Skip to main content

Full text of "Botanical gazette."

See other formats




r 



\ 



t\* 




*> 




\>-\ 



J* 



9 



/ 






b 



1 






■\J 









\. 









BOTANICAL GAZETTE 



cf 



v 





«?K| 



< 



G^w^ 



/ 



THE 



/ 



/ 



£4- 



BOTANICAL 



GAZETTE 




EDITOR 
JOHN MERLE COULTER 



VOLUME L1V 



JULY-DECEMBER, 1912 



WITH THIRTY-SIX PLATES, ONE HUNDRED AND ELEVEN FIGURES, 

AND TWO PORTRAITS 




THE UNIVERSITY OF CHICAGO PRESS 

CHICAGO, ILLINOIS 



J 



iiot. Garden 
1913 



Published 
July, August, September, October, November, December, 19 12 



Composed and Printed By 

The University of Chicago Press 

Chicago, Illinois, U.S.A. 



/ 






TABLE OF CONTENTS 



cumarin 



Comparative anatomy of dune plants. Contri- 
butions from the Hull Botanical Laboratory 



Parnassia and some allied genera (with plates 

XIV-XVII) - 

Development of the microsporangia and micro- 
spores of Abut Hon Theophrasti (with twelve 



figures) 



PAGE 



I 



31 



The development of the vascular structure of 

Dianthera americana (with plates I-IV) - W 

The toxic action of organic compounds as modified 
by fertilizer salts (with five figures) 

Oswald Schreiner and 

The effect of external conditions upon the after- 
ripening of the seeds of Crataegus mollis. Con- 
tributions from the Hull Botanical Laboratory 

157 - W timer E. Davis and R. Catlin Rose 49 

The structure of the stomata of certain Cretaceous 

conifers (with plates V and VI) - - - W. P. Thompson 63 
Spermatogenesis in Equisetum. Contributions 
from the Hull Botanical Laboratory 158 

(with plates VII and VIII) - Lester W. Sharp 89 

The primary color-factors of Lychnis and color- 
inhibitors of Papaver Rhoeas - - George Harrison Skull 1 20 

Contributions from the Rocky Mountain Her- 

■ 

barium XI (with two figures) - Aven Nelson 136 

Beneficial effect of creatinine and creatine on 

growth (with one figure) - /. /. Skinner 152 

The life history of Aneura pinguis. Contributions 

from the Hull Botanical Laboratory 159 (with 

plates IX-XII) 

Plant geography of North Central New Mexico. 

Contributions from the Hull Botanical Labora- 
tory 160 (with seven figures) - /. R. Watson 194 
The perfect stage of Actinonema rosae (with plate 

XIII) -------- Frederick A. Wolf 218 

Undescribed plants from Guatemala and other 

Central American Republics. XXXV - - John Donnell Smith 235 
Influence of phosphate on the toxic action of 



Grace L. Clapp 177 



/. /. Skinner 245 



161 (with thirty-five figures) - Anna M. Starr 265 



Lula Pace 306 



V. Lantis 330 



v 



vi CONTENTS [volume liv 

PAGE 

The development of Blastocladia strangulata, n. sp. 

(with plates XVIII-XX) - J. T. Barrett 353 

The orchid embryo sac (with plates XXI-XXIII) Lester W. Sharp 372 

Growth studies in forest trees. 1. Pinus rigida 

Mill, (with plates XXIV and XXV) - - Harry P. Brcrwn 386 

Contributions from the Rocky Mountain Her- 
barium. XII - - - - - - Avert Nelson 404 

Two species of Bowenia. Contributions from the 
Hull Botanical Laboratory 162 (with four 
figures) - - - - - - - - Charles J. Chamberlain 4 X 9 

Life history of Cutleria. Contributions from the 
Hull Botanical Laboratory 163 (with fifteen 
figures and plates XXVI-XXXV) - Shigeo Yamanouchi 44 * 

The nature of the absorption and tolerance of plants 

in bogs - Alfred Dachnowski 503 

Ingrowing sprouts of Solanum tuberosum (with 

plate XXXVI and six figures) - C. Stuart Gager 5 J 5 

The abortive spike of Botrychium. Contributions 

from the Hull Botanical Laboratory 164 

(with twenty-one figures) - O.O. Stoland 525 

Plants which require sodium (with two figures) - W. J. V. Osterhout S3 2 

Briefer Articles — 

Eduard Strasburger (with two portraits) Charles. J Chamberlain 68 
A note on the generations of Polysiphonia 

(with one figure) - George B. Rigg and Annie D. Dalgity 164 
Absorption of barium chloride by Aragallus 

Lamberti C. Dwight Marsh 250 

. Artificial production of aleurone grains (with 

one figure) - - W. P. Thompson 33 6 

A new species of Andropogon - - - A. S. Hitchcock 4 2 4 

Evaporation and the stratification of vegeta- 
tion (with one figure) ----- George D. Fuller 4 2 4 

The perfect stage of the Ascochyta on the hairy 

vetch - - - - - George F. Atkinson 537 

Gautieria in the Eastern United States - - George F. Atkinson 53 8 

Current Literature 73, 166, 253, 339* 427> 54° 

For titles of book reviews see index under 

author's name and reviews 
Papers noticed in "Notes for Students" are 

indexed under author's name and subjects 



DATES OF PUBLICATION 

No, 1, July 15; No. 2, August 16; No. 3, September 21; No. 4, October 
15; No. 5, November 13; No. 6, December 16. 



ERRATA 

I 

. i, to title add index 1 , and append footnote Contribution from the Botanical 

Laboratory of the Johns Hopkins University, No. 24. 

P. 51, line 3 from bottom, for than read then. 

P. 57, line 14 from top, for carpel read carpels. 

P. 79, footnote 2, for Volger read Vogler. 

P. 88, footnote 34, for Combes, Raout read Combes, Raoul. 

P. 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 rubrutn 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. 

P. 127, line 28, omit also. 

P. 148, line 19, for Castilleja viscia read Castilleja viscida. 

P. 164, line 19, omit on before Griffitksia and Delesseria. 

P. 164, line 21, insert regularly before borne. 

P. 165, legend of fig. 1, for a Polysiphonia (?) read the plant referred to in 

this note. 

P. 191, last line, for Eracheinungen read Erscheinungen. 

P. 208, line 8, for practically read partially. 

P. 235, line 8 from bottom, omit hyphen between subtus and fusco. 

P. 252, line 11, for 37.095 read 37.95. 

P. 269, line 13, for into read in to. 

P. 274, line 11, for slight read slightly succulent. 

P. 277, line 1 of Celtis table, for (87-72) read (27-72). 

P. 281, line 1 of Ostrya table, for (66-95) rea( l (66-93). 

P. 297, line 11 from bottom, after reported insert (3). 

P. 393, line 2, for began read begins. 

P. 405 for Calochortus umbellatus read Calochortus euumbellatus ; line 10 

from bottom, for C. umbellatus read C. euumbellatus. 

P. 419, line 5, for in the Tropic read on the Tropic. 

P. 428, footnote 2, for 191 2 read 1911. 



r ol. LIV 




THE 








July 1912 




Editor: JOHN M. COULTER 



CONTENT* 



The Development of the Vascular Structure of Dianthera 



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 Mollis 

Wilmer E. Davis and R. Catlin Rose 



The Structure of the Stomata of Certain Cretaceous Conifers 



W. P. Thompson 



Briefer Articles 



Eduard Strasburger 



Charles J. Chamberlain 



Current Literature 



The University of Chicago Press 



CHICAGO, ILLINOIS 



Agents 






THE CAMBRIDGE UNIVERSITY PRESS, London and Edinburgh 

WILLIAM WESLEY & SON, London 

TH. STAUFFER* Leipzig 

THE MARUZEN -KABUSH1KI --KAISHA, Tokyo, Osaka, Kyoto 



m 



Uhe 



Botanical (Ba^ette 




B /fcontbls Journal Embracing all departments ot botanical Science 

dited by John M. Coulter, with the assistance of other members of the botanical staff of the 

University of Chicago. 

Issued July 15, 1912 



Vol. LIV 



CONTENTS FOR JULY J912 



No 



nil: DEVELOPMENT OF THE VASCULAR STRUCTURE OF DIAXTHERA AMERI- 
CANA (with PLATES i-iv). \V. Ralph Jon --------- 

THE TOXIC ACTION' OF ORGANIC COMPOUNDS AS MODIFIED BY FERTILIZER 

SALTS (with five figures). Oswald Schr r and /. J. Skinner - 

THE EFFECT OI EXTERNAL CONDITIONS UPON THE AFTER-RIPENING OF THE 

SEEDS OF CRATAEGUS MOLLIS. Contributions from the Hull Botanical 
Laboratory 157. Wilmer E. D is and R. Callin Rose 

E STRUCTURE OF THE STOMATA OF CERTAIN CRETACEOUS CONIFERS 
(with pl.yti and vi). IE. P. T; mpson --------- 

BRIEFER ARTICLES 

Eduard Strasburger (with two 1 rtraits). Charles J. Chaml lain - - - - 

:jrrent literature 

BOOK REVIEWS - - - - - - 

THE CHICAGO TEXTBOOK. AN ELEMENTARY TEXT 



1 



9 



6 



6 






MIXOR OT1CES --------------- 7 6 

NOTES FOR STUDENTS - - - - - - 77 



The Botanical Gazette is published monthly, 
of single copies is 75 cen . 



* 



1 



Po 



« 



The subscription price is S7.00 per year; the price 

[Postage is prepaid by the publishers on all orders from the United States, 

Mexh , Cuba, Porto Rico, Panama Canal Zone. Republic of Panama, Hawaiian Islands, Philippine 

Islam , Guam, Tutuih? -an a), Shanghai. r Postage is charged extra as follows : For Canada, 35 cents 

on annual sub Tptions (total $7*35), on single copies, 3 cents (total cents . for all other countries in the 

al Union, ;ents on annual subscriptions tai $7,84), on single copies, xi cents (total 86 cent 

Remittances hould be made payable to The I uversitv of ChidKgo Press, and should ! Chicago or 

New Y c excha . postal or express money order, if local check is used, 10 cents must be added for 

ilection. 

The following agents have been appointed and are authorized t< piote the prices indicated: 

the Brit Kmpire: The Cambridge University Press Fetter Lane, London, E.C., and William 
Wesley & S 2^ E ex Street, Strand. London. Yearly subscriptions* including postage, £l 12*. 6 
each; sir opies. dud in g postage, .6 each. 

Fort Contin t\ r ope : Th. Stauffer, tmversita: trasse 26, Leipzig. Germany. Yearly 
scription <clu ng postage, M. ^ each sin e copies, including postage, M. 3.60 each. 

For Japan and 1 rea: The Maru/en-Kabusl -Kaisha, n to 16 Nihonbas! Tori Sane home, Tokyo. 
Japan. Yearly subscriptions, including p- :ag en 15 .75 each; single copies, deluding postage, Ven 
1*75 each. 

Claims for missing numbers be made bin the mot wing the ret ir month of publ 

cati s. Tiie pubii ters expect to supply m -ung r\ 5 free only 1 1 they have been lost in transit. 

Business correspondence should be 1 dre • le Unive. 1 Pre! Chicago, Til 

Communications for the editor e d to him at The If of Chicago, Chic 

Contributors juested to itihe and per names with p icular care, to use the metric 

vstem of w and measar 1 cit m nv the form n in the | ges of the Hot a ic 

es are r ac spted unk the author is v ling to pay *»* 



T 



V-* 



Papers b- exce -tvnpi 

Cost of the litional ] . in whic ca number of p in the volume corr* I tngly increase 

Illustration are furn- :ed without cost author onl hen su able rlginals are supplied. A 
of the s on made ;n the nary ni 1907, be sent a application. It is advisable 

c Ter with rs as to iliustratic red in ay article to be *rt 

Separates, red. mi be ordere ac .nice mblicat a. Twent five separate of original 

artic r ers v 1 be supp ratis. A table approximate c additional separate 

printed n order blan h aec mpan 3 the pn * ; a will | on re* est. 

Entered ? i?r, xSq6, er ,'asttc td-t ider Act * Mai 






VOLUME LIV 



NUMBER i 



THE 



Botanical Gazette 



JULY 19 1 2 



THE DEVELOPMENT OF THE VASCULAR STRUCTURE 

OF DIANTHERA AMERICANA 

W. Ralph Jones 

(with PLATES i-iv) 

In 1907, Theo. Holm (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 p 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 



2 BOTANICAL GAZETTE [juiy 



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 
0.5-1 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 capita te-spicate inflorescences of violet or nearly white 



flowers. 



the 



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. 
The basal part of the erect shoots and also the rhizomes, there- 
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 
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-historv. 



i 9 1 2] - JONES— DIANTHERA 3 



As Holm (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, Holm says that the plant 
is polys telic; 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. i). 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 0.75-1 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 [jm.v 



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 Schaffnit (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- *3>- 

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, 

>n wet sand. The testa soon split, the 
Further growth now forces upward 



hypocotyl pushing through 
the upper end of the hypoo 



ne or both of the cotyledons. The latter 
soon become green, continue their growth, and function photo- 
synthetically for some time. The plumule is rather tardy i n 
starting its growth. 



