plug of absorbent cotton was employed. The water thus pro-
duced was not toxic to such test objects as Spirogyra and the root-
hairs of Gypsophila, and its quality was further shown by the fact
* The introduction of BaCl, and SrCl, produced precipitates of BaSO, - SrSO,
which were allowed to remain at the bottom of the dish during the experimen
Botanical Gazette, vol. 54] [532
1912] OSTERHOUT—PLANTS AND SODIUM 533
that Phyllospadix after being transferred directly to it from the
sea water lived for 47 days.
All the solutions were made neutral to phenolphthalein before ©
being used. The material was placed in glass dishes in diffused
light and kept covered to exclude dust.
The average temperature in experiments with the Pacific
species was about 20° C. and was not subject to much fluctuation.
In the experiments on the Atlantic coast the jars containing the
plants were partly submerged in running water during the entire
period of the experiment, and the temperature did not vary far
from 20° C,
It is very important to avoid an excessive amount of light.
The optimum must be determined in each case by experiment, but
is usually less for algae than for flowering plants.
The plants lived much longer in sea water (whether natural or
artificial) than in any solution in which the sodium of the sea water
was replaced by some other substance. The best substitutes for
Na are Ca, Mg, and K. The accompanying table shows the length
of life of the plants in solutions made up with these substitutes.
It is evident that we cannot say that one of these substitutes is
better than another unless we also specify what plant is being
experimented on. With one plant Ca fills the place of Na better
than anything else, while with another K proves better; with still
another Mg is better; and in still other cases combinations (for
example, Mg+Ca or K+Ca) are advantageous.
Great diversity was observed among the different species in
respect to their behavior toward the other substances which were
employed as substitutes for NaCl. To Phyllospadix the substitu-
tion of Li in place of Na is much more injurious than that of Rb,
but just the opposite is true of Ulva, while the other plants seem
to be injured about as much by Li as by Rb. Similar diversities
are found in the behavior of the plants toward the other salts.
These facts are important in so far as they give us a clue to the
specific action of salts in life processes; this subject will receive
further discussion in a subsequent paper.
All the different plants agree in showing that the replacement
of Na by Ca, Mg, or K, all of which are present in considerable quan-
534 BOTANICAL GAZETTE [DECEMBER
tity in sea water, is less injurious than the introduction of such
substances as NH4, Ba, Sr, Cs, Rb, and Li.
Some attempts were made to obtain a better solution by combi-
nations of MgCl.+MgSO,+KCl+CaCl, in the proportions in
which they occur in sea water and also in various proportions
other than those mentioned above. So far, however, no combi-
TABLE SHOWING DURATION OF LIFE IN DAYS
2 | 5
=, 3s 8 =| @ | 33
Culture solution Be g 2 i Be a3 ke E 2
st = - o 6-4
ae | 52 | 28| 88) | 28 | 68
BOS eee eee oa 49 23 4 4 2
Prrnetieee WEE oo ay i ek: Py a eg 4 es y 8
ne - i js as ieee G 102+|134+] 50+) 15+) 17+) 18+) 90+
ificial sea water—
ock solution*
78 cc. MgCl, .375 M
38 cc. MgSO, 375 M'| +1000 cc
22 Cc. Lore .375 M NaCl .375 Mj102+/134+] 50+] 15+) 17+) 18+) 90+
to cc. Ca’ :
Stock solution-+ tooo cc. CaCl, .375 M| 56 | 52 | 16 3 5 Rat 32
Stock solution+ t1ooocc. MgCl, .375 M| 52 | 52 | 10 2 5 a}: 30
Stock solution+ 1000 cc 1 ] s | a 8 I 2 ea
Stock solution+ 1000 cc. MgSO, .375 M| 47 | 47 8 2) 2 - baa
Stock solution+ 1000 < 7 187 60 | 2r 6 I 2 I os
‘ -375 1
Stock solution+ a5 pam Cech. bd ml 52 | 89 | 10 | 2 6 2 |-12
Stock solution-+ | yes ne oS Bat “ ea [82 1 fo 2 4% 4. 135
Stock shiek iS — ae ny a = 47 | 28 | To I 3 a4 57
667cc.KCl .375M
tiie: solution+ } 333 cc. CaCl, 375 M| 73 | 2% | 2° I 3 t 1:2
grocer. RCI - 395 M
ea solution+ ee tec. CaCl .375M 66 | 28 6 Bee ‘ 8
1. It }- th 4 + dAic tinned
Piants were alive
* a . * «tL
The (+) sig tes that t
* It should be noted that th bank 1 in a NTACl
nation has been found which is decidedly better than those given
in the table.
Similar results were obtained with hs cadet Ptilota, Tridaea,
and Prionitis.
Very much more striking results were obtained when experi-
ments on regeneration were made in these solutions. Pieces of
1912] OSTERHOUT—PLANTS AND SODIUM 535
Ulva were cut into strips and placed in the solutions. In sea water
_ and in artificial sea water the cells along the cut edges grew and
divided repeatedly, but this did not occur in any of the solutions
which lacked sodium (figs. 1 and 2).
In view of these results we may conclude that for the plants
studied sodium is as necessary as for animals. That its function
is not merely to maintain osmotic pressure is evident from the fact
that if sodium chloride be replaced by an osmotically equivalent
amount of cane sugar the plants quickly die. That sodium is
Fics. 1 and 2.—Fig. 1, portion of a frond of Ulva cut along one edge for experi-
ments on regeneration; fig. 2, regeneration along the cut edge of a frond of Ulva; the
newly formed cells are dotted; this regeneration takes place only in solutions contain-
ing sodium
needed to antagonize the toxic action of the other salts in the solu-
tion is clear from these and previous experiments.?, Whether sodium
is needed for nutrient purposes must be decided by further experi-
ments.
Since this investigation was begun, papers by RicHTER’ have
appeared in which he states that sodium is necessary for the nutri-
tion of certain marine diatoms but not for that of other marine
algae. Aside from diatoms his experiments seem to have been
confined to a single unicellular alga. Many unicellular forms are ©
so exceptional in their behavior that it would be unwise to draw
general conclusions from experiments conducted on them alone.
RICHTER states that while they grow in the absence of NaCl, they
? OsTERHOUT, Bor. Gaz. 42:127. 1906.
3 RicutTer, Sitzungsb. Kais, Akad. Wien 11821337. 1909. —
536 BOTANICAL GAZETTE [DECEMBER
grow much better when it is present. In his experiments only
Na, K, Mg, and Ca were used, and the proportions employed were
not those which exist in sea water.
Summary
Sodium is as necessary for the marine plants studied as for
animals; its replacement in sea water by NH,, Ca, Mg, K, Ba, Sr,
Cs, Rb, or Li is decidedly injurious.
The best substitutes for Na are the other kations which pre-
dominate in the sea water, Mg, Ca, and K.
The behavior of various species toward certain salts indicates
that each of these salts has a specific action on life processes.
LABORATORY OF PLANT PHYSIOLOGY
HaArvARD UNIVERSITY
BRIEFER ARTICLES
THE PERFECT STAGE OF THE ASCOCHYTA ON
THE HAIRY VETCH
It is quite well known that species of the form-genus Ascochyta
produce a disease of the vetch, pea, and other leguminous plants. In
the autumn of 1908 I collected a number of affected pods of the hairy
vetch (Vicia villosa) which was growing on the farm of Cornell Uni-
versity. These were placed in a wire cage and partly covered by
some leaves and grass used as a mulch for Rhododendron maximum in
my garden. It was hoped that the perfect stage might be obtained.
During early May in 1909 the cage was taken to the laboratory, and
a few pods were found on which there were a number of perithecia
which proved to belong to the genus Sphaerella (Mycosphaerella),
although pycnidia of the Ascochyta were present on the same pods.
hey were at some distance from the perithecia, and by using care it
was not a difficult matter to obtain an abundance of ascospores for
making pure cultures in bean pod agar, and also for inoculation of
vetch seedlings.
The germination of the ascospores was studied and the growth of
the colonies was observed up to the formation of pycnidia and pycno-
spores identical with those formed on the vetch pods, evidence that this
Sphaerella was the perfect stage of the Ascochyta of the vetch. Inocula-
tions of vetch seedlings were made with pycnospores obtained in pure
culture from sowings of ascospores. These were somewhat slow in
taking, but on May 18 a few brown spots appeared on the stems, and on
May 24 some of the leaves were dead and pycnidia of the Ascochyta
were present.
On May 13 ascospores taken directly from the pods of the vetch
were sown on vetch seedlings. On May 17 brownish depressed spots
were present on the stems. By May 18 these spots had encircled the
stem and the terminal shoot was thus killed. Again on May 15 asco-
spores were placed on young vetch seedlings. On May 18 a few of the
leaves were dead and pycnidia were present. By May 22 the disease
had spread somewhat and more pycnidia of the Ascochyta were formed.
On May 15 pea seedlings about 10 cm. high were inoculated with asco-
537] | [Botanical Gazette, vol. 54
538 BOTANICAL GAZETTE [DECEMBER
spores from the vetch pods. By May 18 the edges of some of the leaves
were dead and a few pycnidia of Ascochyta were formed. In all of these
cases check host plants remained free from the disease.
The ascospores are shot out from the asci on the absorption of water.
This was observed in a number of cases. While this is given as the
characteristic method of escape of spores in the family Mycosphaerel-
laceae, the behavior of the asci and spores is not the same in all species.