1 9 i 2] JONES— DIANTH ERA 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 
Teeghem. Fig. 17 shows a diagram of the path of the vascular 
tissue at this stage. 



STAGE 11 



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- 
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 



this 



ermis are verv nearlv as in the 



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 
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 Dassiner off nearly 



igi2] JONES— DIANTH ERA 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 in 



With the development of the second pair of opposite leaves at 
right angles to the first pair, and directly oyer 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 [jutv 



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 a 
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 
hypocotyl and 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. 



i 9 1 2] JONES— DI A NTH ERA g 



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 



IO 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. 



this node 



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. 



1 9 1 2 ] JONES— DI A N THERA 1 1 



At this stage, the oblique cross-arms are imbedded in the 



parenchymatous tissue, there b 



3f any sheath. After 
fused bundles become 



more or less well marked 



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 



the 



node as a type, we find (fig. 3), just abov 



sheath 



that every bundle is surrounded by a regular endodermal 



differentiated 



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 Dass downward to the 



19 1 2] JONES— DI ANT HERA 1 3 



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. 29) , 
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 
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 



come 



fork at all. 



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 



end 



permanent re< 
ment, slightly obscured, it is true, by 



thickening. It is comparable in this respect to a fern 
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 
tern, when the mature structure is once formed, the main axis con- 
tinues its growth, each succeeding internode having the mature 



14 BOTANICAL GAZETTE [july 



mam 



5 



structure. In Dianthera americana, on the other hand, the 
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 meris teles, 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 meris teles. 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 bv a laver. several 



abov 



in thickness, of closely packed parenchymatous cells. This 
is continuous with the parenchyma of the individual meristeles, 
1 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 



ipiderm 



like those of the mature plant. As Holm has already accurately 
described and figured these tissues, nothing more need be said of 



19 1 2] 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 
Holm. One correction must be made, however. Holm 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 
right 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. S3)- On entering the node below, 
these sheaths open on the inside, the ends connecting so as to form 
a 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 Holm. 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 Holm 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 variabilitv. Two seedliners of the 



same 



same number of leaves developed, may 



very great differences in the degree of differentiation of vascular 
tissue, cambium, endodermis, etc. For instance, a seedling of the 



1 9 1 2] JONES— DI AN TH ERA 1 7 



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 



may 



the next, may or may 



A couple of examples may be given. Counting the internodes back 



finds any trace of medullary 



the 



cal meristem, being 
The central bundle 



/elops in the third internode, and it may 
nodes below this. An abnormal seedlinj 



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 



bundle 



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. In a 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 
m its younger state, had grown together at the base, owing to the 



amount 



the 



internode 



between them 



base, the endodermis 



the endodermis 



forms a com 



the fused bundle 



trace to be inserted between its halves. 

In the basal internodes of the branches, there are usually 
peripheral bundles. Rarelv. however, one of the side bundles 



be differentiated 



mature 



At the close of the growing season, the rhizomes produced at the 
base of the seedlings have developed the mature type of structure 



thei 



Growth 



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 entering 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 Holm'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 Holm 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. Holm mentions that the central bundle may sometimes 
be lacking, but an examination of several hundred internodes of 



mature plants has failed 



One single 



i 9 1 2] JONES— DI ANT HERA 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 



been described (fig. 1). 



minute 



similar to that 



the seedling. 



there is more of the 



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. 
Holm, 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, readilv observed in the Detiole as one central, very broad, 



From the anastomosing bundles 



much smaller 



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 Holm. 
This giving off of a single leaf trace, which trifurcates while yet in 



found in all of the Acanthaceae. 



Tieghem (11), the conformation 
It should be noted, however, that 



DeBary (3, p. 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 

not pectinated." 
been fully described 

seedling 



with 



by Holm. In structure they are identical with 

nence the correction concerning the presence of the marginal strand 

of collenchyma in the blade has to be made here 



The axillary buds of the mature plant 

As in the seedling, a bud is usually formed in the axil of each 
leaf. Those at the base of the aerial shoot usually develop into 
rhizomes, or more 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 



may or may 



The 



ordinarily develop into inflorescence axes. As Holm 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 



forms a stronglv developed endodermis. This 



but 



remains as a ring, marking the boundary, rather indistinct at 



the 



The paren 



chymatous tissue of the latter differs from that of the former 



made 



smaller 



and in containing a very much 
The general appearance of a cross- 



monostelic stem 



b 



compare the insertion of a well developed 



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. 



1 9 1 2] JONES— Dl A N THERA 2 1 



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 



becoming normally oriented. Then the ring of the six 



incoming leaf trace become 



common 



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 



by 



s five petals. At first the latter are separate, but s 
form the corolla tube. About the same time that 



mounds appear, marking the primordia 



stamens 



more 



stamens (five occur in some of the Acanthaceae 



genera there are two stamens and three staminodia). The ovary 
grows up as a ring (fig. 40) , the sides nearest and farthest from the 



plant being slightly (10-15 /*) higher (fig. 50). The petals 



the stahiens being carried up on the corolla tube 
Le ovarian "ring" closes in over the top and continues its growth 
form the pistil with its deeply two-lobed stigma. The placentae 

from the opposite walls of the ovary, near its base. Two 



vules arise on each 



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 Holm, 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., 



1912] JONES— DIANTHERA 23 



D. pedoralis 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 Holm, 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- 

The interxvlarv phloem of Thunbereia and 



oem (Thunbereia. Hex 



malities are known. The interxylary 

others is well known. Intraxylary ph 

ins, Barleria, etc.), medullary phloem (petiole of Acanthus moll 

and even medullary bundles (Acanthus spinosus, etc.), have i 

been described. It is thus seen that the family shows irregul 

ties 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 



hymatous cells of the medull 



from 



endodermis 



m 



Now let us examine the fate of the parenchyma 



derived from the plerome. That part 



within the endodermal 



becomes so mo 



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 Tieghem and Duliot (12, p. 275) say in their definition of 
astely, that the bundles are "directement nlonses dans la masse 



i 9 1 2] JONES— DI AN TH ERA 25 

generate du corps qui ne se separe pas alors en ecorce et conjonctif" 

(P- 2 75)- 

Strasburger (9) distinguishes between the inner layer of the 



which is a morphological laver. and the endodermis 



m 



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 io). 

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 Col (i), in his work on the arrangement of 
bundles, calls "serie M\" He defines this type as follows 
2 42): "faisceaux normaux rentrant dans la moelle de la tige. lis 
s accolent inferieurement a d'autres faisceaux medullaires, et tous 
ceux des entre-noeuds les plus inferieure de la tige se poursuivent 

et se terminent isolement 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 Lignier (7), Kruch (6), and Col 

V 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. 

Col (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 



iqi2] 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 beine astelic, and in Dossessine medullarv 



vascular tissue. 



Summary 



The mature plant of Dianthera americana is astelic, instead 
of polystelic, as claimed by Holm. 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. 

Johns Hopkins University 



Baltimore, Md. 



LITERATURE CITED 



• <-ol, A., Relation des faisceaux medullaires avec les faisceaux normaux. 
Journ. Botanique 16:234. 1902. 



2. 



1 Recherches sur la disposition des faisceaux dans la tige et les 
feuUles de quelques dicotyledones. Ann. Sci. Nat. Bot. VIII. 20: 1. 1904. 

3- -DeBary, A., A comparative anatomy of the phanerogams and ferns. 
English translation. Oxford. 1884. 

4. Gregoire, V., La valeur de la couche amylifere dans la tige, et la theorie 
stelaire de Van Tieghem. Ann. Soc. Sci. Bruxelles 34:5-12. 1910. 



28 BOTANICAL GAZETTE [july 



5. Holm, Theo., Ruellia and Dianthera; an anatomical study. Box. Gaz. 
43:308. 1907. 

6. Kruch, 0., Fasci midoll. d. Cichoriacees. Ann. R. Inst.Bot. Roma. 1890. 

7. Lignier, O., Anatomie des Calycanthees, des Melastomacees, et des 
Myrtacees. Diss. Paris. 1887. 

8. Schaffnit, Ernst, Beitrage zur Anatomie der Acanthaceen-Samen. Inaug. 

Diss. Leipzig. 1905. 

9. Strasburger, E., Ueber den Bau und Verrichtung der Leitungsbahnen. 



J 



theory; a history and a criticism. Science 



Progress 5:133. 1896. 

11. Van Tieghem, Ph., Relation entre la production des cystolithes et la con 
formation de la region stelique du petiole dans la nouvelle famille deJ 
Acanthacees. Journ. Botanique 21:25. 1908. 

12. Van Tieghem et Douliot, Sur la polystelie. Ann. Sci. Nat. Bot. VII 



3:275. 1886. 

Vesque, J., Memoire sur Tanatomie comparee de l'ecorcc 
Bot. VI. 2:82. 1875. 

Weiss, J. E., Das markstandige Gefassbiindelsystem in 
zu den Blattspuren. Bot. Centralbl. 15:401-415. 1883. 



Ann 



EXPLANATION OF PLATES I-IV 



All 



xyl 



In the 
In figs. 



3-9 the endodermis is represented by cells. The index letters are as follows: 
A.R., adventitious root; 2J, bract; BR, branch; BR.T., branch trace; C, 
carpel; C. B. central bundle; CL, calyx; CO T, cotyledon; CR, corolla; END, 
endodermis; EP, epidermis; ESP, endosperm; I A., inflorescence axis; £, 
leaf; L.T., leaf trace; M.PH., medullary phloem; P.B. peripheral bundle; 
PC, procambium ; PPH, protophloem; P.R., primary root; PX, protoxylem; 
5, stamen; ST, stem; T, testa; T.A., transverse arm. 

■ 

PLATE I 

Fig. 1. — Reconstruction of the vascular system of two adjacent mature 
nodes. 

Fig. 2.— Diagram of the paths of the peripheral bundles of a mature stem. 

Figs. 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. 

Fig. 9. — Transverse section through the upper part of an internode of an 
old seedling, showing one central and four peripheral bundles; X45. 

Fig. 10. — Part of a sagittal section of a seed, directly opposite the micro- 
pyle, showing the testa with its thickened epidermal cells, and the endosperm 
of two layers; X185. 



1912J JONES— DIANTH ERA 29 

Fig. 11. — Sagittal section of a seed; X 12. 5. 

Fig. 12. — Longitudinal section of a seed, made perpendicular to the plane 
of the section shown in fig. 11, and through the line mn; X 12. 5. 



plate 11 



Fig. 13 — 



hyp 



seed, just below the insertion of the cotyledons; X 185. 



hyp 



Fig. 14. — Transverse section through the middle portion of the same 



the stele; X185. 

Fig. 15. — Habit sketch of a seedling; stage I, with cotyledons still inclosed 
within the testa; X1.5. 

Fig. 16. — Transverse section of the upper portion of a first-stage seedling, 
just below the insertion of the cotyledons, showing the two "double" cotyle- 
donary traces; X185. 

Fig. 17. — Diagram of the paths of the bundles in a seedling, stage I. 

Fig. 18. — Diagram of the paths of the bundles in a seedling, early phase 
of stage II. 

Fig. 19. — Habit sketch of a seedling, stage II (late phase); Xi. 

Fig. 20. — Diagram of the paths of the bundles in a seedling, late phase of 
stage II. 

Fig. 21. — Diagram of the paths of the bundles in a seedling, early phase of 
stage III. 

Fig. 22.— Habit sketch of a seedling, stage III; X 1. 

Fig. 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 three protoxylem, and three protophloem elements; X380. 

Fig. 24. — Transverse section of the same bundle as shown in fig. 23, at a 
lower level, just at the top of the fork; X380. 

Fig. 25. — Transverse section of the same bundle still lower down, the 
forking complete; X380. 

Fig. 26.— Surface view of a glandular hair; X380. 

Fig. 27.— Longitudinal section of a glandular hair and neighboring 
epidermis; X380. 



Fig. 28. 



uppermost 



seedling, showing the two procambial bundles of the traces of the uppermost 
Pair of leaves imbedded in the ground meristem; X380. 

Fig. 29.— Diagram of the paths of the peripheral bundles in a seventeenth- 
stage seedling (near end of growing season), showing the gradual development 



typ 



PLATE III 



Fig. 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. 



30 BOTANICAL GAZETTE [july 



Fig. 31. — Habit sketch of an old seedling (stage XVII), near end of grow- 
ing season, showing the development of rhizomes from the basal axillary buds; 

X0.5. 

Fig. 32. — Transverse section of the margin of the blade of a mature leaf, 

showing the collenchymatous strand; X210. 

Figs. 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. 

Fig. 36. — Transverse section of the stele of the basal internode of a mature 
inflorescence axis; X45. 

Figs. 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 



Figs. 42-45. — Series of successive transverse sections through the upper 
part of a node, showing the insertion of an inflorescence axis; X 50. 

Fig. 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. 

Fig. 47. — Longitudinal section of a young flower, not quite median, 
showing the bract, calyx, corolla, one of the stamens, and the edge of carpel; 
X50. 

Fig. 48. — Longitudinal section of a young flower, made perpendicular to 
that shown in fig. 47, along the line mn, showing the two large stamens free 
from the corolla; X50. 

Fig. 49. — Sagittal section of a slightly older flower, showing the formation 
of the ovarian cavity; X 50. 

Fig. 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; X50. 

Figs. 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; X 22 . 5. 



BOTANICAL GAZETTE, LIV 



PLATE I 




DEL. 



JONES on DIANTHERA 



BOTANICAL GAZETTE, LIV 



PLATE II 





v 

I 



■ 

: 



18 



END 



COT 



17 



•-...-• 



Y 



♦ L 



COT 








COT 




COT 








PPH 



COT 








JONES on DIANTHERA 



BOTANICAL GAZETTE, LIV 



PLATE III 




JONES on DIAKTHERA 



BOTANICAL GAZETTE, L1V 



PLATE IV 








M 











JONES on DIANTHERA 



THE TOXIC ACTION OF ORGANIC COMPOUNDS AS 

MODIFIED BY FERTILIZER SALTS 1 

Oswald Schreiner and J. J. Skinner 



(with FIVE figures) 



former 



compound isolated from 



* 

unproductive soils, was presented. The results obtained with this 
organic soil constituent, showing its effect on growth and absorp- 



from 



composition 



obtaining further information 



other 



bodies known to be harmful 



with 



some of the results obtained in experiments 



mixtures of different composition 



The compounds studied, though not actually isolated from 



common constituents of Dlant debris, or result from 



and 



soil. 



ge number of such com 



growth was given in an earlier paper. 3 Of these compounds, 
cumarin was selected for the continuation of these researches 



harmful even in minu 



million 



o 



common constituent of a number 



remains of which g 



obtained 



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. 

2 Schreiner, O., and Skinner, J. J., Some effects of a harmful organic soil con- 
stituent. Bot. Gaz. 50:161. 1910. 

3 Schreiner, O., and Reed, H. S., The toxic action of certain organic plant 
constituents. Bot. Gaz. 45:73, 271. 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 2 O s , NH 3 , and K 2 0, m 
10 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. 



p 2 o s 




NMj 



Fig. 1. 



represent the 66 culture solutions. 



triangular diagram, with the points 



potassium 



m is used as a guide. In this diagram 
c, 56, and 66, are the cultures which con- 
, calcium acid phosphate, sodium nitrate, 
respectively; that is, the total of 80 ppm. 

The line 

and NH 



NH\. or K 



mixtures of P*0 



in 10 per cent differences; 



2^5 



3 



cultures between 1 and 56 



i9i 2] SCH REINER & SKINNER— FERTILIZER SALTS 33 



mixtures of P 7 e and K 



the 



mixtures 



NH 3 . The cultures in the interior of the triangle contain mixtures 
of all constituents, differing in io per cent stages one from the other, 
the composition depending upon its position in the triangle; those 
nearer the P 2 s apex consisting chiefly of phosphate fertilizer, 



NH 



K 



more 



scheme 



reader is referred to an earlier paper. 4 

Two sets of these 66 culture solutions were prepared, one of 
them containing in every culture io ppm. of cumarin. The total 
concentration of the nutrient elements P 2 O s +NH 3 +K 2 was in 
all cases 8o ppm. The culture solutions were contained in wide- 



mouth bottl 
the manner 



The culture solutions 
hnnp-es beiner 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 nlants was determined at the termination 



: experiment. The first experiment with 
December o and discontinued December 2 



ppm 



was strikingly noticeable in the difference between the plants grow- 
ing in the two sets of cultures. The appearance of plants growing 



ns containing cumarin is very characteristic dnu 1 
from the effect on wheat of anv other toxic com 



rked 



The leaves are shorter and broader 



normal 



remaining 



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 

4 Schreinek, O., and Skinner, J. J., Ratio of phosphate, nitrate, and potassium 
on absorption and growth. Bot. 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 ioo 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. 



nfluence of the phosphate on the harmful 



cumarin is perhaps most strikingly shown in the difference between 
the plants growing in the culture solution containing no phosphate 



nam 



and 



mmediately above this, containing 

■tilizer mixture. Where phosphate 

the cumarin is most marked. Ab 

of the cumarin steadily decreases 



it, the 
harm- 



the triangle disappears altogether, so far as the eye can detect 
s in the appearance of the plants in the normal and cumarin set. 
The effect of the phosphate in overcoming the harmful action 



IQI2] 



SCH REINER &• 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. i. 

TABLE I 

Showing the influence of phosphate in overcoming the harmful effect of 

CUMARIN 



Percentage of 

P'Oj IN FERTILI- 
ZER MIXTURES 



Parts per mil 

lion OF PaOs 

IN ORIGINAL 
SOLUTIONS 



O 
10 

20 

30 
40 

So 
60 

70 

80 

90 

100 



Number of 
cultures 
included 



Green weight of cultures 



Without 
cumarin 



With 
cumarin 



Relative (with 
out cumarin 
= 100) 



O 

8 
16 

24 

32 
40 

48 

56 
64 

72 
80 



11 
10 

9 

8 

7 
6 

5 
4 

3 
2 



21-773 
22.408 

20.339 

17- 143 
15.008 

11. 188 

9"3 
6.915 

4-I7I 
2.388 

0.932 



I5-370 
18.835 
17.140 

I5-350 
14.085 

11. 150 
9.005 

6.485 
4-330 
2-530 

0-955 



7o 

84 

84 
90 

94 
100 

99 

94 

104 

106 
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 
rose to 84, 90, 94, and 100 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 
is 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 2 s , NH 3 , and K 2 0, as was 



36 



BOTANICAL GAZETTE 



[JULY 



done in the case of the dihydroxy stearic acid experiment. This 
is accomplished by taking the cultures contained in the smaller 



i 



triangles formed at each angle of the larger one shown in fig. 
that is, the cultures contained within the triangles i, 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 



P 2 



5 



CUAtA/?/A/ 



/EfZ>* T/tS£- G/?OWTH 



/VO /?***£. =r 43.3 \ 
CUMtAWt/ = 36.S \ 

= 7.3 \ 






&9&¥TH 



KoO 



Fig. 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 



showed 



:h only 83 per cent of the normal. 

second set of experiments with cumarin was made 



conducted as in the first experiment. This grew from 



January 1 2 to January 
The cumarin-affecti 



plants showed the same characteristic 
n 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 10 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 2 O s +NH 3 +K 2 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 



cumann 



In table II are given the results for the P 2 5 , 



NH,, and KX), separately, under the normal 



cumarin set. 



TABLE II 



Total milligrams of p 2 o 5 , nh 3 , and k 2 o removed from the 36 culture 

containing all three of these ingredients 



Total absorption in milligrams 



Normal 



PA 

NH 3 
K 2 



Cumarin 



Relative 



278.5 
482.6 
618.2 



Percentage of 

cumarin cultures 

above normal 



264. 5 

415-3 
592.6 



95 
86 

96 



57 
22 

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 91 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 2 5 +NH 3 +K 2 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 



i9i 2] SCH REINER & 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 
hght on this phase of the question. For this comparison the 
aldehyde vanillin was selected. This was known to be toxic from 
former experiments, was known to be oxidized by the plant roots, 
and was further known to be more readily oxidized when nitrates 



4 c BOTANICAL GAZETTE [JUL* 

were present, 5 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 10 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 50 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 

s Schreixer and Reed, Jour. Amer. Chem. Soc. 30:85. 1908. 



ig 1 2] 



SCHREINER & SKINNER— FERTILIZER SALTS 



41 



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 



R>o 




Fig. 3. — Showing the relative growth of normal and vanillin cultures in solutions 
high in phosphate, nitrate, or potash, respectively. 



show 



compounds, it was thought, should 



ence of two such widely different poisons, and the scope of the 



experiment 



lend itself to showing such differences in metabolism or fertilizer 



requirement, and thus throw some 



oxidizin 



experiments 



42 BOTANICAL GAZETTE [july 



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 6 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 per cent of the normal. The chief interest, however, centers 

6 Schreiner, O., and Reed, H. S., The role of oxidation in soil fertility. Bull. 
56, Bureau of Soils, U.S. Dept. Agr. 1909. 



19 1 2] SCH REINER fir 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 ffree.n weight of 77 r>er cent of the normal. 



P 2 5 



. G * 4 ' — Showing the relative growth of normal and quinone cultures in solutions 
hl gh in phosphate, nitrate, or potash, respectively. 

the mainly nitrogenous 67, and the mainly potassic 83. It is 



most efficient 



coming the harmful 



experiment with quinone was repeated, and this time 



solutions were 

-Lnis second quinone experiment lasted from 

tt showed the same creneral slender aDDeara 



cumarin experiment 



44 



BOTANICAL GAZETTE 



[JULY 



well as again showing the influence of the potassium fertilizers as 
above described. In this experiment the green weight 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 2 5 +NH 3 +K 2 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 2 s , NH 3 , and K 2 
removed when auinone is oresent. 



In table III are given the 



results for the P 2 O s , NH 3 , and K a 
conditions and in the quinone set. 



TABLE III 

« 

Total milligrams of p 2 o s , nh 3 , and k 2 o removed from the 36 culture solutions 

containing all three of these ingredients 






Total absorption in milligrams 



Normal 



PA 

NH 3 
K,0 



300 

S7i 
696 



•4 
■5 
•5 



Quinone 



173-6 
506.8 

646.5 



Relative 



58 

93 



Percentage of 

quinone cultures 

above normal 



8 
II 

36 



An inspection of these figu 



more normal 



than the other two nutrient elements. 



shown 



relative absorption in the 
quinone cultures showing 
NIL, and K 2 0, respectively, in the last column 



column and bv the number 



normal 



1912] SCHREINER &■ SKINNER— FERTILIZER SALTS 45 



We 



therefore, the interesting case of a toxic oxidizing 



overcome 



normal oxidative power of the root, accompanied by a 



element 



normal 



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 
respective 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 



effect 



s. 



This different action of fertilizer salts on the toxic com- 
pounds is also illustrated by the diagrammatic representations in 
hg- 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. i 
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 



p„o 



5 




KoO 



Fig. 5. 



triang 



representation 



1 

growth 



in the 



uma 



greatest growth is diagramma 



marked 



When cumarin 



direction 



greatest 



may be diagrammatically shown by the circle marked cumarin 
With quinone, this region of growth was shifted toward the potasl 
angle, and with vanillin toward the nitrate angle, as illustrated ir 
the diagram. 



1912J SCHREINER 6* 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 
reducing 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 



same 



That 



mful bodies occur in soils has been am 



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 



biochemical 



remains in the soil: in other 



mana 



ment, and the altered biochemical 



remains 



sim 



The action of fertilizers on soils is a much contested 
but the weight of evidence is against the assumption 
effect is due altogether to the added plant food. If so 
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 in 
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- 

>erly used. To this influence of fertilizers on soil 



impro 



due 



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 of Soils 
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 1 57 

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. Nobbe 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 

During this period, it is assumed that the 
tianges, at the completion of which germina- 



on the part of the seed. 



may take place. This period of preparation for germination 



een termed the 
may be made 



The term after-ripening 



limit 



germination; changes involving the release 
piratory enzymes, thus leading to rapid metab 
m or other modifications of incasing structure 
r or oxygen supply or even mechanically 1 



growth. 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 
°f 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 

4 9 [Botanical Gazette, vol. 54 



50 



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. Muller (15) found that the seeds of 
Eichhornia and Heteranthera germinate only after desiccation. 
Crocker (i), working on the seeds of various water plants, includ- 
ing Eichhornia and others reported by Fischer, 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 (ii) 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 Lummis (17) found that many weed seeds that 
failed to germinate under ordinary germinating conditions germi- 
nated more or less readily after freezing. Pammel 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 



19 1 2] DAVIS 6* 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 
°f 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 



rpel. The seeds were than placed upon wet cotton 
both in the laboratory and the greenhouse. They 



this condition for months without 



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 



him 



remarkable 



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 slowlv and never reach the size attained in case the 



hyp 



the 



contained 



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 

■ —a 



dishes 



temperatures 



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 



remove 



While 



removed 



knife, yet many suffered more 



ced upon the ice. The 



broken 



IQI2] 



DAVIS 6* 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 in a mass. The loss in after-ripening 
can be greatly reduced by thoroughly washing the seeds before 
placing them in the cold. 

■ 

TABLE I 



No. 

culture 



14 

18 

17 

9 
8 

16 
19 



No. 

seeds 



Condition of seeds under 

treatment 



400 
400 
400 
400 
400 
400 
400 
400 



Carpels off 

Carpels on 

Carpels off 

Carpels on 

Carpels off 

Carpels off 

Carpels off (seeds dry) . . 

Carpels off (seeds under 

water) 



Tem- 
perature 



No. 
days at 
low tem- 
perature 



In light 



In dark. 



Germi- 
nation 
within 
10 days 



5-6° 

5_6 o 

5-6° 



5-6' 



Total 
number 
germi- 
nated 
after 
20 days 



96 




221 


242 

96 




O 
122 


242 

96 
96 

96 




^^■HMI^A 


O 

5 

244 




150 











264 

o 

250 

o 

219 

o 



Germination at io°— 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 high, running from 90 to 98 per 
cent. 