In this Sphaerella the outer, firm layer of the ascus wall is ruptured
or dissolved at the apex, and the inner, thin layer then stretches out
to three or four times the length of the mature ascus. When the spores
are shot out through the end of this inner membrane, either successively
or in a group, the inner membrane, which is very thin, collapses, while
the outer layer of the wall, which does not stretch, usually remains
Ascochyta occurs, usually in abundance, on the vetch, pea, and
Melilotus in the vicinity of Ithaca. For the purpose of comparing the
species on these different hosts, studying the life history and interrela-
tionships on the different hosts, this problem was assigned in 1910 to
Mr. R. E. STONE, a graduate assistant in the department of botany.
This work is now completed and will shortly be published in the
Annales Mycologici.—Grorce F. Atkinson, Cornell University, Ithaca,
‘ee
GAUTIERIA IN THE EASTERN UNITED STATES
For many years before seeing a specimen of the genus Gautieria I
had longed to find one, since it occupies a rather unique position in
the Gasteromycetes, because it is the only representative of the group
in which a peridium is wanting. From the literature and illustrations
I had a fairly good concept of it, and each year wished that I might
have a specimen to exhibit to my classes, because it offers such an excel-
lent demonstration of the gleba of a gasteromycete without sectioning
or removing the peridium.
On October 30, 1905, Dr. A. A. ALLEN, recently an assistant in the
department of zoology at Cornell University, who was then a Freshman,
brought into my laboratory a small plant about the size of a marble
which I at once recognized as Gautieria. He had collected it the previous
day while on a stroll through the woods on South Hill about three miles
distant from the university. Seeing an old, half-decayed specimen of
Ganoderma applanatum lying on the ground, where it had fallen from
IgI2] BRIEFER ARTICLES 539
the trunk of a dead tree, he kicked it over and the specimen of Gautieria
rolled out from beneath.
A few days later I organized a party of advanced students for an
excursion to the locality. In the leaf mold near the dead tree we found
some half-dozen other specimens. Specimens have again been found
during the past summer by Mr. H. H. Fitzpatrick, one of my graduate
students, who has just completed a study of its development, since he
found it in all stages of growth.
Gautieria morchelliformis Vitt., of Europe, has been reported from
Mexico. G. monticola Harkness has been described from California.
The species collected in the vicinity of Ithaca I have regarded as Gautieria
graveolens Vitt., of Europe. It has a strong, peculiar, and unpleasant
odor which is characteristic of several closely related species.
The plant is attached at the base to a slender whitish rhizomorph
which broadens out within the gleba in the form of anastomosing planes
forming the sterile avenues which are covered with the hymenium.
These make up the gleba tissue, or walls, which separate the winding
chambers which open to the outside. The spores are beautifully
sculptured, being longitudinally or obliquely ribbed.—GrorcE F.
ATKINSON, Cornell University, Ithaca; N.Y.
‘CURRENT LITERATURE
MINOR NOTICES
Nathanson’s textbook of botany.—This book? is written from a strictly
physiological standpoint, structures receiving scant attention except as they
e related to functions. The subject-matter is divided into two parts, the
vegetative life and the reproduction. The first part is subdivided into (1)
nutrition as a fundamental function of vegetative life, (2) the vegetative
organs of the algae, (3) the structural plan of the organs of the higher plants,
(4) the life history of the vegetative organs of the higher plants, (5) the orienta-
tion of the vegetative organs in space, and (6) the structure of the vegetative
organs under special conditions of nutrition. The second part is subdivided
into (1) reproduction in the lower plants, (2) mosses and cryptogams, (3)
reproduction in flowering plants, (4) the relation between the vegetative life
and reproduction, and (5) heredity. The book closes with a few remarks on
the principal groups of plants.
This presentation could be read, with profit, by all classes of botanists,
particularly by morphologists, who stand in greater need of such a presentation.
Morphologists, however, can hardly regard the text as a “general botany,”
since it gives so little attention to development and phylogeny.—CHARLES
J. CHAMBERLAIN.
Natal plants.*—The recent appearance of part 4 completes the sixth
volume of this well known work. The present part contains descriptions and
full-page illustrations of 25 species, most of which are of comparatively recent
publication, hence little known. A brief chapter is added giving notes and
corrections on plants mentioned in volumes I-VI inclusive. One species,
Brachystelma Franksiae N. E. Brown, is new to science.—J. M. GREENMAN.
NOTES FOR STUDENTS
Physiology of lichens.—The greatest advantage to the lichen of parasitism
with the alga was formerly supposed to be that the lichen received carbon
which the alga obtained from the air. But now it appears reasonable to suppose
that the lichen may furnish the alga a portion of the carbohydrates which it
secures from the substratum. This of course cannot occur when the lichen
« NATHANSON, A., Allgemeine Botanik. 8vo. pp. vili+-471. Jigs. 394. Leipzig:
Quelle und Meyer. 1912. °.
2 Woop, J. Meptey, Natal Plants. Vol. 6, p. 4, pls. 576-6oo. Bennett &
Davis. Durban, 1912.
540
1912] CURRENT LITERATURE 541
grows on rocks that contain no organic matter. Breathing pores have been
postulated for the lichens in a general way, but we really know little about
provision for exchange of gases in these plants. The student will find a general
summary by Finrsttck in ENGLER and PRANTL’s Natiirlichen Pflanzen-
familien. In 1906 Zorp3 described a new Ramalina (R. kullensis) which has
the so-caJled breathing pores well developed, and ROSENDAHL‘ in 1907 found
them.in Parmelia aspidota. Nothing more seems to have been added to
Finrsttck’s statement, and it appears probable that sah from the
exterior to the interior of lichen thalli are rare instead of c
TosLers thinks that such passages may be ists in » thalli with thick
cortices, but scarcely in those with thin cortices, where sufficient aeration may
TOBLER cultivated Xanthoria parietina and a number of other lichens without
algae in a gelatin-beerwort medium and got a rich production of calcium
oxalate. He then cultivated the thalli with the algae and was not able to find
the oxalate. He supposes, therefore, that the algae used the surplus extracted
from the medium by the lichen, and that the same occurs in nature, the lichen
taking the oxalate from the organic substratum. We may add that according
to ELENKIN’s® theory of gre ais the lichen may extract organic
compounds from the dead algae for the li
3
plants. ‘It was found that these algae are able to thrive on artificial media
containing organic acids, and the conclusion was reached that they behave
much like fungi with respect to carbon assimilation.
TOoBLER failed to notice the excellent work of ARTARI,’ performed on algae
which grow in lichen thalli, to ascertain the physiological relationship of the
p, W., Biologische und oO ee iiber Flechten. II.
Ber. Puaay Bot. Gesells. 242574-580. pl. 2
4 ROSENDAHL, F., Vergleichende nee ese OS! iiber die braunen
Parmelien. Nov. Act. Kais. Leop. Karol. Akad. 87:404-459. pls. 25-28. 1907.
STopier, F., Zur Ernahrungsphysiologie der Flechten. Ber. Deutsch. Bot.
. 2923-12. IgII
6 Etenxin, A., Zur Frage der Theorie des Endosaprophytmus bei Flechten,
Bull. Soc. Imp. Nat. Moscou II. 18:164-186. 1904.
O., Organische Siuren als Kohlenstoffquelle bei Algen. Ber.
Deutsch. Bot. co 232432. 1905.
rTARI, A., Uber die Entwickelung der griinen Algen unter Ausschluss der
_ Bedingungen Am: Sik eidiere Assimilation. Bull. Soc. Imp. Nat. Moscou IL. 23:39-
47. figs. 2. 1899
542 BOTANICAL GAZETTE [DECEMBER
algae to the lichens. ARTARI grew Cystococcus humicola, obtained from the
thalli of Xanthoria parietina and Gasparrinia murorum, in pure cultures on
complicated media containing mineral salts or organic compounds, or in some
instances both the salts and the organic matter. He found that the algae grew
luxuriantly on the media containing organic matter and were dark green in color
when grown in absolute darkness or in light with CO, excluded. On media
containing mineral salts but no organic matter, the algae grew under similar
conditions, but not so well. These results square beautifully with those of
TosLer, the one worker giving special attention to the lichen, and the other
to the alga which lives in the thallus of the same lichen. The two researches
show conclusively that the alga which lives in the thallus of Xanthoria parietina
can obtain its organic matter as well as the mineral salts from the lichen, pro-
vided the latter grows on some other substratum than rocks that contain no
organic matter.
BEYERINCK, BOUILHAC, ETARD, KLEBs, and others have obtained results
with algae somewhat similar to those of TREBOUX and ARTARI, two of the
authors working on a blue-green alga (Nostoc). Trentepohlia umbrina grows
in the bark of trees, sometimes with lichen thalli and sometimes alone. In
fact this alga bores into the bark of trees or effects an entrance through minute
openings in the periderm, probably either because abundant light is not favor-
able to its best development, or because closer relationship with the organic
matter of the periderm is more essential to its development than bright light.
This alga would be an especially favorable object for such investigations as
those noted above.
ToBLER also started cultures of Xanthoria on gelatin and transferred them
to a liquid medium which contained none of the carbon compounds needed by
the alga except what was in the air, and the lichen grew somewhat. ‘The alga
grew in the same liquid medium and was of normal appearance. In trans-
ferring the lichen, particles of the gelatin were unavoidably carried over. After
these were probably consumed by the lichen, the alga was introduced into the
culture with the lichen and grew well, but was colorless. This, he thinks,
indicates that the lichen had assimilated the acid which the alga needed as a
source of carbon, probably oxalic acid. He says that gelatin is not a source
of carbon for the alga, so that his conclusions would not be invalidated even
if the lichen had not extracted all of the gelatin from the medium before the
alga was introduced.