When the above seeds were removed from the 
ced in a water bath at a temperature of io° to 1 : 



erminate 



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 



the cold to the temperature of the greenhouse, the 



germination covered a much shorter time, as will 



showed 



removed from the 



signs of after-ripening; when they were 

they decayed. The failure to af ter-ripen under water was probably 



insufficient 



with 



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 



No. culture 



I 

2 
21 

4 

24 
IO 

20 

5 
3 

7 



No. seeds 


150 


150 


150 


iSc- 


iSo 


150 


IS© 


150 


150 


ISO 


150 


+ 



Temperature 



5~6 

o 

o 

2 to - 

2 tO - 
2 tO - 

5-6 
5-6 

5-6 

o 



3 
3 
3 









No. days 


Germina- 


Germina- 


at low 


tion 


tion 


tempera- 


within 


within 


ture 


5 days 


10 days 


73 


log 


112 


73 


45 


68 


90 


82 


83 


75 








77 








114 








130 








130 








90 


5 


5 


90 








90 









Remarks 



Treated without oxygen 
Treated H 2 with 2 per 

cent oxygen 
Treated without oxygen 
Treated without oxygen 
Treated H 2 with 2 per 

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. i, 109 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. 



i9i A 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 KMn04. 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 o. 25 cc. 
to 1 cc. 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 i in which the 
temperature at the beginning was q°-io° C. Tap water was used 
in the bath and the temperature varied with the season, ranging 
from the above temperature to as high as 2 2° 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 



No. 



I 

I 

2 

3 
4 



No. 

SEEDS 


Carpels 


Temp. 


No. 

DAYS 

IN 
BATH 


Light 


M 

3 

< 

P 


Germination during 


\ 


On Off 


Mar. 


Apr. 


May 


June 


July 

11 

11 

1 




Aug. 


■ s 


400 
4OO 
400 
400 
40O 


/ 
1 


1 
1 
1 


9-22 C. 
9-22 C. 
9-22 C. 
9-22 C. 

9-22° C. 


275 
264 

275 
275 
275 


/ 
/ 

/ 


/ 

/ 


40 

8 

9 

5 



25 

9 

1 

2 



IS 
12 








II 
17 

7 





1 

3 
1 






I03 
60 

7 




determine 



the 



J 3 



time 



C. 



temperature for 10 days, when it was removed 



the ice chest at a temperature of about 
^nation was kept up until September, or 
the seeds germinated during this time, alt 



o 



C. This 10-day 

T>in da vs. None 



exposed one-half of that time, or 70 days, to a temperature most 
suitable for after-ripening. The high temperatures appear to have 



temperatures 



im 



testas in after- 



removed from 50 seeds and the embry 



temperature 



C. 



embryos showed signs of germination 



nd of 
They 



then removed from 



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 






IQI2] 



DAVIS & ROSE— AFTER-RIPENING 



57 



time to high tempera t 



the cotyledons b 



take 



ripening 



importance of water as a factor in the after-ripening of the 

)hasized. Those seeds kept 



em 



thoroughly wet during this process gave the best results, as indi- 

the germination when removed from the cold. The 



cated 




within 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 oeriod. In order tc 



determine 



at the carpels and testas interfered with the taking 
the embryo, we took two lots of seeds, one with 



soaked in water at room 
were then removed from i 



rpels removed. Each lot was 



The testas 
These three 



with carpels intact, one with 
and testas removed, were dIj 



in Petri dishes and left in an ice chest at about f C. for 14 days. 
At the end of this period the camels and testas were removed from 



them on. and the 



ent of the embryos determined for t 
mbryos were dried in vacuo over H 

fere made in dunlirate and arp crivpn i 



4 



three conditions. The 
The determinations 



TABLE IV 



No. seeds 
treated 



Condition of 

embryos during 

treatment 



42 

2 9 

44 

44 

3o 



Carpels on 
Carpels on 
Testas on . 
Testas on . 
Testas off . 
Testas off . 



Wet weight 

of embryos 

in grams 

O.5114 
O.3186 
O.4018 
O.6056 
0.6866 
O.4810 



Dry weight 

of embryos 

in grams 



O.3844 

o. 2396 

0.2730 

0.4180 
0.4100 
0.2904 



I 



Water content 
in grams 



Water content 
in percentage 



O.127 

O.0796 

0.1278 

O.1876 

O.2766 

O.1906 



24.8 

24.9 
32.5 
30.9 

39-4 
39-6 



Gassner (6) has shown that seeds of two South American 
grasses, C Moris 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 9 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, 
Gassner found that P. dilatatum after-ripened in 1 to 2 weeks in 
dry storage at 5o°-6o° 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. Kinzel (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 o° C, while at — 2 C. 



to — 3 C. it makes 



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 



the 



rupturing 



means of which water or oxygen are permitted to enter. Especially 



19 1 2] ' 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 
after-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 

to inhibit the Drocess of after-riDenine. The 



seem 



process of after-ripening then is interesting in that it does not obey 
the van't Hoff 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 w T hole 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- 



oxy 



sufficient 



certainly favors after-ripening. We ai 
ments to determine more definitely the 
to after-ripening and oxygen pressure. 



hawthorn 



seem 



to enter into the after-ripening of the 
sat At the optimum temperature after- 



6o BOTANICAL GAZETTE [July 



ripening goes on equally well in dark or light. At a temperatu 



imum, but not sufficiently 



some 



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 



immediately 



more 



hyp 



than in the cotyledons or any of the external structures. 



1912] DAVIS & ROSE— AFTER-RIPENING 6 1 



removed from the carpels 



and at a temperature of 5 or 6 



may 



months, and if the testas are removed 



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 
be 5 °-6 




Low temperatures alternating with high temperatures 
favorable for after-ripening. 



/ 



removed from the cold chamber 



j have passed through the after-ripening period and subjected to the 
I temperature of the greenhouse, the high temperature either stops 
V or greatly retards the process of after-ripening. 






I quickly. T 
\ germination. 



ids are completely after-ripened and removed from 
temperature of the greenhouse, they germinate a 
le hierh temperature erreatlv stimulates the proces 



After-ripening readily takes place under ordinary oxygen pres- 



determined 



may be 




The pulp, carpels, and seed coat itself tend to delay the process 



by 




mbry 



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. 

The 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. 

2. , Longevity of seeds. Box. Gaz. 47:69-72, 1909. 

3. Cyclopedia 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 Keimungsbedingungen einiger siidamerikanischer 

Gramineen-Samen. Ber. Deutsch. Bot. Gesells. 28:350-364. 1910. 

7. , Ueber Keimungsbedingungen einiger siidamerikanischer 

Gramineen-Samen. Ber. Deutsch. Bot. Gesells. 28:504-512. 1910. 

8- Heinricher, E., Beeinflussung der Samenkeimung durch das Licht. 

Wiesner Festschrift. Wien. 1908. 
9. , Die Samenkeimung und das Licht. Ber. Deutsch. Bot. Gesells. 

26a: 298-301. 1908. 
10. , Keimung von Phacelia tanacetifolia Benth. und das Licht. Bot. 

Zeit. 67:45-66. 1909. 
11- Kinzel, W., Die Wirkung des Lichtes auf die Keimung. Ber. Deutsch. 

Bot. Gesells. 26a:io5~ii5. 1908. 
12. , Lichtkeimung; Erlauterungen und Erganzungen. Ber. Deutsch. 

Bot. Gesells. 27:536-545. 1909. 
13* , Ueber die Keimung halbreifer und reifer Samen der Gattung 

1 

Cuscuta. Landw. Versuchs. Stat. 54:133. 1900. 

14. Kuntze, Richard E., Germination and vitality of seeds. Mem. Torr. 
Bot. Club. 1901. 

15. MullerK., See Pfeffer's Physiology of plants. Englished. 1:210.1903. 

16. Nobbe, F., and Hanlein, H., Ueber die Resistenz von Samen gegen die 
ausseren Factoren der Keimung. Landw. Versuchs. -Stat. 20: 71-96. 1877- 

17. Pammel, L. H., and Lummis, G. M., The germination of weed seeds. 
Ames, la. 1903. 

18. Pammel, L. H., and King, Charlotte M., Results of seed investigations 
for 1908 and 1909. Bull. 115. Ames, la. 1910. 



THE STRUCTURE OF THE STOMATA OF CERTAIN 

CRETACEOUS CONIFERS 1 

W. P. Thompson 

(WITH PLATES V AND Vl) 

The structure of the stoma is remarkably uniform in all members 
the plant kingdom, from Anthoceros to the highest angiosperms. 
consists essentially of an aperture surrounded by two guard 
tfhich may be more or less sunken and protected by adjacent 



cells. 



from 



more 



for the fossil genus Frenelopsis, first by Zeiller, 2 and 
by Berry. 3 These authors state that in place of th>e 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 

■ m 

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 
Choffat. 

The characters of the genus Frenelopsis have been given in 
detail by Ettingshausen, 4 Schenk, 5 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 the jointed 
stem. They are reduced, squamiform, and appressed. The inter- 
nodes functioned as leaves. 

The epidermal characters of Frenelopsis occidentalis have been 

x Contributions from the Phanerogamic Laboratory of Harvard University* 
No. 45. 

2 Zeiller, R., Observations sur quelques cuticules fossiles. Ann. Sci. Nat. Bot. 
6: i3- 1882. 

3 Berry, E. W., The epidermal characters of Frenelopsis ramosissima. Bot. 
Ga * 50:305-309. figs 2. 1910. 



4 Ettingshausen, C, Abhand. k.k. geol. Reichsanstalt. Vol. I. 

5 Schenk, H., Palaeontogr. 19:13. — . 



63 



[Botanical Gazette, vol. 54 



64 BOTANICAL GAZETTE [july 



described by Zeiller. 6 The cells are rather small, roughly 
rectangular, and very thick- walled. The very numerous stoma ta 
are arranged in irregular lines which give a striated appearance 

to the unmagnified specimen. 

A single stoma is shown in surface view in fig. i. 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 
particuliere des stomates, serait celui qu'on observe chez les Marchantiees, oil 
les pores stomatiques sont bordes par cinq ou six cellules, mais qui laissent 
entre elles une ouverture en forme de canal, et non pas une fente en etoile* 



comme dans l'espece dont je viens de parler. 



Lguli 



et assez peu vraisemblable que cette forme etoilee des stomates fut un fait 
isole, n'existant que chez le seul Frenelopsis Hoheneggeri, et peut-etre faut-u 
s'attendre a la retrouver quelque jour sur d'autres plantes fossiles, sinon meme 
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. 7 Aside from their unique number and disposi- 

6 Zeiller, R., Elements de palaeobotanique. Paris. 1900. 

7 Loc. cit., p. 307. 



i9i 2] THOMPSON— STOM ATA 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 bomensis 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 
jour in number surrounding the opening. From the same view- 
Point, the guard cells (fig. 8) are seen to be two in number, and 
arranged in the usual manner. 



of Frenclopsis are really accessory cell: 
below them for the true guard cells. As 



guard 
must 



that 



materi 



are not likely to have been preserved. 



man y 



able specimens. Fig. 3, which is a photograph of another stoma 
m 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 
ce lls. 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 
guard 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 



more difficult to observe the guard 



Vl ew, 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 



ermis from beneath 



some instances, and of lm 



many others- A camera lucida drawing showing their typical 
angement above the accessory cells (below in nature) is presented 

Thev are seen to have the normal form. The thinness 



in fig. 5. 



1m 



tion. 



of the normal form 



lopsis, in addition to the remarkable accessory cells, is further 
indicated by the similar conditions presented by other cretaceous 



plants. A case in 
Hollick and Jeffrey 



is furnished by Androvettia statenensts 
. 9 is a photograph showing the general 
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 



ermis 



ma 



of accessory cells around the stomata as before. In this case they 
lack the conical projections of Frenelopsis, the opening having a 
uniform outline. The presence of true guard cells is strikingly 



figu 



across 



irrounded 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, in 
poorly preserved specimens they have often been destroyed just 
as in Frenelopsis. Fig. 1 1 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. A section 
parallel to the surface of the leaf of this plant is shown in fig- i 2 - 
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 m 
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 









4 









THOMPSON on STOMA I A 




BOTANICAL GAZETTE, LIV 



PLATE VI 










10 






THOMPSON on STOMATA 



12 



iqi2] 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 

Fig. 1. — Frenelopsis Occident alls: stoma in surface view, showing the 
rosette of projections; X333. 

Fig. 2. — The same: vertical section through a stoma, showing the pro- 
jections into stomatal cavity; X250. 



Fig. 3. 



guard 



accessory cells; X250. 



Fig. 4. — The same: another stoma with distinct guard cells; X 250. 

Fig. 5. — The same: camera lucida drawing of stoma from beneath, show- 

:wo guard cells above the accessory cells. 

Fig. 6. — Agathis bornensis: vertical section of base of leaf, showing two 



guard cells sunken 



X333- 



Fig. 7.— The same: section parallel to the surface, showing stomatal 
opening surrounded by four accessory cells; X333- 

Fig. 8.— The same: section parallel to the last but deeper— below the 
accessory cells and including the two guard cells; X333- 

Fig. 9. — Androvettia statenensis: surface view of epidermis; X63. 



Fig. 



10. 



guard 



accessory cells; X250. 



Fig. 



11. 



guard cells have disappeared 



X250. 



Fig. 12.— Br achy phyllum macrocarpitm: section parallel to the surface, 
I accessory and guard cells; X125. 



BRIEFER ARTICLES 



EDUARD STRASBURGER 1 

(Born February i, 1844; died May 19, 191 2) 

(with two portraits) 

In the death of Strasburger, 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 
1 an attack of heart disease. 
I Strasburger was a native 

I of Russian Poland, and began 

his education at Warsaw, study- 

| ing later at Bonn and at Jena. 

r He traveled extensively in 

' Europe, and in 1873, with 
Haeckel, 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 family, was proud of his children, and during the long 
period while Mrs. Strasburger 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 

x An account of Stras burger's laboratory and work, written by Professor 
J. E. Humphrey, was published in this journal eighteen years ago (Bot. Gaz. 19"- 
401-405, with portrait. 1894). 

Botanical Gazette, vol. 54] 68 



1912] 



BRIEFER ARTICLES 



69 



1 



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 embryology 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 recognized as the most 

mportant cytological center in . eaa ^^^ 

the world. 



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 

plants, and every 






/ 



' 




flowering 




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 
day 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 h 



our or more. 



particul 



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- 
ence will be of more interest than anything else one could write. In a 
letter of June 20, 1010, he savs: "I prize very highly the kindly recogni- 



70 BOTANICAL GAZETTE [july 

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 



in 



responsible for it." 

Of 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. 



flux 



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 



Hermann Schacht 



Julius 



time 



The sudden 



Schacht made me decide to go to Jena to Pringsheim 
\ visits to Schacht, and who invited me to become his a 
\ind of Pringsheim reacted beneficially upon me, while i 
*st Haeckel soon made me enthusiastic over the greal 



The 



sented by Charles Darwin. 

My acquaintance with my ten years older teacher soon became friendship, 
and I have to thank Ernst Haeckel 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 Hofmeister. Unfortunately, during 
the latter part of his life, Hofmeister became very sensitive and was angry 
with me because in 1869 in my work on Befruchtung bei den Conifer en I sought 
to prove that the "corpuscula" do not correspond to the embryo sacs of angio- 
sperms, but are archegonia. Hanstein came to Bonn as professor after I had 
already settled in Jena. In 1887 I came to Bonn as Hanstein's successor. I 



J 



very 



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. 



IQI2] 



BRIEFER ARTICLES 



71 



tv 









1> 




r 










/ 














/ 




J 








J 















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 role of the nucleus in fertilization and 



Winkler 



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 
prune 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, 191 1, 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. 

j 













a: 








J. Chamberlain, The University of 



CURRENT LITERATURE 



BOOK REVIEWS 
The Chicago textbook 1 

Of the three parts composing the Chicago Textbook of Botany for Colleges 

and Universities, "Morphology" by Coulter and "Physiology" by Barnes 

appeared nearly two years ago, and were noticed in this journal 2 , while 

'Ecology" by Cowles, 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 ? In 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, 



Barnes 



Vol. II. Ecology. 



ovo, pp. 480. figs. 5?*. New York: American Book Co., 191 2. $2.00. 



Bot. Gaz. 51:67. ion. 



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. 950), the author attempts to 
avoid all such expressions, visiting with especial condemnation anything of 
teleological implication. But only a bogey of his 
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" 
(P- 487) f 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 



own 



1m 



tion, at the top of p. 950. 



rything 



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. Ganong. 



An elementary text 



A new elementary text by Bergen and Caldwell 3 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 



very 



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 



imaginary 
of "fads." 



The book before us has been handicapped in setting the task of meeting 



time 



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 
m obscurity. In spite of the divergent purposes and space limitations, the 
book is a marked advance in the direction intended. 



ntroductory 



(PP 



mentary forestry (pp. 21); plant breeding (pp. 21); plant industries (pp. 30); 
weeds (pp. n); 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 



(pp. 156-370) 



elementary 



elementary 



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 

3 Bergen, J. Y., and Caldwell, O. W., Practical botany, pp. v+545- fii 5 - i 5x * 
Boston: Ginn & Co., 1911. 



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 Hancock's Nature 

Sketches 4 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, by drawings, photographs, and colored plates 
of examples from temperate America. The adaptations of insects, birds, and 
flowers are discussed, and the author 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. 5 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. 



Popular manuals.— The nature and purpose of the very interesting 
Cambridge manuals of science and literature have been noticed in this journal. 6 
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. Seward (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 
resume of current scientific knowledge. The titles of the eight chapters of 
Professor Seward's volume will give a better conception of the contents than 
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 



jj 



>>. 



4 Hancock, Joseph L., Nature sketches in temperate America. 8vo. xviii+45 1 
pis. 12. figs. 215. Chicago: A. C. McClurg & Co. 1911. $2. 75. 

s Pearse, in Science 34-37- 1912, is mistaken in this matter. 
6 Bot. Gaz. 52:234. 191 1. 



1912] CURRENT LITERATURE 77 



"The maiden hair tree." The American publisher is G. P. Putnam's Sons 
of New York. — J. M. C. 

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 (1), and Xenodochus (1). 

J. M. Greenman. 



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. 

Vogler 8 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 Klebs 9 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 



every 



vincing 



7 North American flora. Vol. VII, part 3, pp. 161-268. The New York 
Botanical Garden. April 15, 1912. 

8 Vogler, P., Variation der Anzahl der Strahlbluten bei einigen Kompositen. 
Beih. Bot. Centralbl. 25:387-396. 1910. 

9 Klebs, 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, 5, 8, 13, 
etc., and low multiples of them, or on the similarly constituted "Trientalis- 
series," 3, 4, 7, n, etc., and their low multiples. The latter series was dis- 
covered by Ludwig in Trientalis, whence its name. Vogler 10 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 11 has reported on the number of ray flowers in 
Arnica montana, Buphthalmum solid folium, 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 1 1 and only a slight indication of a mode on 1 3 . 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 12 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 saliva, 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 io|/T, ioi/"2, 101/J, ioi/"s, 101/8, etc., 



10 Vogler, P., Variationstatistische Untersuchungen an den Dolden von Astrantia 
major. Beih. Bot. Centralbl. 24: 1-9. figs. 6. 1908. 

"Vogler, P., Neue variationstatistische Untersuchungen an Compositen. 



Naturwis 



12 Ritter, G., Uber d; 
Centralbl. 25:1-29. 1909. 



Beih. Bot. 



i9 1 2] 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 1 ^ shows by a much more extensive series of measurements of leaflets 
of Cytisits 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 1 * 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. 

De Bruyker 1 * 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 16 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 



Vogler 



Beih. 



Bot. Centralbl. 27:391-437. figs. 12. 191 1. 

14 Volger, P., Probleme und Resultate variationstatistischer Untersuchungen an 
Bluten und Bliitenstanden. Jahrb. St. Gallischen Naturwis. Geseils. 1910:33-71. 
1911. 

15 De Bruyker, 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. 1910. 

16 Johannsen. W. t Elemente der exakten Erblichkeitslehre. pp. vi+516. figs. 31. 
Jena: Gustav Fischer. 1909. 



8o BOTANICAL GAZETTE [July 



season, which attributes it to a change of nutrition, an interpretation which was 
given independently by MacLeod 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 w T hich each succeeding group of organs added is 
related to the preceding group or groups. 

De 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, 20, 
etc.), as in the number of stamens in Pyrus communis; (e) the Fibonacci- 
Ludwig series (1, 2, 3, 5, 8, [10], 13, [16], etc.), as in many Compositae, Umbel- 
liferae, etc.; (J) 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 Vogler for the number 
of flowers in Cardamine pratensis; (h) the odd series (1, 3, 5, 7, 9, etc.), 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. De Bruyker'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 100 papers dealing with the subject 
of variation and its statistical study, and a full index is added. 

Nieuwenhuis 17 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 18 in Aster 



v Nieuwenhuis, M., Die Periodicitat in der Ausbildung der Strahibluten bei den 
Kompositen. Recueil Trav. Bot. Neerl. 8: 1 08-181. figs. 23. 191 1. 

18 Shull, G. H., Place-constants for Aster prenanthoides. Box. Gaz. 38: 333~375 • 



1904 



1912] CURRENT LITERATURE 8l 



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 divaricatitm 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, Dimorphotheca pluvialis, Laya platyglossa, and 
Sanvitalia procumbens, the plants grown from the two kinds of seeds produced 
essentially like variation curves. The same thing was true of plants grown in 
different 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. Shull. 



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 
roots. 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 Hill 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 Solms-Laubach 1 * with 
convincing results. He worked cheifly with thin sections of fossils (P. H a id in- 
geri) from Manebach, supplemented by material from the Museum of Rio 



19 Solms-Laubach, H. Grafex zu, Der tiefschwarze Psaronius Haidhtgeri von 
Manebach in Thuringen. 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 tissue 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 
the hairs of the stem fill the crevices between the first roots and are soon over- 
grown 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 be detected. No branch- 
ing of the filling tissues appears, because of the constant correspondence between 
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; and a 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 peculiar development of the outer cortex 
is present in plants related to Psaronius, Solms-Laubach examined a stem of 
Xylo psaronius. 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 
resemblance. In confirmation of this, Schuster 20 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 Solms-Laubach. His photomicrograph of 

20 Schuster, J., Xylopsaronius, der erste Farn mit secundarem Holz ? Ber. 
Deutsch. Bot. Gesells. 29:545-548. 1911. 



19"] 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 confluens. — Believing that the alterna- 
tion of generations has not yet been satisfactorily worked out in any fungus, 
Claussen 21 has completed an extensive cytological and morphological study 
of the development of Pyronema confluens, a form already investigated by 
Harper 22 . 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 2 * 
and of Kjhlman. 2 ** 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 sexual 
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 



21 



Claussen, P., Zur Entwicklungsgeschichte der Ascomyceten. Pyronema 



confluens. Zeitschr. Bot. 4: 1-64. pis. 6. figs. 13. 1912. 



22 



Harper, R. A., Sexual reproduction in Pyronema confluens and the morphology 



of the ascocarp. Ann. Botany 14:321-400. 1905. 

23 De Bary, A., Ueber die Fruchtentwicklung der Ascomyceten. Leipzig. 1863. 
34 Kihlman, O., Zur Entwicklungsgeschichte der 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 25 holds that there is no fusion of the 
sexual 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 
divisions is about twelve. The process of spore formation and spore delimi- 
tation is essentially as described by Harper. 

According to Claussen, the spore, mycelium, and sexual organs constitute 
the gametophyte, while the ascogenous hyphae represent a sporophyte not 
sharply 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 



ntroductory account 

a number of forms 

; of the morphology 



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, 

In Amorphomyces alone the septum is not 
es. The cells of the thallus are character- 



dividing the spore into two cells, 
formed and the nucleus deerenera 



istically uninucleate, but after the thallus has completed its growth some of the 



2 s Brown, W. H., Nuclear phenomena in Pyronema confluens. Johns Hopkins 



Univ. Circ. 6:42-45. 1909. 



4 



26 Faul, J. H., The cytology of the Laboulbeniales. Ann. Botany 25:649-654 



1911 



19"] 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 described. 

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 



sexu 



a comparison of a dioicous species, Br yum caespiticium, with a number of synoi- 
cous species, chief among which is Amblystegium serpens. In the dioicous 
species one-half of the spores give rise to protonemata which produce antheridial 
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 

27 Marchal, El., La sexualite 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 
cells. 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. 

Marchal is able to induce apospory in the capsule of Bryum caespiticiutn. 
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 game to- 
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 subtile, 
Barbula muralis, and many others which the author does not name. He states 
that Ephemerum serratum and Funaria hygrometrica are synoicous. Miss 
Speer, working in the Hull Botanical Laboratory, first showed that the latter 
species is occasionally synoicous. Marchal is at present studying a sterile 
synoicous Bryum 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. — Schwartz, who has recently made several contribu- 
tions to our knowledge of the parasitic slime molds, gives an account 28 
of another form which he found on the roots of Poa annua and other grasses. 
The organism, to which he gives the name Soros phaera 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 eehvorms. 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 Schwartz, E. J., The life-history and cytology of Sorophaera graminis. Ann. 
Botany 23:792-797. 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. These undergo 
mitotic divisions, after which the Plasmodium is broken up by cleavage into 
small uninucleate masses which become the spores. Under the classification 
of Maire 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. — Scott 2 * 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 interpretation 
of the pithlike region with interspersed tracheids than to regard the cylinder 
as a " condensed" polys telic structure. It would be even simpler to eliminate 
"highly elaborated," and to call the cylinder an incomplete protostele. The 
problematical and abundant "aphlebiae" are found to be "modified basal 



shown bv the structure 



strand."— J. M 



Effect of temperature on respiration. — Kuijper, 30 while at the Buitenzorg 
laboratories, determined the C0 2 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. 31 But the "critical temperature" 
(temperature at which a high respiratory intensity is maintained for a con- 
siderable time) of Arachis hypogaea is 5°-io° higher than that previously found 
for Pimm and Lupinus. Kuijper thinks this difference is due to their sur- 



roundings. 



J 



temperature of the vegetation period of the temperate zone. — Sophia H. 
Eckerson. 



29 Scott, D. H., On a paleozoic fern, the Zygopteris Grayi of Williamson. Ann. 
Botany 26:39-69. ph. 1-5. fig. 1. 191 2. 

30 Kuijper, J., Einige weiteren Versuche iiber den Einfluss der Temperatur auf 
die Atmung der hoheren Pflanzen. Ann. Jard. Bot. Buitenzorg II. 9*45-54- P^- 6, f* 



1911. 