The lichen hyphae soon entwine some of the algal cells in the culture, and
thus the parasitic, or at least a symbiotic, relationship is established. ToBLER
believes that the lichen obtains carbon from the alga, while the latter replaces
it by extracting carbon from the oxalic acid contained in the tissues of the
lichen. This means a mutual exchange of food materials between the lichen
and the alga, at least as a probability. His investigation seems to indicate
that the alga growing in Xanthoria parietina and those found in several other
lichens very probably obtain their carbon from the lichen, the latter in turn
1912] _CURRENT LITERATURE 543
obtaining it from the organic material in the substratum. This is probably
true except for lichens that grow in substrata containing no organic material
and perhaps for those having thin cortices. ROSENDAHL found that thinness
of cortex and presence of calcium oxalate go together in the species of Parmelia
studied. This would indicate that the algae in lichens with thin cortices
obtain their carbon from the air, and so the oxalate is stored in the lichen,
while in the lichens with thick cortices the alga secures little or no carbon from
the air and utilizes the oxalate obtained from the substratum by the lichen.
These investigations of TOBLER, ARTARI, and others prove that we know
little regarding the nutrition of lichens and their algal hosts. The results
already obtained are important and suggestive. . is to be hoped that much
more work of this kind may be done.—Bruce FIN
Metabolism of fats.—IvANow has published a series of papers on the
metabolism of fats in higher plants. He emphasizes how little our knowledge
has advanced in this field since the classical work of Sacus, and contrasts it
with the advances made in our knowledge of protein metabolism in plants.
IvANow? believes he has established that the synthesis of fats from glycerin
and fatty acids comes about through the nies action of lipase, a view
apparently well established in animal meta
other paper” deals with the isueabgresbnd of fats during germination.
In order to have seeds with the greatest possible variation in the nature of the
fats as regards the saturation of the fatty acids involved, he used flax (ve
rich in fatty acids of the linoleic type: CaHzn—60z), hemp (rich in the linoleic
type: CaH2n—,O2), rape (rich in the oleic type: CaHzn—20.), and poppy (rich
in the palmitic type: CnHznO2). In the developing seedling he finds that
the intensity of consumption of the fatty acids originating from the fats is
inversely proportional to the degree of saturation. The linoleic type of acid
disappears first, and with it of course the hexabromide test; then follows the
linoleic, oleic, and finally the palmitic types. The fall in the iodine number of
the fat during germination is due to the more rapid transformation of the
more unsaturated acids to carbohydrates, and not to their saturation by
oxidation leading to the formation of acids with shorter chains. e aci
number of the fat from each plant is a strictly determined matter, low when
the fats are rich in unsaturated acids, and high when rich in saturated acids.
If the constituent parts of the oil in a plant are known, one can approximate
closely the acid number of that oil. The unsaturated fatty acids are largely
tied up in the glyceride, while the saturated acids exist to a larger degree in
the free state. The transformation of the oils during germination is by
9 Ivanow, Sercrus, Uber Oelsynthese unter Vermittlung der pflanzlichen Lipase.
Ber. Deutsch. Bot. Gesells. 29: 595-602. fig. I. IQ1I.
, Uber die Verwandlung des Oels in der Pflanze. Jahrb. Wiss. Bot.
50: 375-386. ae
To
544 BOTANICAL GAZETTE [DECEMBER
oxidation to carbohydrates, but the intermediate products are not known and |
are the next substances for investigation. Since the unsaturated fatty acids
are so readily oxidized to carbohydrates (an exothermic process) during
germination, the author concludes that their appearance in a plant is a special
adaptation, making rapid germination possible by a great liberation of energy.
As long as we know so little about the phsyiological use, if any, made of most
of the energy liberated by such oxidations, this conclusion is without evidence
in its favor.
A third paper™ deals with the synthesis of fats in oily seeds. In the flax,
rape, etc., the testa is formed first, followed by the development of the embryo.
Pentosans accumulate early, having their only réle in the formation of protect-
ive structures in the testa and playing no part in nutrition. The carbohy-
drates (glucose, cane sugar, and starch) are the main substances from which
fats are synthesized; while the proteins play a minor if any part in the process.
Of the carbohydrates, glucose is first used, followed by the hydrolysis and use
of cane sugar, and y starch. Intense oil formation occupies about two
weeks in the middle of the seed development period. Up to the time of the
beginning of oil formation, carbohydrates are stored in the stem. At this time
the hydrolysis of the carbohydrates in the stem begins, and, due to their
transformation to insoluble materials, oils, etc., in the seed, a falling gradient
is established in that direction, causing the diffusion to the developing embryo.
The first acids formed are saturated, as shown by the iodine number. The
author also believes that they belong to the higher members of their respective
series, for the Reichert-Meissel number is constant, and it does not vary with
the acid number. | It is also concluded that the volatile acids play no part in
fat synthesis. The acid number varies greatly in the oil from various plants,
being very low in oils from seeds rich in unsaturated acids. The author believes
the following scheme shows the main features of oil synthesis in a form like
the flax seed
glycerine
glucose ;
(cbohyeateer Dail
saturated fatty acids——unsaturated acids
The variation in the iodine number with stages of development is the
greater the greater the proportion of the unsaturated acids in the oil. In
seeds with few fatty acid components in their oils (rape and hemp) the
variation in the physical and chemical characters of the oil with stages of de-
velopment is slight; while in seeds with oils of many fatty acid constituents
(flax and poppy) these variations are great.
It must be remembered that such quantitative analyses cannot certainly
determine the series of products and reactions involved in a synthesis, for many
™Tyanow, SERcius, Uber den Stoffwechsel beim Reifen dlhaltiger Samen mit
besonderer Beriicksichtigung der oe Beih. Bot. Centralbl. 28:
159-191. IQI2.
1912] CURRENT LITERATURE 545
of the intermediate products may exist in such small quantities as to escape
detection.—WILLIAM CROCKER
Endogone.—A paper by Bucuottz™ on the subterranean genus Endogone
presents an unusually important addition to our knowledge of the group
Hemiasci, established by BrEFELD to include supposed transitional forms
between the Phycomycetes and Ascomycetes. Further study of the forms
which were originally placed in the Hemiasci has resulted in the gradual
dismemberment of that group until it has lost its taxonomic status. As a result
of the work of BucHottz on Endogone, that form also must be removed from
the Hemiasci and classed with the Phycomycetes. Bucuortz includes in his
account 7 of the 17 species of Endogone (including one described as new in his
paper). Two of these, £. lactiflua Berk. and E. Ludwigii Bucholtz, have a
beau process resembling that of the Phycomycetes; FE. macrocarpa Tul.
and E£. microcarpa Tul. produce only chlamydospores; in E. pisiformis Link.
the zygospores or chlamydospores of the other forms are represented by
sporangia whose contents break up into spores as in the mucors; and in the
remaining forms studied, Z. lignicola Pat. and E. fulva (Berk.), the mode of
reproduction is not norears In these either sporangia or thin-walled nee
dospores are produc
The youngest seait bodies of Endogone lactiflua examined consist of a tissue
of interwoven hyphae covered by an outer more firmly interwoven layer,
forming a sort of peridium. Foreign hyphae occasionally penetrate the fruit
body, but these are easily distinguished from hyphae of Endogone by their
straight course and parallel walls. The hyphae of Endogone are sinuous in
their course and have many irregular inflations. Male and female gametangia
the other gamete, but no fusion of nuclei takes place. At the apex of the
fusion cell, now containing both nuclei, a portion of the wall is gelatinized, and
at this point a papillate outgrowth appears, which gradually enlarges as the
protoplasm. and nuclei pass into it from the fusion cell. This outgrowth
™ BucHOLTz, F., meer zur Kenntnis der Gattung Endogone Link. Beih. Bot.
Centralbl. 29: 147-225. pls. 8. 1912. Originally published in Russian: Neue Beitr.
zur Morph. und Cytologie der unterirdischen Pilze. T. I. Die Gattung Endogone
aus d. Nat.-Hist. Museum d. Grifin K. Scheremetjeff in Michailowskoje. Moskau
9:1911. See also preliminary note: Uber die Ie ge von Endogone lactiflua
Berk. Ann. Myc. 92329-3309. 1911.
46 ’ BOTANICAL GAZETTE [DECEMBER
3 \
enlarges and forms the zygote or zygospore. The zygospore becomes sur-
rounded by a thick wall showing differentiation into several layers. In its
completed state it is inclosed in a network of hyphae whose walls fuse and
become greatly thickened, forming, in cross-section, a sort of a corona around
the zygospore. The nuclei were not observed to fuse in the zygospore of this
species, but in Endogone Ludwigii a single large nucleus, supposed to be a fusion
nucleus, was observed in some of the zygospores. This process of zygospore
formation was observed only in the two species mentioned. In the other
species the fruit body is filled with asexually formed chlamydospores or with
sporangia in place of zygospores.
In his discussion the author points out the close resemblance between the
sexual reproduction of Endogone and the mucors on the one hand, and on the
other hand certain homologies between Endogone and the Ascomycetes. Thus
in the peculiar outgrowth of the fusion cell and the paired nuclei, he sees a
homologue of the ascogenous hyphae of the Ascomycetes, in some of which (as
_ , CLAUSSEN has shown for Pyronema confluens) the male and female nuclei do not
fuse, but remain in pairs until the formation of the ascus.—H. HASSELBRING.
Position of Gnetales.—In 1911 LicnrerR and Tison published a brief
statement of their view that Gnetales are apetalous angiosperms, a statement
that was noted and commented upon in this journal.3 Now they have begun
the publication of an extended argument for their position, the first part
dealing with Welwitschia.4 A very full résumé of the literature prepares the
way for a consideration of all the kinds of testimony available. The conclu-
sions reached cannot be attacked on the basis of insufficient knowledge of the
facts at hand, but of course they rest upon personal judgment as to the relative
gg vib! f the testimony, as do all conclusions in reference to phylogeny.
eneral contention in reference to Welwitschia is that the two kinds
of strobili Serie eRe have identical organization; that in the axil of
each bract there occurs a flower of the angiosperm type, comprising five cycles
of members; that the two innermost cycles form a tetracarpellary closed ovary
prolon d into a long style; that the functionally monosporangiate flowers are
derived from more primitive bisporangiate flowers; that Welwitschia
has retathed a large number of gymnosperm characters, especially in its
nd histology”; that in evolution such recondite characters change
and therefore the phylogenetic position is to be determined by
the floral Races, which are essentially angiospermous; that the great
reduction of flowers and their aggregation into inflorescences do not suggest
angiosperms in general, but rather a very specialized lateral phylum; that the
method of specialization resembles that of the Amentales, and therefore Wel-
13 Bot. GAZ, 51:479. Igii.
4 LicNnieR, O., et Tison, A., Les Gnétales, leurs fleurs et leur position systé-
matique. Ann. Sci. Nat. Bot. IX. 16:55-185. jigs. go. 1912.
1912] CURRENT LITERATURE : 547
witschia and Amentales belong to the same lateral phylum, the former at its
with gymnosperms and on the other with angiosperms one may obtain a rough
reconstruction of the characters of proangiosperms.
crux of this whole argument is the interpretation given to the inner,
micropyle-forming integument as of carpellary nature. If this is true, no other
testimony is needed; and if it is not true, then no other testimony can show
the angiosperm level. As stated in the former notice, this contention in the
main brings us back to the old conflict over gymnospermy. It is clear that
unless proangiosperms may have retained archegonia in stages of elimination.
It will be interesting to note the disposition made of Gnetum and especially
of Ephedra in the subsequent papers.—J. M. C.
Investigations on Coprinus.—WEiR® reports a series of miscellaneous
investigations on various species of Coprinus. He finds that the deliquescence
of these forms is brought about by the action of hae enzymes and ee on
entirely without the aid of bacteria. The
when the fruit bodies approach maturity. The various parts of the fungus
show considerable differences in resistance to the action of these enzymes.
None of the young tissues are affected by extracts of older individuals. Parts
of the gills and pileus of older plants, however, are readily dissolved, while
the stems are not much affected. er enzymes whose presence was shown
by appropriate methods are tyrosinase, peroxidase, catalase, emulsin, amidase,
differentiation of the regenerating tissues. It is found that in the very young
fruit body the power of regeneration is not localized, but that all parts are
capable of producing new plants from all cut surfaces. In the young cut stem,
pilei grow out most readily from the pith, but later, when the pith has dis-
appeared, the regenerating zone moves outward toward the periphery. In the
pileus, regeneration takes place most readily at first in the region which is to
become the hymenium, and later in the trama. The cuticle is not capable of
regeneration. Plants whose pilei were imbedded in plaster or stems whose
upper parts were thus imbedded, after removal of the pilei, produced new
outgrowths along the lower part of the stems. Attempts at grafting parts of
fungi on other individuals of the same species succeeded easily and gave
1s WEIR, ee R., ep vencerae iiber die Gattung Coprinus. Flora 103:
263-320. figs. 25.
548 BOTANICAL GAZETTE [DECEMBER
interesting results. All parts of Coprinus and other fungi exhibit distinct
polarity, so that when parts of stems or pilei are grafted in their normal position
on the corresponding parts of other individuals used as stocks, union readily
takes place by anastamosing of the hyphae. When the part used as the scion
is inserted in the reverse position, no union takes place. In partly resupinate
forms, like Polystictus, polarity was exhibited in the same sense, but portions
near the margins showed polarity to a less degree than the older parts.—H.
HASSELBRING.
Lagenostoma.—This paleozoic type of seed, the first to be connected
with Cycadofilicales, has been investigated further by Miss PRANKERD™ from
preparations of L. ovoides. The Lagenostoma type of seed has peculiarities that
are hard to relate to the structures of the more modern gymnosperm seeds,
and any additional knowledge of the factsis welcome. The structures revealed
by these new apapnce sel are described in detail, and some interesting
“theoretical suggestions” are made. The seed investigated strengthens the
suggestion of OLIVER and Scorrt that the outer fleshy layer of the cycadean
testa represents the cupule of Lagenostoma, the stony layer being developed
after fusion of the Lagenostoma integument with the cupule. The method of
pollination is discussed also, and the curious supposition that extraneous water
must be brought to the pollen chamber for the swimming sperms is continued.
The facts in reference to the peculiar ‘‘crevice-like” pollen chamber are
somewhat cleared up. It is shown that the contact of the “central cone”
with the outer layer of the nucellus is quite variable, so that apparent con-
tinuity might be developed in a variety of ways. The point of this is that a
preparation showing a space below and continuity aboves does not prove
necessarily that the pollen chamber is being formed from below upward. In
certain specimens this very appearance was observed and yet there were pollen
grains in the chamber. It is not even certain that the crevice-like chamber was
continuous around the central cone. The specialized apical portion of the
nucellus is called the ‘ ‘lagenostome,” and the suggestion as to its morphology
is very interesting. ss PRANKERD sees in it a modified apical annulus,
which in the fossil Seftenbergia is a multiseriate structure, but which in living
forms has become simpler. If this be true, we have a fern connection for the
structure that seemed to be hopelessly advanced, namely the seed.—J. M. C.
The foliar ray of dicotyledons.—Batrey” has followed up his previous
work on the rays of certain groups by a more comprehensive study of the
dicotyledons, resulting in some important conclusions. The primitive angio-
NKERD, THEODORA L., On the structure of the paleozoic seed Lagenostoma
ovoides sia Jour. Linn. Soc. London 40:461-490. pls. 22-24. figs. 3. 1912.
17 BAILEY, Invinc W., The evolutionary history of the foliar ray in the wood
of the dicotyledons, and its phylogenetic significance. Ann. Botany 26:647-661.
pls. 62, 63. 1912.
1912] CURRENT LITERATURE 549
sperms, possessing a siphonostele with strong development of secondary wood,
had uniseriate or linear rays, such as characterize the conifers. During the
warmer climate of the Mesozoic, ‘“‘sheets of storage tissue were built up from
congeries of uniseriate rays about the persistent leaf traces of evergreen
angiosperms. This primitive type of foliar ray has persisted in certain
species of primitive families (Casuarinaceae, Fagales, etc.). Later changes in
‘climate modified the storage conditions, and in the majority of living dicoty-
ledons the aggregated units of foliar ray tissue have been diffused through
the stem, and in general the evidence of their former relation to leaf traces has
eure red. In a small number of forms the primitive aggregate type has
been “progressively compounded or solidified,’ and’ the result is the con-
pound or multiseriate ray (deciduous oaks, etc.). In many families there
has been a reversion to the primitive uniseriate condition. As a consequence,
in the modern species the foliar ray of the primitive aggregate type has been or
interesting and important in any scheme of classification. For example,
Castanea and Castanopsis are reduced members of the oak family, and Alnus
mollis and A. acuminata are reduced species of Alnus.
It is increasingly evident that the woody cylinder of angiosperms is very
far from being a structure of phylogenetic simplicity.—J. M. C.
Bog vegetation.—In studying the various problems connected with the
peat bogs of Ohio, DacHNowskI® has made a careful enumeration of the various
plant associations involved, and traced the variously modified successions’
which occur. Fortunately he has not been content with observations, but
has attempted various lines of quantitative study of the factors involved, such
as the height and variation of the water table, the acidity of the soil, and the
evaporating power of the air. He has also begun a series of chemical analyses
of bog water and peat soils. The preliminary results are valuable as being
suggestive of lines for future investigation rather than as affording solutions
f
position products of proteids and maltese that are now beginning to be
isolated and identified —Gro. D. FULLE
8 DACHNOWSKI, A., bs succession of vegetation in Ohio lakes and peat deposits.
Plant World 15: 25-39.
199. The pemet . Ohio = vegetation to the chemical nature of peat soils.
Bull. Torr. Bot. Club 39:53-62. 1912
550 BOTANICAL GAZETTE [DECEMBER
Germination of teleutospores.—In order to throw some light on the
parallelism between the time period during which teleutospores are capable of
germination and that during which their host plants can be infected, DreTEL””
has, in a general way, studied some of the factors influencing the germination
of teleutospores of Melampsora. Early in March the teleutospores of Melamp-
sora Larici-Caprearum Kleb. germinate in about three days when brought into
a higher temperature. The time required for germination decreases as the
season progresses. Whether the shortening of the period required for germina-
tion was due to temperature changes or to a kind of after-ripening of the spores
independent of the temperature was not determined. Temporary dryin
stened germination. “Temporary freezing did not retard the process. Strong
light delayed germination. Germination takes place at temperatures as low
as 6° C., and only in the neighborhood of this low point was any influence of
temperature observed. Experiments with M. Tremulae seemed to indicate
that germination in this form is less influenced by drying than in M. Larici-
Caprearum. Germination takes place at temperatures of 6°—-10° C., but pro-
ceeds more rapidly at 15°—-20° C_—H. HAssELBRING.