31 Bot. Gaz. 50:233. 1910. 



88 BOTANICAL GAZETTE [july 






Doubling of embryo sac. — Compton 32 reports an interesting situation in 
a Lychnis hybrid, in which an ovule contained two embryo sacs, each pene- 
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. 

Seedling structure of Centrospermae. — Hill and DeFraine^ have 
recorded 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. C. 

Fall of leaves. — Based upon a mass of data collected largely from 
the literature, Combes** shows that the conception of Sachs 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 percentage of substances that would have 
been utilizable by the plant. — Chas. O. Appleman. 

Morphology of Viola. — Miss Bliss** 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- 
fertilization structures of the sac are what may be regarded as normal for 
angiosperms. Double fertilization was observed in V. cucullata. "There 
is no suggestion of a suspensor," and the embryo, surrounded by a solid mass 
of endosperm, is bright green.— J. M. C. 



* Compton, R. H., Note on a case of doubling of embryo sac, pollen tube, and 
embryo. Ann. Botany 26: 243, 244. 1912. 

33 Hill, T. G., and DeFraine, Ethel. On the seedling structure of certain 



rm 



Ann. Botany 26:175-199. figs. 15. 1912. 



w Combes, Raout, Les opinions actuelles sur les phenomenes physiologiques qui 
accompagnent la chute des feuilles. Rev. Gen. Bot. 23:129-264. 1911. 

35 Bliss, Mary C, A contribution to the life history of Viola. Ann. Botany 

26:155-163. pls.iy-ig. 1912. 
\ 



LIV 



No. 2 



THE 





August 1912 



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 



The University of Chicago Press 



CHICAGO, ILLINOIS 



Agents 
AMBR1DGE UNIVERSITY PRESS, London and Edinburgh 

WILLIAM WESLEY & SON, London 

T*L STAUFFER, Leipzig 
MARUZEN KABUSHIKi -KAISHA. Tokyo. Otoka, Kyoto 



Gbe Botanical (5a3ette 

a dfcontbtB Journal Embracing all Departments ot UBotanfcal Science 

Edited by John M. Coulter, with the assistance of other members of the botanical staff of the 

University of Chicago. 

Issued August J6, 1912 



Vol, LIV CONTENTS FOR AUGUST J9J2 No. 2 



SPERMATOGENESIS IX EQUISETUM. Contributions from the Hill Botanical Labora- 
tory 158 (with plates vii and viii). Lester W. Sharp ------- 

THE PRIMARY COLOR-FACTORS OF LYCHNIS AND COLOR- INHIBITORS OF PAPA- 

VER RHOEAS. George Harrison Skull - - 

CONTRIBUTIONS FROM THE ROCKY MOUNTAIN HEBARIUM. XI (with two fkires). 

Aven Nelson -------------- 

BENEFICIAL EFFECT OF CREATININE AND CREATINE ON GROWTH (with one 

figure). /. /. Skinner ------ -- 

BRIEFER ARTICLES 



89 



120 



136 



152 



A Note ox the Generations of Polysiph* r\ (with one figure). George B. Rigs and 

Annie D. Dalgity ------- - ..---- 164 



CURRENT LITERATURE 

BOOK REVIEWS 

lOREST PHi [OGRAPHY. A YOSEMITE FLORA 

NOTES FOR STUDENTS - - - - 



166 



.♦ 



168 



■- 



The Botanical Gazette is published monthly, * The subscription price is 7.00 per year; the price 
of single copies is 75 cents. ^Postage is prepaid by the publishers on all orders from the United States, 
Mexico, Cuba, Porto Rico, Panama Canal Zone, Republic of Panama, Hawaiian Islands, Philippine 
Islands kam, Tutuila (Samoa), Shanghai. ^[Postage ia charged extra as follows : For Canada, 35 cents 
on annual subscriptions (total $7.35), on single copies, 3 cents (total 78 cents); for all other countries in the 
Postal Union, 84 cents on annual subscriptions (total $7.84), on single copies, II cents (total 86 cents). 
^Remittances should be made payable to The University of Chicago Press, and should be in Chicago or 
New York exchange, postal or express money order. If local check is used, 10 cents must- be added tor 
collection. 

The following agents have been appointed and are authorized to quote the prices indicated : 

For the British Empire: The Cambridge University Press, Fetter Lane, London, E.C., and William 
Wesley & Son, 2 sex Street, Strand, London Yearly subscriptions, h (tiding postage, £1 125. 6«. 

each; single copies, including postage, 3^. 6</. each. 

For the Continent of Europe: Th. Stauffer, Universitatsstrasse 26, Leipzig, Germany. Yearly sub- 
scriptions, including postage, M. 33 each: single copies, including postage, M. 3.60 each. 

For Japan and Korea: The Maruzen-Kabushiki-Kaisha, 1 1 to 16 Nihonbashi Tori Sanchome, Tokyo* 
Japan. Yearly subscriptions, including postage, Yen 15.75 each; single copies, including postage, Ven 
1.75 each. 

Claims for missing numbers should be made within the month following the regular month of publi- 
cation- The publishers expect to supply missing numbers free only when they have been lost in transit. 

Business correspondence uld be addressed to The University of Chicago Press, Chicago, 111. 

Communications for the editor should be addressed to him at The Ur> ersity of Chicago, Chicago, JU* 

Contributors are reqi sted to write scientific and proper names with particular care, to use the metric 
system of weigh! i measures, and in cita Oiu to follow the form wn in the pages of the B« * ICA • 

Gazette. 

Papers in exce of thirtv-tw printed pages are not accepted- unless the author U willing to P 9 ?}'? 
cost of the ad tional pages, in w ch case the number of pages in the volume is correspondingly increase 

Illustrations are furnished without c t I author on: when su le ari naJs are supplied. A coj 
of the suggestions made in the January number, 1007, \ U be sent on application. It is advie >ie 
confer with the editors as to illus ions required 1 any ai le to be offered. . . j 

Separates, if desired, must be ordered 1 advance" of publico Twenty-five separates of origin 

articles without covers will be supplied gra* , A table owing at roximatt f additional separate 

is printed on an order blank which accompanies the proof; a c py will be sent on request. 

Entered August 2t, 1896, at the Post-office at Chicago. $ second-class matter, under Act of Congrress March 3, * 3 79* 



VOLUME LIV 



NUMBER 2 



THE 



Botanical Gazette 



AUGUST 19 1 2 



SPERMATOGENESIS IN EQUISETUM 

CONTRIBUTIONS FROM THE HULL BOTANICAL LABORATORY 1 58 

Lester W. Sharp 

(WITH PLATES VII AND VIIl) 

Historical resume 

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 Mutidstclle. 
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 Uautschicht organs in the algae, and that 
all of them are morphologically distinct from centrosomes. 

Daxgeard (17) found a deeply staining granule at the base of 
the cilia in Chlorogoniunu but did not consider it a centrosome. In 

89 



90 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 Belajeff (2) and by Mottier (71). Here the 



blepharoplast arises as a differentiation of the plasma membrane 
and bears two cilia. No centrosomes or Plasmahbcker were 
observed at the base of the cilia, although Schottlander (75) had 
previously reported centrosomes in the cells of the spermatogenous 

» 

filament. 

Griggs (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 Jahn (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 



i9 1 2] SHARP— SPERMATOGENESIS IX EQUISETUM 91 

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 
pteridophytes and gymnosperms are derived ontogenetically or 
phylogenetically from centrosomes, but that all bodies called centro- 
somes in plants may not be homologous. In a paper appearing 
two years later, Miyake (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 9 s centrosome is present, except 
at the last mitosis, when a bodv lies at each soindle Dole as figured 



by that author. 



the same resuJ 
Makinoa. Miy 



centrosome hitherto reported in the cells of the Hepaticae is nothing 
but a center of cytoplasmic radiation, and inclines toward the view 



homologous structures. 



centrosome 



Mar chant 



.permatid 



cell in contact with the plasma membrane. These occupy the 
spindle poles and in the spermatids function as blepharoplasts. 
Escoyez 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 (6i) reports centrosome-like 
structures in the early and diagonal divisions. These apparently 



asm 



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- 



92 BOTANICAL GAZETTE [august 

phytes are embodied in two papers appearing in 191 1. In the 
first of these Woodburn (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 Mot- 
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 
Mniunt. 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 Atrichum the 
first body separated from the nucleolus becomes the blepharoplast, 
a second forms the limosphere, and a third the accessory body. In 
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. Wilson regards the blepharo- 
plast as " probably derived from a centrosome." 

According to Humphrey (49) the blepharoplast of Fossombronia 
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 (i), 
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- 



i9"] 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 Char a, ferns, and Equi- 
setum. In all of these forms a small body elongates to form a 
thread upon which small Hdcker arise and grow out into cilia. 
In a comparison with animal spermatogenesis, Belajeff here 
homologizes the Korperchen (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 Gymno gramme 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. Belajeff 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 Hirase (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. Fujn (30, 31, 32) gave several figures of spermatogenesis 
in Ginkgo, which agree with the accounts of Hirase and 
Webber. The same subject has been dealt with more recently 
by Miyake (67). 

In two short papers appearing in 1897, 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—SPERM ATOGENESIS 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 



form 



manner similar 



Several years later the same writer published two papers 



m 



In 



former 



makes comparisons with analogous phenomena in animals, which 
he believes sustain the homologies of Belajeff. 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 BleoharoDlast" in the development 



spermatid into a spermatozoid. The Hautsch 



& 



algae are also held to be ontogenetically or phylogenetically derived 
from centrosomes. In the later contribution (55) he insists less 



strongly upon the mo 



them into three categ 



itity of all blepharoplasts, 
(1) centrosomatic blepharo- 



plasts, including those of the myxomycetes, bryophytes, ptendo- 
phytes, and gymnosperms ; (2) plasmodermal blepharoplasts, those 
of Char a and some Chlorophyceae; (3) nuclear blepharoplasts, 
found only in a few flagellates. 

The blepharoplasts of Microcycas (Caldwell ii) 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 

of two of the original black granules. Very 



enlargement 



mitosis 



form the cilia-bearing band as in other cycads. In an earlier 



homolo 



centrosome 



From 



two general views concerning the morphological nature of the 



gymno 



sperms 



(i) The blepharoplast represents a centrosome (Hirase 



GuiGNARD, SCHAFFNER, WlLSON 



asmic 



material but not a centrosome (Strasburger, Webber, Shaw, 



Woodburn). 

spermatogene 



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 90 CC., freshly 
distilled neutral formalin 



10 cc. 



Description 



theridium 



that it occurs in two forms, developing in some cases like the anthe- 
ridium of the eusporangiate DteridoDhvtes. and in others from a 



igi2] SHARP— SPERMATOGENESIS IN EQUISETUM 97 



papillate cell as in the Filicales. The mode of development has 
usually been correlated with the position of the antheridium 
initial in the pro thallium. 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 

stakably of the latter form. Apparently any * 



unm 



prothallium 



able to divide periclinally and produce antheridia of the well known 
imbedded type. 



chromatin 



form 



£> 



accumulated 



more 



asm 



conspicuous nucleoli are present. The cytop 
cell generations may contain many plastids in various stages of 
disorganization; 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 libers 



without 



somes 



indication of approaching sperm 



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 

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 



the 



sperms are mature 



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 0.5/4. 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- 



iqi2] 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 



ioo BOTANICAL GAZETTE [august 



weak in development, so that the relation it bears to the blepharo- 



determined at this time. There is no 



question , however, that the blepharoplasts continue to occupy the 



lmme- 
many 



diately preceding stages. In the later stages of division 
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 

was not determined. The cell 



asm 



sperm 



During the anaphases of karyokinesis a peculiar change occurs 
in the blepharoplasts. For a time they lose their affinity for iron- 



many 



may 



more 



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- 

erial. 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 



ma 



form 



i 



7, 18). 



hich 



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 Drobable that a* a mlp parh crrarmle gives rise 



1912] SHARP— SPERMATOGENESIS IN EQUISETUM 101 



to one cilium. The further details of cilium development were not 

i 

worked out. 

The blepharoplast granules, which 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- 2 3)- At this stage the nucleus and the blepharoplast lie rather 
close together; the relative position of the two is seen in fig. 24, 



similar cell viewed from 



tion a. 



assumes 



form, while its reticulum becomes 



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 



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 
tigs. 28 and 29. The nucleus now stains intensely with iron- 
hematoxylin. Its surface presents a mottled appearance while 
rery lightly stained sections show that its interior is quite homo- 



\ 



with several verv small 



mos 



the 



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 M. 



Discussion 



morph 



Strasburger, Webber 



that 



reference to the additional evidence afforded by Equisetum without 
risk, or even necessity, of a certain amount of repetition. In the 
foregoing historical resume 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 



phenomena 



spermato 



centrosomes 



covered by Butschli (10) in the diatom Surirella. It had earlier 
been seen by Smith (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. 



igi2] 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), Humphrey (48), and Swingle (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. Strasburger (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. Mottier (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 Mottier. He also states that the entrance of the sperm causes 
a centrosome with radiations to appear in the egg cytoplasm. 