Seedling structure in Leguminosae.—Compron has made a notable con-
tribution to our knowledge of seedling structure. He has examined 201 species
of Leguminosae, ranging through all the regions of that vast family. The
three parts of the paper present the detailed descriptions, the summarized
information, and the general discussion. Under the last head the following
topics are considered: the nature of the hypocotyl, hypogeal and epigeal
germination, the epicotyl in the Vicieae, the level of the transition, the level
2 transition and the mature habit, the level of transition and phylogeny, the
ype of symmetry, plumular traces in hypocotyl and root, tetrarchy, reduction
al the number of protoxylems, triarchy, other types of symmetry, the relation-
ships of the types of symmetry, the size of the seedling, the primitive habit.
It is obvious that in so extensive a work no outline of the results can be given,
and we commend those interested to the 14 conclusions stated by the author.
The closing sentence is significant: “To a limited extent, therefore, characters
of seedling structure may be of diagnostic value; but it is porated risky to
apply them to solve the broader problems of phylogeny.” —J. M
Effect of tarred roads on vegetation.—With the extension of the use
of gas-tar, petroleum, and bituminous substances for surfacing roads, especially
in public parks, the question of injury to plants by these substances becomes
one of importance. While many experiments have shown that plants are
easily damaged by the fumes of tar and similar substances, such experiments
DreTet, P., Versuche iiber die oe der Teleutosporen einiger
Uredineen. Centralbl. Bakt. II. 31:95~-106. 19
2t ComPTON, R. H., An investigation of the sexing structure in the Leguminosae.
Linn. Soc. Jour. Bot. 4121-122. pls. 1-9. 1912
1912] CURRENT LITERATURE 551
have as a rule been conducted from a laboratory standpoint, and have left
unanswered the question of the slow action of these substances under sea
conditions. From a study of the effects resulting to vegetation a e
tarred roads in some of the parks of Paris, GATIN? s that sascha oe
damage is done to trees and other plants by the ia dust particles;
accordingly the injury is less severe along the less frequented roads. A
peculiarity of the injury is that it develops very gradually, and in case of the
trees did not appear until the practice of surfacing the roads with tar had been
continued for two years. Dust collected from tarred roads and dusted at
- frequent intervals on nursery stock produced characteristic injury, consisting
of spotting and browning of the leaves and retardation of growth.—H.
HASSELBRING.
Cystidia as ahah i ana As a result of a critical examination of the
cystidia occurring in the hymenium and similar cystidia-like trichomes often
found distributed over other surfaces of the fruit bodies of Hymenomycetes,
they function exclusively as hydathodes. KwNo.t finds that the exudation of
water is restricted to a definite region, with few exceptions, situated at the
apex of the trichome. The cell wall at this point is capable of swelling to such
an extent that it forms a colloidal solution in the excreted water. That the
drops adhering to the ends of the hydathodes consist of a colloidal solution is
shown by the gelatinous residue left when the drops are allowed to evaporate
deposited on the ends of the hydathodes as a result of erapuretiol of the liquid.
—H. HASSELBRING.
Plant diseases of Texas.—A survey of the plant diseases occurring within
a radius of 100 miles of San Antonio, Texas, has been published by HEALD and
Wotr.% The paper is based on collections made by the writers during a period
of about two years, from 1908 to 1910. It comprises a list of fungi collected
on about 200 species of hosts within the region examined, together with brief
descriptions of the fungi and notes on the effects produced on the hosts. A
number of well executed plates accompany the text; however, the motive that
2 Gatin, C. L., Die gegen die Abnutzung und den Staub der Strassen angewen
deten past 9 — ihre Wirkung auf die Vegetation. Zeitschr. Pisreebkrank.
22:193-204. 1912.
23 KNOLL, F., Untersuchungen iiber den Bau und die Funktion der Cystidien und
verwandter Organe. Jahrb. Wiss. Bot. 50:453-sol. figs. 69. 1912.
24 Heap, F. D., and Wotr, F. A., A plant disease survey in the vicinity of San
Antonio, Texas. Bur. Plant Ind. Bull. 226. pp. 112. figs. 2. pis. 19. 1912.
552 BOTANICAL GAZETTE [DECEMBER
guided the writers in their selection of material for illustration is not clear.
As a list of parasitic fungi from a region where little systematic collection has
been carried on, this paper is a useful contribution. Its usefulness might have
been greatly enhanced if the authors had indicated what part of their material
constituted additions to the known fungus flora of Texas, and what part
represented species formerly known from that region, for it can scarcely be
oubted that so extensive a collection of material contains much that is new
to the region.—H. HASSELBRING.
A new type of Cycadofilicales.—From a study of numerous casts,
ScHUSTER*®’ has described the staminate and ovulate flowers of Schuetzia
anomala and has drawn some conclusions in regard to the position of the genus.
The impressions of the staminate flowers were so numerous that it was not
difficult to make reconstructions. The flower consists of 12~20 cyclic sporo-
phylls united throughout the lower two-thirds = ‘their length and bearing
sporangia upon their inner surfaces, resembling SELLARD’s Codonotheca and
Stur’s Calymmatotheca. 'The flowers are in a ‘penis inflorescence. The
longitudinally striated “seeds” described by GoEPPERT are regarded as mega-
sporophylls, and it is important to note that these megasporophylls are in
undoubted connection with twigs bearing conifer-like leaves. On account of
this association, SCHUSTER would make Schuetzia the type of a new group
of Cycadofilicales, characterized by the conifer-like leaves——CHARLES J
CHAMBERLAIN
Root nodules of Podocarpineae.—Miss Spratr® has found that root
nodules are present in Podocarpus, Microcachrys, Dacrydium, Saxegothaea, and
a ae being modified lateral roots. A root-hair is penetrated by
omonas radicicola (a nitrogen-fixing organism) and from thence enters
ne cortex. In all cases the nodules are produced by the infection of the
meristematic tissue of the young lateral root before it emerges from the cortex
of the parent root. Many interesting observations are made upon the stages
of the bacteria and also upon the condition of the tissues of the host. The
conclusion is suggested that the morphology of the nodules favors the view
that Podocarpus and Saxegothaea “are the most widely divergent of the genera
in the Podocarpineae, and that they are connected through Microcachrys and
Dacrydium.”” The presence of the nodules in Phyllocladus is also further con-
firmation that the genus is related to the podocarps rather than to the taxads.
At Ae
2s ScuusterR, J., Uber die Fruktification von Schuetzia anomala, Sitzungsb.
Kaiserl. Akad. Wiss. Wien 120:1125-1134. pls. 1
26 SprATT, ETHEL Roser, The formation a eeeetieai significance of root
nodules in the Podocarpineae. Ann. Botany 26:801-814. pls. 77-80. 1912.
1912] CURRENT LITERATURE 553
Morphology of Uvularia. —Miss ALDEN” has investigated the life history
of Uvularia sessilifolia, chiefly as to the sequence of events, presumably in the
region of New York City. The archesporium of the microsporangium (3-6
cells) becomes differentiated the first of August, at which time also the division
into parietal and sporogenous series occurs. Mature microspore mother cells
were found in the middle of September, and the tetrad divisions occurred in
October, so that the winter is passed with the microspores fully formed. In
the latter part of the following April the division of the microspore nucleus
into generative and tube nuclei occurs, and probably the former divides after
the shedding of pollen. The archesporium of the megasporangium is differen-
tiated early in March (seven months later than the microsporangiate arche-
porium), and consists of a single hypodermal cell which does not cut off a
parietal cell. The reduction division occurs the last week of April.—J. M. C.
Spermogonium and fertilization in Collema.—Miss BACHMANN® has
investigated Collema pulposum as to the nature of the spermatia and its bear-
ing on the question of functional sexuality among the Ascomycetes. The
spermatia of this species are not born in spermogonia, but few in number upon a
hypha below the surface of the thallus, being completely imbedded and never
set free. The carpogonia resemble those of other lichens in general structure,
but the long end cell of the trichogyne does not grow toward the surface of the
thallus, but more or less horizontally within the thallus toward the region of
the spermatia. The attraction of the spermatia for the trichogynes is shown
by the convergence of the latter about a group of spermatia. The spermatium
fuses with the trichogyne to which it has become attached, and the subsequent
changes are those that have been described. It seems evident that in this
case the spermatia and trichogyne are functional,—J. M M.C,
Seedling anatomy of Sympetalae.—Ler” has investigated the seedling
anatomy of Convolvulaceae, Polemoniaceae, Hydrophyllaceae, Boraginaceae,
Labiatae, Solanaceae, Scrophulariaceae, Bignoniaceae, and Acanthaceae. The
extent of the transition region is related in a general way to the size of the
seedlings, which varies greatly in different species. In the smaller se
the transition region is short, and the rearrangements are concluded in the
upper part of the hypocotyl; while in the larger seedlings the transition region
is very extended. Cotyledonary tubes occur in members of all the families,
77 ALDEN, ISABEL, A contribution to tHe life history of Usularia sessilifolia. Bull.
Torr. Bot. Club 39:439-446. pls. 34, 35. 1912.
28 BACHMANN, FREDA-M., A new type of spermogonium and fertilization in
Collema. Ann. Botany 26:747-760. pl. 69. 1912.
* LEE, E., Observations on the seedling eo of certain nics 1s
Tubiflorae. Ann. Botany 26:727-746. pl. 68.
554 BOTANICAL GAZETTE [DECEMBER
but their presence seems to have nothing to do with the transition phenomena.
The prevailing type of transition, present in all the smaller seedlings, is VAN
TIEGHEM’s type 3. Internal phloem was present in all the Solanaceae and
Convolvulaceae examined, with a few possible exceptions.—J. M. C
A disease of sugar cane.—The sugar plantations of Hawaii have suffered
greater loss from an endemic disease called “‘iliau”’ than from all other fungous
diseases combined. Lyon, now at the Experiment Station of the Hawaiian
Sugar Planters’ Association, has investigated the disease3° and finds that the
causal organism is a new species of Gnomonia (G. iliau), the imperfect stage
being Melanconium. The G nia form is infrequent, while the Melanconium
form is of constant occurrence. It is a leaf-sheath disease, and its attack
makes it a disease of young shoots only. The entrance is effected through the
leaf-bases inserted on the stem below the soil surface, and thence it extends
upward and inward. The tightly packed roll of leaf-sheaths surrounding the
young stem-tip is cemented into a rigid cone, so that it is impossible for the
stem-tip to escape.—J. M. C
Diaphragms in air passages.—Lr BLAnc* has reviewed the literature on
the diaphragms occurring in various aquatic plants and examined other species
in order to discover the origin, manner of development, and function of these
organs. One of the most peculiar features of these plates is the occurrence of
perforations in the form of peculiar intercellular spaces caused by the diminu-
tion of the cell contents and the consequent contraction of the cells. These
perforations permit free gas exchange and yet do not greatly detract from the
rigidity of the diaphragms. The diaphragms do not seem to be due to any
reaction toward the aquatic medium in which the plants develop, and appear to
e a portion of the mechanical tissue system occasionally containing some
reserve food materials —Gro. D. FULLER
Algae of Colorado.—Rosstns* has published a list of the algae of Colorado,
which brings together all the recorded species and the additions made by the
author during three years of investigation. The result is a list of 143 species,
including 38 Cyanophyceae and 105 Chlorophyceae. Spirogyra, with 14
species, is the largest genus.
e same authors has investigated also the occurrence of algae in certain
3° Lyon, H. L., Tliau, an endemic cane disease. Exper. Sta. (Hawaii) Bull.
II. pp. 32. figs. 10. pl. 1 (colored). 1912
31 LE BLanc, M., Sur les Haka des canaux aériféres des plantes. Rev.
Gén. Bot. 24: 233-243. 1912.
3? RosBINS, W. W., Preliminary list of the algae of Colorado. Univ. Colorado
Studies 9: 105-118. 1912.
———, Algae in some Colorado soils. Col. Agric. Exper. Sta. Bull. 184. pp-
24-36. pls. 4. 1912.
1912] CURRENT LITERATURE 555
-soils in which Azotobacter chroococcum 3 is extremely active in fixing nitrogen.
Nostocaceae. It is concluded that these algae are an important source of
energy for Azotobacter —J. M. C
Podozamites distans.—The fragments referred to this form, sometimes
under the name of Cycadocarpidium, have been regarded by some as pinnate
leaves, and by others as shoots with spirally arranged leaves. The mega-
sporophylls, with two ovules at the base, bearing some resemblance to those
of Dioon, are collected into a loose cone. Nevertheless, ScHUSTER*4 comes to
the conclusion that Podozamites distans is a primitive conifer, coming from the
same Cycadofilicales stock which gave rise to the Ginkgoales. Consequently,
he would have Podozamites removed from the Cycadales and placed with
Coniferales. ScHuSTER’s figures, as well as two of Natuorst’s which he
reproduces, seem to the reviewer to favor relationship to the Cycadales.—
CHARLES J. CHAMBERLAIN.
Anatomy of Equisetum.—Lady IsaBEL Browne* has investigated the
anatomy of the strobilus and of the fertile stem of Equisetum. The xylem
situation in this genus is of great interest, and in the axis of the strobilus it is
best developed. At the nodes, the xylem forms a ring or occurs as bands of
varying width; while in the internodes the xylem breaks up into definite
strands. E. arvense, E. palustre, and E. limosum form a series showing pro-
gressive reduction of the xylem. The study of the strobilus further confirms.
the view that the “‘sporangiophores” are not lobes of a suppressed foliar
member, but are “whole ee ee ” which would seem to indicate that they
are not sporangiophores.—J. M. C.
Stomata of Bennettites.—Licnier®* has discovered the existence of
stomata on the interseminal scales of Bennettites Morieri. The structure as
figured is obvious enough, and about the guard cells there are concentric
subsidiary cells. LiGNrer raises the question whether the presence of these
stomata does not indicate freedom for the movement of air among scales
and ovules, and therefore less compactness of structure than develops later,
when the seeds mature and the tips of the interseminal scales hypertrophy.
Since stomata occur within the ovaries of angiosperms, as Lilium for example,
their presence does not prove the free circulation of air.—J. M. C.
34 ScHUSTER, JULIUs, ee iiber ribo meeseace Ber. Deutsch. Bot.
Gesells. 29:450-456. pl. 17. 1911.
3s BROWNE, ISABEL M. P., Contributions to our knowledge of the anatomy of
* cone and fertile stem of Egquisetum. Ann. Botany 26:663-703. pls. 64, 65.
. 10. 1912
36 LiGNIER, O., Stomates des €cailles interséminales chez le Benneitites Moriert
(Sap. et. Mar.). Bull. Soc. Bot. France 59:425-428. figs. 2. 1912
556 BOTANICAL GAZETTE [DECEMBER
Classification of plants.—A third edition of Professor BEssEy’s Outlines
of plant phyla has appeared. The previous editions were noted in this journal
(51:317. I911; 53:275. 1912) and the general features of the classification
given. In the new edition the 14 phyla remain the same, but the families have
increased from 648 to 652. The relation of the conventional four great groups
- to this scheme may be indicated by the statement that the thallophytes are
broken up into 7 phyla, the bryophytes remain as a sina Sloe the pteri-
dophytes become 3 phyla, and the spermatophytes 3.—J. M
Perithecium of Polystigma.—BLAcKMAN and WELSFORD*’ have investi-
gated the development of the perithecium of Polystigma, and have discovered
that while well marked ascogonia occur, they disorganize without producing
ascogenous hyphae, and that the spermatia are also functionless. It differs
from most of the Ascomycetes in which the normal sexual process is absent
by the fact that both sex organs are distinctly produced, but that both are
abortive.—J. M. C.
Wound reactions in fern petioles.—Ho.pEn* induced wound reactions
in the petioles of 37 species of ferns, the wounds being thin superficial shavings
made with a scalpel in three regions: the curled apical portion, the region of
pinna insertion, and the region below pinna insertion. Various reactions were
obtained, which differ too much in details to be summarized in a review, but
all of which are interesting contributions to the subject of wound reactions.—
j. M. C.
Mycorhiza of Asarum.—Scuwartz* has studied the mycorhiza of Asarum
europaeum, finding it limited to the cortical region abutting on the steles of
young roots. Thick-walled swellings were found on some of the hyphae,
representing a resting stage.—J. M. C
Lateral archegonia in Pinus.—Saxton” has made the very interesting
discovery of a female gametophyte of Pinus maritima which bears two lateral
groups of two archegonia each, and no terminal (micropylar) archegonia at
all.—J. M. C.
37 BLACKMAN, V. H., and WELsForpD, E. J., The ae of the perithecium
of Polystigma rubrum D. C. Ann, Botany 26:761~767. pls. 7 12
38 HotpEN, H. S., Some wound reactions in filicinean settee hun: Botany
26:777-793. pls. 73, 74. fig. I. 1912.
_ 9 ScHwarTz, E. J., popeans on Asarum europaeum and its mycorhiza. Ann.
Botany 26:769-776. pl. 72. 19
4 Saxton, W. T., Note on an abnormal prothallus of soe maritima L. Ann.
Botany 26:943-045. fig. I. 1912.
GENERAL INDEX
Classified entries will be found under Contributors and Reviews.
New names
and names of new genera, species, and varieties are printed in bold face type; syno-
nyms in dalic.
A
Abrams, L. R., work of 168
Abutilon, microsporangia and micro-
ter pening - seeds of Crataegus 49
> > 2 a ae
ae
AGES
Pp
58
et:
a
ro. life history of Peasy 466
Alden, Isabel, work o:
Aleurone grains, artificial vplbdaction of
33
Algae of ager 5 554
Allen, C. E.,
ie
ectus oinochrophyllus “39 rua-
hilus 238; Soups rags S 238
\Inus i = siage anatomy of 2
\lsophila 3
ifeernations of preorrsas in Cutleria 482
\m
\mmophila arenatia anatomy of 269
\morphophallu 407
impelocera mts tl
\ndropogon scoparius, eens of -269;
> > 5 he Se A A Sn
ur us
Andropus carno
Pepe pinguis, life history of 177
— yphylla 236; tabascensis
hatheiLiis - Aneura 181
Anticlea 3
n Bryum 86
‘pple, ‘Chas. 0. 88
Aptian
Arable Nand impar 139
Araceae 427
ee. absorption of barium chloride
50
Ped E. A. Newell, work of 4
Archegonia, of Aneura 182; pee in
Pinus 556
Archilejeunea 34
Arctostaphylos T essutid anatomy of
Palen stricta, anatomy of 270
til
Artari, A., work of 541
aang canadensis 268; caudata,
anatomy of 268; potens 418
Ascochyta, perfect stage of 537
ss ii nudisiliquus
410; 0 S 411
Atkinso a. Geis: F. 537, 538
Australi plants 169
Azolla
achman, Freda M., work of 553
Bagniceieila 170
Bailey, Irving bite Mate : 548
Baker, E. C., work of 3.
Barium chloride, vrs a by Aragallus
°
Barnes, C. R., Coulter, J. eh —
H. C. “Textbook of bota:
440
ce in 250
Bennettites, stomata of 555
Bensley, 175
Benson, Margaret, work 0
rgen ip nd Caldv 0. WW,
“Practical botany’
of 440
Seaneonatlion, William, bre of 350
Birge, Willie I., work ae
Bischoff, Hans.