104 BOTANICAL GAZETTE Iaugust 



Wolfe (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, P hyllactinia , 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 Maire (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. Faull (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 






i9i 2] SHARP— SPERMATOGENESIS IN EQUISETUM 105 



(73) 



lie was not made out in these three forms. According to Sands 
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 



mov 



and establish the spindle in the usual way. Centrosomes 



figured 



In 



raser and Welsford 



centrosomes and asters. The figu 
that division of the centrosome occi 



centrosomes 



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 Hook (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 Berghs (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 



io6 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 known 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 



igi2] SHARP— SPERMATOGENESIS IN EQUISETUM 107 

arrange themselves in a row and coalesce to form the cilia-bearing 
band. 



nomena 



evident. Although limited to a single mitosis 



most 



centrosome 



metamorph 



In thus combin- 



main characteristics of true centrosomes 



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 



foreshadow 



marked 



To the present writer 



seem 



Iken 



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 



rmer 



centrosome nature. He Doints out that it differs from 



true 



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 are concerned, and in its behavior 
in fertilization. Although the blepharoplasts of other plant groups 



must 



formulated largely through a consideration of the cycad situation. 
W hen the blepharoplast is regarded as an organ developing pro- 



gressiv 



gvmnosperms 



io8 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 
Korff (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 Meves and 
Korff are strikingly like those of Ginkgo (Hirase) 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 



igia] SHARP— SPERMATOGENESIS IN EQUISETUM 109 



centrosome 



cc 



rudiments" 



spermatogenous cells of Marsilia 



certain liverworts are so remarkably centrosome-like. Moreover, 
many true centrosomes appear de novo in each successive cell genera- 



mitosis 



elimi 



from 



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. Webber'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 Woodburn (95) believes it 
does in certain liverworts. Belajeff's view concerning the pres- 
ence of these structures only in the spermatogenous cells is that 
every cell has its definite "dynamic center," butonly in these cases 
is a 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 (Korff 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 distinguish 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, 



no 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 role 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. 



igi2] SHARP— SPERMATOGENESIS IN EQUISETUM III 



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 blepharoplast s." 

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), Korff (58), 
Patjlmier (72), and several others have established beyond ques- 
tion the fact that the centrosome (or centrosomes) of the animal 
spermatid plays an important role in the formation of the motor 
apparatus of the spermatozoon, the axial filament of the nagellum 



112 BOTANICAL GAZETTE [august 



growing out directly from it. Henneguy (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 (Korff 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. Wilson (92) regards the work of Shaw and 
Belajeff on Marsilia as establishing beyond question the identity 
x>{ 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 agrees 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 Studnicka (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 






igi2] 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 

mitoses in the spermatogenous tissue of Equi- 
centrosomes, centrosoheres, or asters. 



minute 



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. 



form 



membrane 



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 
the cilia-bearing thread. 



form 



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 Equisetum y 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 
ontogeneticallv or Dhvloseneticallv from centrosomes. 



H4 BOTANICAL GAZETTE . [august 



The investigation here recorded was carried on under the direc- 

tion of Professor John M. Coulter, 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 
Yamanouchi for many helpful suggestions. 

The University of Chicago 



LITERATURE CITED 

1. Belajeff, W., Ueber Bau und Entwickelung der Spermatozoiden der 
Gefasskryptogamen. Ber. Deutsch. Bot. Gesells. 7:122-125. 1888. 

2. , Ueber Bau und Entwickelung der Spermatozoiden der Pflanzen. 

Flora 7Q:Erganzab.:i-48. pi. 1/ 1894. 

3. , Ueber den Nebenkern in spermatogenen Zellen und die Spermato- 

genese bei den Farnkrautern. Ber. Deutsch. Bot. Gesells. i5 : 337~339- 
1897. 

4. , Ueber die Spermatogenese bei den Schachtelhalmen. Idem 15 : 339"" 

342. 1897. 

5. , Ueber die Aehnlichkeit einiger Erscheinungen in der Spermato- 
genese bei Thieren und Pflanzen. Idem 15:342-345. 1897. 

6. , Ueber die Cilienbildner in den spermatogenen Zellen. Idem 

16:140-144. pi. 7. 1898. 

7- , Ueber die Centrosome in den spermatogenen Zellen. Idem 

17:199-205. pi. 13. 1899. 

8. Bolleter, E., Fegatella (L.) corda. Eine morphologisch-physiologische 

Monographic. Beih. Bot. Centralbl. 18:327-408. pis. 12, 13. i9°5- 

9. Buchtien, O., Entwicklungsgeschichte des Prothalliums von Equisetum. 
Bibliotheca Botanica 8:1-49. pis- x ~6. 1887. 

10. Butschli, O., Ueber die sogenannten Centralkorper der Zelle und ihre 
Bedeutung. Verhandl. des Naturhist.-Med. Vereins zu Heidelberg. N.F. 
4:535-538. 1891. 

11. Caldwell, O. W., Microcycas calocoma. Bot. Gaz. 44:118-141- P^- 



10-13 
Campi 



der Spermatozoiden 



Ber. Deutsch. Bot. Gesells. 5:120-127. pi. 6. 1887. 
13. Chamberlain, C. J., The homology of the blepharoplast. Bot. Gaz. 
26:431-435. 1898. 

14* , Mitosis in Pellia. Decennial Publ. Univ. of Chicago 10:329-345- 

pis. 2 5-2 7. 1903. 
15. , Spermatogenesis in Dioon edide. Bot. Gaz. 47:215-236. pis. 



15-18. 1909. 



1 



Pyranema 



iflucns. Zeitschr. Bot. 4:1-64. pis. 1-6. Jig 



igi2] SHARP— SPERMATOGENESIS IN EQUISETUM 115 



17. Dangeard, P. A., Memoire sur les Chlamydononadinees ou Thistoire d'une 
cellule. Le Botaniste 6:65-290. figs. ig. 1898. 

18. — : , Etude sur la structure de la cellule et ses fonctions. Le Polytoma 

uvella. Idem 8:5-58. figs. 4. 1901. 

19. Davis, B. M., Kerntheilung in der Tetrasporenmutterzelle bei Cdrallina 
officinalis L. var. mediterranea. Ber. Deutsch. Bot. Gesells. 16:266-272. 
pis. 16, 17. 1898. 

20. f Nuclear studies in Peliia. Ann. Botany 15:147-180. pis. io y 11. 

1901. 

21 • — 1 Spore formation in Derbesia. Idem 22:1-20. pis. 1-2. 1908. 

22. Escoyez, E., Blepharoplaste et centrosome dans le Marchantia polymorph*!. 
La Cellule 24:247-256. pi. 1. 1907. 

23. Farmer, J. B., and Reeves, J., On the occurrence of centrospheres in 
Peliia epiphylla, Nees. Ann. Botany 8:219-224. pi. 14. 1894. 

24. Farmer, J. B., and Williams, J. L., On fertilization, and the segmentation 
of the spore in Fucus. Idem 10:479-487. 1896. 

2 5- , Contributions to our knowledge of the Fucaceae; their life history 

and cytology. Phil. Trans. Roy. Soc. London B 190:623-645. pis. IQ-24. 
1898. 

26. Faull, J. H., Development of ascus and spore formation in ascomycetes. 
Proc. Boston Soc. Nat. Hist. 32:77-113. pis. 7-11. 190$. 

27. Fraser, H. C. L, Contributions to the cytology of Humaria rut Hans. 
Ann. Botany 22:35-55. pis. 4, 5. 1908. 

28. Fraser, H. C. I., and Welsford, E. J., Further contributions to the 
cytology of the ascomycetes. Idem 22:465-477. pis. 26, 27. 1908. 

29. Fraser, H. C. L, and Brooks, W. E. St. J. Further studies on the cytology, 
of the ascus. Ann. Botany 23:538-549. 1909. 

30- Fuju K. (Has the spermatozoid of Ginkgo a tail or not?). Bot. Mag. 

Tokyo. 12:287-290. 1898. (Japanese.) 
3*« (On the morphology of the spermatozoid of Ginkgo biloba). Idem 

13:260-266. pi. 7. 1899. (Japanese.) 
32. — (Account of a sperm with two spiral bands). Idem 14:16-17. 

I 9°°- (Japanese.) 
33- Gregoire, V., and Berghs, J., La figure achromatique dans le Peliia 

epiphylla. La Cellule 21:193-238. pis. 1, 2. 1904. 
34* Griggs, R. F., The development and cytology of Rhodochytriitm. Bot. 

Gaz. 53:127-173. pis. 11-16. 1912. 
35- Guignard, L., Developpement et constitution des antherozoides. Rev. 

Gen. Bot. 1:11-27, 63-78, 136-145, 175-194. pis. 2-6. 1889. 

36. 1 Centrosomes in plants. Bot. Gaz. 25:158-164. 1898. 

37- Guilliermond, M. A., Recherches sur la karyokinese chez les ascomycetes. 

Rev. Gen. Bot. 16:129-143. pis. 14, 15. 1904. 
38. — , Remarques sur la karyokinese des ascomycetes. Ann. Mycol. 

3 : 344~36i. pis. 10-12. 1905. 



il6 BOTANICAL GAZETTE [august 



39. Guilliermond, M. A., Aperfu sur revolution nucleaire des ascomycetes 
et nouvelles observations sur les mitoses des asques. Rev. Gen. Bot. 

23:89-121. figs. 1-8. pis. 4, 5. 191 1. 

40. Harper, R. A., Beitrag zur Kenntniss der Kemtheilung und sporen- 
bildung im Ascus. Ber. Deutsch. Bot. Gesells. i3:(67)-(68). pi. 27. 1895. 

41. , Kemtheilung und freie Zellbildung im Ascus. Jahrb. Wiss. Bot. 

30:249-284. pis. 11, 12. 1897. 

42. , Cell division in sporangia and asci. Ann. Botany I3 : 467~5 2 5- 

pis. 24-26. 1899. 

43. , Sexual reproduction and the organization of the nucleus in certain 

mildews. Publ. Carnegie Inst. No. 37. Washington, 1905. 

44. Henneguy, L. F., Sur les rapports des cils vibratiles avec les centrosomes. 
Arch. Anat. Mikr. 1:481-496. figs. 5. 1898. 

45. Hirase, S., Notes on the attraction spheres in the pollen cells of Ginkgo 
biloba. Bot. Mag. Tokyo 8:359. 1894. 

46. (On the spermatozoid of Ginkgo biloba). Idem 10:325-328. 1896. 

(Japanese.) 

47. , Untersuchungen iiber das Verhalten des Pollens von Ginkgo 

biloba. Bot. Centralbl. 69:33-35. 1897. 

48. Humphrey, J. E., Nucleolen und Centrosomen. Ber. Deutsch. Bot. 
Gesells. 12:108-117. pi. 6. 1894. 

49. Humphrey, H. B., The development of Fossombronia longiseta Austr. Ann. 
Botany 20:83-108. pis. 5, 6. figs. 8. 1906. 

50. Ikexo, S., Vorlaufige Mittheilung iiber die Spermatozoiden bei Cycas 
revoliita. Bot. Centralbl. 69:1-3. 1897. 

5i- . , Zur Kenntniss des sogenannten centrosomahnlichen Korpers im 

Pollenschlauche der Cycadeen. Flora 85:15-18. 1898. 
52. , Untersuchungen iiber die Entwickelung der Geschlechtsorgane 

und den Vorgang der Befruchtung bei Cycas revoluta. Jahrb. Wiss. Bot. 

32:557-602, pis. 8-10. 1898. 
53« —, Die Spermatogenese von Marchantia polymorpha. Beih. Bot. 

Centralbl. 15:65-88. pi. 3. 1903. 

54- , Blepharoplasten im Pflanzenreich. Biol. Centralbl. 24:211-221. 

figs. 1-3. 1904. 

55- , Zur Frage nach der Homologie der Blepharoplasten. Flora 96: 

538-542. 1906. 

56. Jahn, E., Myxomycetenstudien. 3. Kernteilung und Geisselbildung bei 
den Schwarmern von Stemonitis flaccida Lister. Ber. Deutsch. Bot. 
Gesells. 22:84-92. pi. 6. 1904. 

57. Karsten, G., Die Auxosporenbildung der Gattungen Cocconc'is, Surirclla, 
und Cymatoplcara. Flora 87:253-283. pis. 8-10. 1900. 

58. Korff, K. von, Zur Histogenese der Spermien von Helix pomatia. Arch. 
Mikr. Anat. 54:291-296. pi. 16. 1899. 

59. Lauterborn, R m Untersuchungen iiber Bau, Kernteilung, und Bewegung 
der Diatomeen. Leipzig. 1896. 



i9i 2] SHARP— SPERMATOGENESIS IN EQUISETUM 117 

60. Lenhossek, M. von, Ueber Flimmerzellen. Verh. Anat. Gesell. in Kiel. 
12:106. 1898. 

61. Lewis, C. E., Embryology and development of Riccia lutescens and Riccia 
crystallina. Bot. Gaz. 41 : 109-138. pis. 5-9. 1906. 

62. Maire, R., Recherches cytologiques sur quelques ascomycetes. Ann. 
Mycol. 3:123-154. pis. 3-5. 1905. 

63. Meves, F., Ueber Struktur und Histogenese der Samenfaden von Sala- 
mandrci maculosa. Arch. Mikr. Anat. 50:110-141. pis. 7, 8. 1897. 