Black oaks 352
Blackman, V. H., work of 556
cork ore
557
558
Blastocladia, development of 353; stran-
gulata
<9 oon one nature of 89
Bletia, embryo ~~ of 377
Bliss "ais ary C., work of 88
rs: niente pr Rae and tolerance of
Bog vegetation 549
Boleta 170
Rarkneny, Th., work of 345
Botrychium, ebartives spike of 525
Rowenia 3 serrata 419; spectabilis serrata
419
Bower, F. Me work of 348
a saiah, «Forest physiography ”
ae i hain. stomata of 66
Britton, Ne A., work as 168
work of 8
el M. sae Work of 555
Bucholtz, r. work of
Butler, Ormond, work of 174
C
entula, anatomy of 26
-, work of 174
Carex 170
Case, Ca and Hall, H. M., “ Yose-
mite
Castilleja udtinatta : 148; viscida 148
Cecido 34; American
Celastrus scandens, anatomy of 289
Celtis occidentalis, anatomy of 277
etn es 34
Cen seal aarti nag Lape from 235
Goan rmae,
Cephalanthus coctieatals, anatomy of
Cephuloticnds 427
Chamberlain, Spore J. 68, 253, 410,
428, 540, 552, 5
Charnes, Grace M. 31
Chinese plants 170
Chiovenda, E., work of 169
Chondri es and chromatophores 175
Chromatophores an chon — mes I 175
Chromosomes of Cutleria
Cc vated ana nie is artus 4133
pumilus latus 4
INDEX TO VOLUME LIV
[DECEMBER
Chylisma scapoidea seorsa 140
Cicuta cinicola 151
Cirsium Pitcheri, anatomy of 268
ms app, oe om z77
k, J. F of 345
Saar as i ne 556
Coelogyne, embryo sac of 379
i work
ogniaux, A., of 169
Cogswellia
oe spermogonium and fertilization
C oe arent of 259
Color-facto s, Lychnis 120
Color- inhibition, Papaver 120
Colora ~ — of 554
Colum:
sabes, Hasal, work sat 88
om mpositae, fruit o of I
pton, R ork or 88, 264, 550
onceveiba + pleiostemona 243
onifers mata of Cretaceous 63
oniose om 346
onocybe 170
ontributors: ores n,C.O. 88; Atkin-
n, es Beri gee ne os 3533
Bensley Brown, SF
386; Chaniberiais: me J. 68, 253, 419,
428, 540, 552, 5553 Bier Grace M.
81; Clapp, Grace ak 77; Cook, M. T.
Te
BB
29999
$8:
Alfred 03; Dalgity, 164;
533, b twrcce, | Sophia H.
87; Fink, es 541; Fuller, G. D.
174, 254, 262, ;
Gager, C:. Si s1¢; G
258, 432, 437, 439, 449, 545, 55 we
Hitchcock, A. C. 423; Jones, W. R. 1
. o6;. Lantis,; V. 330;
Marsh, C. D. 2503 Metcalf; H. 173;
Nelson, A. 136, 167, 404; Osterhout,
We J. 532; Overton, 83;
Pace, Lula 306; Rigg, G. B. 164; Rose,
- 493 iataae ‘Ouwnla 31; Sharp,
; Shelford, V. E.
343
J. a ae
Wages ceke Shigéo 44
1912]
Cook, Mel. T. 340, 434
Cooper, dita S. 166
Copri
Corallohiza, oe sac of 376
Cor 176
Condvlanh bicoles 416
Cori m hyssopifolium, anatomy of
Cornus sto meg rene: anatomy of 285, 296
ort
26
-1 8 work of 43
Comleee ‘John ’M. 976, 87,88; 175, 254,
ae 349; 352) 428, 437, 438, 440, 546,
eo 346; ee of seeds
tennowana 4
tine, effect on gga ge 152
Creatinin Oa n growth 152
ree ie ong 19t, 265,435, 543;
Croton Tuerekheimii 242; verapazensis
242
Cryptanthe scoparia 144
Cryptostice lla 169
Cumarin, effect on growth and absorption
Bit influence of ee mde 245
Cutleria, alternation of generations in
4 2; ieee of 476; Tite history
ts
cates 256
Ceadoiicts, new type of 552
Cynomarathrum Macbridei 142
Cystidia as Reiathpiles Sex
D
Dachnowski, Alfred 503; work of 549
Dacrydium 255-
DeBruyker, C., work of 7
Deshi . the work of $8
eschampsia 34
Desert aawts, root habits of 174
Diacalpe
© 34
Dianthera flower of 21; seeds of 3;
Di
Dietel, P., work of 550
INDEX TO VOLUME LIV
559
Dignathia 347
Diplocarpon rosae 231
Hie otto my os
ipterostem 346
Dittschlag, E., work of 4
ear cats sanciceten niioaliniasels
as . , K., work of pb
Do bien ess, inheritance of 256
Draba lapilutea 1393 " jellowsianalitts 139
Dracontiodes 427
rosera, pears, aA ogy of 318
Dun e plants, simpatulivs anatomy of
e
5
Duthie, A. V., work of 255
E
Earlea 77
Eckerson, Sophia H. 87
aay 4 Ae “coe sil
Elmer je E.,
Embryo sac, doubling of a8: of Gunnera
437; of orchids
eny
Embryog of ‘Bannacuiceens 264
Paciie d 545
Engler, A., “‘Das Pflanzenreich” 427;
27
work o 169, 4
estate 169; embryo sac of 373
setum, eae of 555; spermato-
senbida ie
Erigeron 169; Biten meri 413; compositus
breviradiatus 416; filifolius Bloomeri
41 a aaa curvifolius #2; Sissuri-
oi
es gern of 431
Erfocaucanis
riogonum fascicalifo lium
Eston oganum 149; shcuhcsasts
Erlich, hee Piss of 342, 343
Esquirolia :
ugenia
Euphorbia satveoatetta: anatomy of
Euphorbiaceae 427
vaporation and stratification of vege-
424
F
Fagon
Fats, ‘metabolism of eg
Faul, . H., work of 8
169
ork of 349, 350
Fern petioles, eed reactions in 556
Fernald, M. L., work of 169
Ferns, new species 34
Fertilizer salts, and ois action of
organic compounds 3
560
ee recent work among 348
Fink, B T
Flax, inheritance - 35t
Flower, of Dian
Foliar ray of coeds 548
Forbe
» Gee Ns
Forenbacher, Aurel, ek “of 175
Shi es od am — 254
Fra ak, anatomy of 278
Frenelopsis,. anette of 63
Freycinetia 170
Fromher uy , work of 343
Frommia
Fruit of Compositas 176
Frullania a 34
174, 254, 262, 352, 424,
549, 554 :
Fungi, metabolism of 339
G
vomit CG. sagas _
Gan
Sarva S folia quichensis 237
Gas movements in see 35
Gates, Frank C., wo vss?
Gatin, C. L., work o
Gautieria in aster United States 538
Gazaland, flora
um I
Gnetales, position of 546
9
Greene, E. L., work of 16
songs , J. M. 77, 168, 346, 427, 420,
Grifiiths, D., work of 169
Griggs, Robert Ey aor
Gro . B., work of 169
rae studies in Pinus 386
Gummosis 17
Gunnera, embryo sac of 437
Gurania brachyodonta 237
Gutierrezia 170
Gymnosperms, recent work among 254
Gymnosporangium, biology and taxon-
omy of 258
H
Habenaria
Hackel, E., po of 169
INDEX TO VOLUME LIV
[DECEMBER .-
Hall, cent be M., as Case, Carlotta,
“Vos e flora’
fica: ieee, anatomy of 286
Hamelia 169
Hamilcoa 348
Hancock, Joseph L., “Nature sketches”
Harp Shes a work of 83
Ha aves L - 75
Hass acne . 84, 86,
439, 440, 545, 559, 551;
258, 432, 437,
work of 345
_ Hassler, E., work a 169
Hawaiian plants 16
Heald, a at work “of 551
Hebelom
A. re wale of 170
Hepaticae 34 347
tog, R. O., work of 340, 341
ioeead oa,
Heuchera, morphology of 318
a guatemalensis 241
of 170
f 435
Hudsonia tomentosa, anatomy of 271
Hume, E. M. Margaret, work of 349
Hydathodes, cystidia as 551
Hypericum Kalmianum, anatomy of 273
I
ee new plants from 1 36
U 554
Indiana, forestry in 2
Inheritance, in beets 2 Bea: in flax 351;
in wheat 260; in turnips 259; In
348
eg Sergi, work of 543
Ivesia 1
?
Jacobson, K. A., work of 342
17
Fee
g
ae
°
nal
~I
ro)
Joh
earn J: work of 76
Jones, W. Ralph 1
Jost, L., ork of 171,
Juglans | cinerea, Ble Ril of 279
9
ommunis, anatomy of 272;
virginiana, anatomy of 272
Kajanus, B., work of 259, a
Kennedy, P. B., work of 1
rn, F. D., work of Hf 170, 258
., work of 8
k of 342
anzlen, F., work of 170
Kuehn
Kiikenthal, G., work of 170
Kummerowia 34
L
POP IE. cytology of 84
Laciniaria 1
La.
mariti-
Leguminosae, seedlin alge in 550
ule Ee Lunellii tea 149
Léveillé,
Lewis ., work ie 7O
Lichens, ‘physio logy of 540
Lign fice BY a: of 546, 555
]
Sec trenta
Livkades deen anatomy of 2'
Lister, Ar thur and Sirti ““Myce-
tozoa’”’ 428
Lithospermum herrage anatomy of 270
Loeflingia verna 1
peal bead
Lopriorea
Lotsy, J. po keto 253
cus 4
S, primary c ibis Bic oick of 120
Ly pa sieve tubes of 340
ios n, H. L., work of 554
M.
Macb sad a; Be i of 170
aire, René, work whe 439
Maize, chemical graeme et: in 263
Makino, T., wor
Mallow rust 431
a ata ae 169
Marcha 1, E., work of 85
Mere lois ic
hs Dwight 250
INDEX TO VOLUME LIV
i mabe sieve tubes of 349
telli, U., work of 170 .
J bd
., work - 170
f
-~
a)
9
a
@
RS
iE
calf,
Mic eon tee of “Abution 330
] hea of Abuti se
istleto
straabemant 170
itrastemonaceae 170
er, W., work of 170
onardella 1
onimia 7
breed ea ed
F couoe eae
ycorhiza of Asarum 556
Myosurus, embryo of 264
N
ced
Hapa 168
Nash, George V., work of 429
Na aie A., “ Allgemeine Botanik”
Nature Sogpietiag 76
N
Ne Isia
Nelson’ Pha 136, 167, 404
Neocentema 346
Neokoeh 3
Neubauer, O., wo ork of 342,
New Mexico
plant geography ve 194
work of 260
North Soon Flora 77, 429
Notochloe
O
Oaks, black 352
Ohta, Kohshi, wor
of 3
Olpidiopsis, cytology <n Secuniie of 261
; Rafinesquii, anatomy of
271 :
Orchids 1703 ents sac of 372; new
cna 2a of 346
pou es toxic action of 31
work of 346
Osterhout, W. “532
Ostrya virginiana, anatomy of 281 -
Overton, J. B. 83
562
Pp
Pace, Lula 306
Paleobotanica notes 438
Palms
Pantan ali, E of
phd ‘olot inhibitors mt 120
Paradan 4
Pecactay, slants of 169
ris
. H. W., work of 255 .
Snape attenuatus 146; attenuatus
varians 146; brevis 417; confert
1453 eri pee Whitedii 148 ceaua
147; linarioides seorsus 147; procerus
146
Peranema 348
Pericyatie ave 440
Peridinium 3
Pe
shine wae of Polystigma 556
erkins 2 thongs work of 427
e rmeabilit 263
r, W., "ook of 171, 436
i lanzenrcich 427
celia firmomarginata 143
jus, phebia sac of 375
anerophle aie
nilippine pla
hlox lon Hola filicfolia 143
: eewiads 9
Phyllanthus — 241
Phytomyxacea
nus, Baltkaia i anatomy of 273;
in 556; rigida,
wt
Platanus occidentalis anatomy of 295
bai beige
Pluteo 70,
Poaceae
Podocarpese 2 254
Podoc oa map root nodules of 552
lateral a
86
Podocarpus
Podaaasiites pa 555
er embryo sac of 379
edz um 1 ls emaciatum 138
eae
Peo generation of ~
Polystigma, — um of 556
Polytrichu ae execs of 429
Populus, “balescnitecn, anatomy of 281;
deltoides, anatomy of 282
ctical y 75
isa: psig ea La; bp s 548
ns, work of
Pritchardiopsis 168
INDEX TO VOLUME LIV
[DECEMBER
rss ne anatomy of 271; virgini-
of 287
Panoshiis, oe of 81
Psedera quinqueolia, anatomy of 290
Pte
Pteridoca lyx
Puccinia Mates
Pyronema price Becta of 83
Quercus velutina, anatomy of 273
ae
Rankin, W. H., work of 346
Ranunculaceae, fags el of 264
Reichel, J., work of 345
Rendle, A. B., irl of 346
Respiration, cect of tpieatare 6
rgen and Caldwell’s
man’s ‘
EGO oe ter, et,
tbo any”
n 87
é Snip
‘Forest
ster’s ‘‘Mycetozoa
sy’s “Stammesgeschichte”
Beas athanson’s ‘Allg
tanik" 540} nT We “THlustriertes
—— cn” Wood’s “Natal
_ plants” 540
Rhus {oxcoendron, anatomy of 291
Rigg, Geor;
Rigiostachys quassiaefoia 23 ¢.
Ripke, O., — of 340, 341
Ritter, a. work of
ae Terman von Guttenberg, work
of I
Robbins, W. W., work of 554
Rust, mallow 43
Rydberg, P. A., work of 346
Sabulia
Saito, x a of 345
1912]
Sal adin, O., work o
175
Salix he boiseana 406; glaucophylla,
of 296; longifolia, anatomy
oe via gyrtiools, anatomy of 271
: sacar J. A., work o Ls
Sarg t © S., work of 3
Seed Miss E. R., ook of 256
axifraga, mo oxphology of 317
Saxton, W. 2 ork of 556
Schafinerell
Schin XK. Pe of 346
r, A.
Schinz, i. work of 3
Cc ?
Schlecter, R., work Se 46
Schneider, ie Titustriertes Hand-
buch” ae
Schreiner, Oswald, 3
Schiister Jl con of 82, 552, 555
Schu
Sc ile. E, week of 3
chwar sy work or 86, 556
Sclerotinia 346
(SUE 9 ess Be vent _ 87, 438
re er, F,
Seedlings, fe atts pe Sympetalae 553; of
Cent Sag 88; structure in Legu-
mi Bowes
Seeds, of Thentiiees 3
Selaginella 170
Rime rap akon 2 ue
Seward, A. C., work
Sexuality i in mosses Me i Opis 261
Sharp, Lester W. 8
Shelford, V. E. ig
Shull, Chates At ~, Bg of 433
Shull, Geo. H. 20, 256, 259, 260,
263, 3513 work
Sieve tubes, 340; of
iss odium
Marsilia ie “ol Preridium 349
Sinomenium 4
Sisyrinchium ealateen 136
Shinn er, J. J. aX, 152; age
428
Smilacin stellate, anatomy ’ 293
hispida, anatomy of 2
Smith, C. P., k
532
ere tuberosum, ingrowing sprouts of
Solidago racemosa, anatomy of 2
Solms-Laubach, H. Grafen zu, ah of 8x
s
170
nc egg in Equisetum 89
Spirec
pores “ nee. germination of 186
INDEX TO VOLUME LIV
563
Spratt, Ethel R., work of 552
Standley, P. C., work of 347
Stanhopea peru a 34)
sie
St
Stellaria Apo yao 407
Step. rk of 3
Stiles, "Walter, — a ate 255
Stolan iO
Stomata, of Hentictiioes Se; =f Cre-
pcsacgier ae $6
Stopes, e C., work of 438
Stoppel, B R, eek of 171
Strasburger, Eduard, biographical sketch
6
Stratification, and evaporation of vege-_
tation 42
Sugar cane, diseases of 554
e, seedling anatomy of 553
T
Tammes, T., work = 35%
Taraxia
Tarred Aaa Sees ‘of Be okra on, 550
Taubenhaus, J. J., of 432
Eaten esi of 550
Teonongia
— : 551
Textbook of botany
Fagaibaw. bg of 349
on; ee OF,
Tilia ricana, anatomy of 283
Tillandsia, an epiphytic 262
ie)
3
7
¥
-Turnips, inheritance in 259
U
Ulmus americana, anatomy of 284
Unit. onlin in maize 263
Uranthe
Uredinales, Sheloas of 439
Ur jeg 168; nuclear phenomena in
canes
Ursprung, i work of 435
Uvularia, morphology of 553
564 INDEX TO.VOLUME LIV . [DECEMBER 1912
V Wieland, G. R., work of 256
Pen? 25
Variation curves 77 ae nia
Vascular anatomy, of Dianthera 1; of Wolf, F. a eee . 5 5r
Salicales 175 Wolf, Frederick A.
Vermiculariopsis 347 ood, J.M edley, “Natal plants” 540
be la 3 47; Clarkae 412; morphology of Wound reactions in fern petioles 556
Viost 347 X
ve vilpina anatomy of 292
ogler, P., work of 77 Xenodochus 77
Volkensieila. 169 Xylopsaronius $2
W Af
Wangerin, W., work of 347 : oo. Shigéo 441
aie: '0; work of 342 Yuce
weer a ; R., 19
Weir, James R. work of 352, 547 i$
Welsford, E. J., work of 347, 556
Wernham, H. F., work of 347 Zopf, W., wry of 541
West Indian plants 169 Zschokkea
Wheat, inheritance in 260 Zygadenus eainiae 406
‘Wiegand, K. M., work of sey: Fostisterls 87
ANIMAL MICROLOGY
GTIGAL EXERCISES. IN MICROSCOPICAL METHODS An Improvement
‘That Pays for the Machine
By
MICHAEL F. GUY
Professor of ZoGlogy in the Sivas
of Cincinnati
An indispensable book for teacher,
2 eta student, or novice who wishes
a
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amination ogical ma
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and ation of material for the a,
microscopical work in a course in el Choco
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three hundred tissues and i Tie above i an accurate statement of the service rendered by
ay ae s for properly preparing them
or microscopical study are tabulated. R T:
Sufficient abaoat of the psa ir side emington — ypewriter
of microscopy is giv able the a ra ate Stiecar Kep
student to get atten acy series from peice eae
his microscope. Ry = apn
250 pp., 8vo; postpaid $1.88
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The Life History of Polysiphonia Violacea
By SHIGEO YAMANOUCHI.
54 pages, 10 plates, 8vo, paper, net $x.00, postpaid $r.05
of the group has never ee given. [ his S$ paper presents first the results of t the author’s studie
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en comes an unt of sp
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malities: finaly ‘hee is a discussion of the ~vtological phenomena and alternation of generations.
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