64- , Ueber Struktur und Histogenese der Samenfaden des Meer- 

schweinchens. Idem. 54:329-402. pis. 19-21. figs. 16. 1899. 

65. Meves, F., and Korff, K. von, Zur Kenntniss der Zelltheilung bei 
Myriopoden. Arch. Mikr. Anat. 57:481-486. pi. 21. figs. 5. 1901. 

66. Miyake, K., On the centrosome of Hepaticae. Bot. Mag. Tokyo 19:98- 
101. 1905. 

67* , The spermatozoid of Ginkgo. Jour. Appl. Micr. and Lab. Methods 

5 : i773~i78o. figs. 10. 1906. 

68. Moore, J. E. S., Structural changes in the reproductive cells during 
spermatogenesis of elasmobranchs. Quart. Jour. Micr. Sci. 38:275-313. 
pis. 13-16. 1895. 

69. Mottier, D. M., Das Centrosom bei Dictyota. Ber. Deutsch. Bot. 

Gesells. 16:123-128. figs. 5. 1898. 

70. , Nuclear and cell division in Dictyota dichotoma. Ann. Botany 

14:166-192. pi. 11. 1900. 

7 1 - — , The development of the spermatozoid in Chora. Ann. Botany 

18:245-254. pi. 17. 1904. 

72. Paulmier, F. C, The spermatogenesis of Anasa tristis. Jour. Morph. 
i5"Suppl. 223-272. pis. 13, 14. 1899. 

73- Sands, M. C, Nuclear structure and spore formation in Microsphaera. 
Trans. Wis. Acad. Sci. 15:733-752. pi. 46. 1907. 

74- Schaffner, J. H., The centrosomes of Marchantia polymorpha. Ohio 
Naturalist 9:363-388. 1908. 

75- Schottlander , P., Beitrage zur Kenntniss des Zellkerns und der Sexual- 
zellen bei Kryptogamen. Beitr. Biol. Pflanzen Cohn 6:267-304. pis. 
4, 5. 1893. 

76. Shaw, W. R., Ueber die Blepharoplasten bei Onoclea und Marsilia. Ber. 

Deutsch. Bot. Gesells. 16:177-184. pi. 11. 1898. 
77- Smith, H. L., A contribution to the life history of the Diatomaceae. Proc. 

Am. Soc. Micr. Pts. I and II. 1886-1887. 
78* Strasburger, E., Schwarmsporen, Gameten, pflanzliche Spermatozoiden, 

und das Wesen der Befruchtung. Hist. Beitr. 4:49-158. pi. 3. 1892. 
79- , Kerntheilung und Befruchtung bei Fucus. Jahrb. Wiss. Bot. 

3<>"35i-374. pis. 27, 28. 1897. 

80. f Ueber Reduktionsteilung, Spindelbildung, Centrosomen, und 

Cilienbildner im Pflanzenreich. Hist. Beitr. 6:1-224. pis. 1-4* 1900. 

81. Studxicka, F. K., Ueber Flimmer- und Cuticularzellen mit besonderer 
Berucksichtigung der Centrosomenfrage. Sitzungsber. Konigl. Bomisch. 
Gesell. Wiss. Math.-Naturwiss. Classe. Xo. 35. 1S99. 



Ii8 BOTANICAL GAZETTE [august 



82. Suzuki, B., Notiz iiber die Entstehung des Mittelstiickes von Selachiern. 
Anat. Anz. 15:125-131. figs. 6. 1898. 

83. Swingle, W. T., Zur Kenntniss der Kern- und Zelltheilung bei den 
Sphacelariaceen. Jahrb. Wiss. Bot. 30:296-350. pis. 15, 16. 1897. 

84. Thom, C., The process of fertilization in Aspidium and Adiantum. Trans. 
Acad. Sci. St. Louis 9:285-314. pis. 36-38. 1899. 

85. Timberlake, H. G., Development and structure of the swarm spores of 
Hydrodictyon. Trans. Wis. Acad. Sci. 13:486-522. pis. 2Q, 30. 1902. 

86. Van Hook, J. M., Notes on the division of the cell and nucleus in liver- 
worts. Bot. Gaz. 30:394-399. pis. 2, 3. 1900. 

87. Webber, H. J., Peculiar structures occurring in the pollen tube of 
Zamia. Box. Gaz. 23:453-459. pi. 40. 1897. 

88. , The development of the antherozoid of Zamia. Idem 24:16-22. 

figs. 5. 1897. 

89. , Notes on the fecundation of Zamia and the pollen tube apparatus. 

of Ginkgo. Idem 24:225-235. pi. 10. 1897. 

90. , Spermatogenesis and fecundation in Zamia. U.S. Dept. Agri., 

Bureau Plant Ind., Bull. No. 2:1-100. pis. 1-7. 1901. 

91. Williams, J. L., Studies in the Dictyotadeae. II. The cytology of the 
gametophyte generation. Ann. Botany 18:183-204. pis. 12-14. 1904. 

92. Wilson, E. B., The cell in development and inheritance, p. 175- I 9°°- 

93. Wilson, M., Spermatogenesis in the Bryophyta. Ann. Botany 25:415- 

457. pis. 37, 3$. figs. 3. 1911. 

94. Wolfe, J. J., Cytological studies on Nemalion. Idem 18:607-630. pis. 
40, 41. fig. 1. 1904. 

95. Woodburn, W. L., Spermatogenesis in certain Hepaticae. Idem 25:299- 
313. pi. 25. 191 1. 

96. Yamanouchi, S., The life history of Polysiphonia violacea. Box. Gaz. 
42:401-449. pis. ig-28. 1906. 

97- j Spermatogenesis, oogenesis, and fertilization in Ncphrodium. 

Idem 45:145-175. pis. 6-8. 1908. 

98. , Mitosis in Fucus. Idem 47:173-197. pis. 8-1 1. 1909. 

99. , The life history of Corallina. Unpublished. 



EXPLANATION OF PLATES VII AND VIII 

All figures were drawn at the level of the table with the aid of an Abbe 
camera lucida under a Zeiss apochromatic objective 2 mm. 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 



Fig. 1. — Cell of penultimate generation rounding off. 

Fig. 2. — Deeply staining body with faint aster present in cytoplasm. 

Fig. 3. — Division of small body in cytoplasm. 

Fig. 4. — Two blepharoplasts formed by division of the original body. 



' 



BOTANICAL GAZETTE, III 



PLATE VII 




1 




2 




3 




4 





6 





7 



8 




9 






11 



12 




S».%*j. 







SHARP on EQUISETUM 



BOTANICAL GAZETTE, LIV 



PLATE VIII 






18 



19 



17 






22 



20 



21 








23 



24 





25 



bi 




vl 






29 




SHARP on EQUISETUM 



1912] SHARP— SPERMATOGENESIS IN EQUISETUM 119 

■ 

Fig. 5. — Blepharoplasts at upper side of nucleus; other single and paired 
bodies present in cytoplasm; exceptional condition. 

Fjg. 6. — Blepharoplasts beginning to separate; central spindle present; 
the radiations on the side toward the nucleus form a distinct cone. ' 

Fig. 7. — Later stage; no cone of rays present. 

Fig. 8. — Still later stage; central spindle fading out. 

Figs. 9-12. — Stages in the divergence of the blepharoplasts. 

Fig. 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. 

Fig. 14. — Spirem stage: nuclear membrane beginning to break down; 
astral rays much shorter. 

Fig. 15. — Late prophase: the spindle fibers have been formed from the 
radiations of the blepharoplasts, which occupy the poles. 

Fig. 16. — Telophase: blepharoplasts have enlarged and become vacuolate. 

plate vni 

Fig. 17. — Pair of spermatids differentiated: blepharoplasts have the form 
of irregular rings; plastids present in cytoplasm. 

Fig. 18. — Spermatid: blepharoplast beginning to fragment. 

Fig. 19. — Blepharoplast broken up to several pieces. 

Fig. 20. — Granules formed by fragmentation of blepharoplast beginning 
to draw out into a row; nucleus again in resting condition. 

Fig. 21. — Blepharoplast granules arranged in a long row; cilia beginning 
to grow out from them; plastids present. 

Fig. 22. — Blepharoplast granules fusing at right end of chain; still separate 
at left end; degenerating plastids in cytoplasm. 

Fig. 23. — Blepharoplast now a continuous thread; cilia partially 
developed; nucleus beginning its metamorphosis. 

Fig. 24. — Portion of a similar cell viewed from the direction a, showing 
proximity of nucleus and blepharoplast ; cilia not drawn. 

Fig. 25. — Later stage: nucleus and blepharoplast have elongated spirally; 
chromatin network very coarse. 

Fig. 26.— Entire cell similar to that of fig. 25 viewed from the direction a, 
showing independence of nucleus and blepharoplast; cilia not drawn. 

Fig. 27.— Section of similar cell in plane ab: n, nucleus; 6, blepharoplast; 
cilia not drawn. 

Fig. 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. 

Fig. 29. — Smaller spermatozoid in another antheridium, viewed from a 

different direction. 

Fig. 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 /x. 



THE PRIMARY COLOR-FACTORS OF LYCHNIS AND 

COLOR-INHIBITORS OF PAP AVER RHOEAS 1 

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, Punnett) 
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 ii, 12), and Castle (2) also opposes 
such an idea, calling attention to Wood's well known sheep hybrids 
(Wood 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 c^r-character is inhibited, the 

1 Under the title "Inhibiting factors in Lychnis and Pa paver" this paper was 
read before the Botanical Society of America, Washington, D.C., December 28, 
191 1. The change of title and slight changes in the text have been rendeied 
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 paper 
as read, but it withdraws Lychnis dioica for the present as an example of domi- 
nant white. 

Botanical Gazette, vol. 54] I I2 ° 



i9i2] 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 (i, p. 105) and Gregory (7) found that 
white-flowered primulas with red stems are dominant whites, 
while those with green stems are recessive whites; 2 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 inhibitors is seen in 
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 

2 While this is the general rule, Keeble and Pellew (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 stems. 



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 t 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 in vitro of such a 
reaction is the ready reduction of indigo blue (C l6 H IO N 2 2 ) in 
alkaline solutions to indigo white (C l6 H I2 N 2 2 ). 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 Spiegler's conclusions in this regard, 
the general type of reaction suggested by Spiegler 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 



>7 



1912] SHULL— LYCHNIS AND PAP AVER 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 w-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 



dominant 



described below. 



exemplified by the Shirley poppies 



I have been making numerous crosses among strains of Lychnis 
dwica 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 (191 1) all of these crosses 
between white-flowered parents have given uniformly white- 
flowered progenies, 3 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. 

With 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. 4 

3 The several purple-flowered individuals from white-flowered parents, mentioned 
in an earlier paper (Shull 13), appear now to have 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 complementary color-factors here under 
consideration. 

4 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 X| is sufficiently demonstrated by the facts presented 

n my earlier paper. My failure thus far to secure a purple-flowered F t 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 appar 
good reason classified by German taxonomists as distinct spec: 
the white-flowered form being called Melandrium album Garc 
and the purple-flowered form M. rubrum Garcke. Melandri 



my cultures 



moderately 



from 



tube; the styles are long and slender, with inconspicuous stigmatic 
papillae. The plants are easily grown as annuals by early sowing. 
Melandrium rubrum Gar eke , 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 



from 



b 



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 {Lychnis 
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 1010 between the German Melan- 



1912] SHULL— LYCHNIS AND PAP AVER 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 1092 
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 



male from Cold Soring: Harbor. As Melandrium 



■ 

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 

that the F x progeny of any of these five crosses would 



xpect 



from 



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 



different 



M. rubrum with M 
esult. A matins b 



female 



rubrum produced an F T (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 



igi2] SHULL— LYCHNIS AND PAP AVER 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. 5 

Why there should be this segregation of types in the F x , 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 r 
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 (Pa paver 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 

s Note added June 5, 1912. 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 191 1, 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 PAP AVER 129 



from the usual type, the margin being in this case red-violet 6 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 ma tings 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 involved 

6 The color-nomenclature adopted in this paper is based on the spectrum colors, 
as arranged in the Milton Bradley system. Exact shades and tints have been recorded, 
but for the sake of simplicity these have 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 103 10. 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 7 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, i.e., 
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. 

i 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 "margin" 
(distal) . 



i9i 2] SHULL— LYCHNIS AND PAP AVER 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), an< i the 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 stria tion 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 w r ith 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-flow r ered plant with yellow stamens 
which we have seen producing white-flowered progenies when 
mated with red (families 10275 an d 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) an d 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 1 030 1 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 



i9"] SHULL— LYCHNIS AND PAP AVER 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 

be the result of segregation of inhibiting factors, one or 
more of which were heterozygous in one or both parents. 



might 



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 I? in other crosses only white-flowered offspring 
were produced. 

In the "Shirley" poppies (Pa paver Rhocas 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; (b) 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 

Cold Spring Harbor, L.I. 



LITERATURE CITED 



W 



Press. 1909. 



Cambridge: University 



2. Castle, W. E., Heredity in relation to evolution and animal breeding. 
New York: D. Apple ton & Co. 191 1. 

3. Correns, C, Vererbungsversuche mit blass(gelb)grunen und bunt- 



annua. 



Mirabilis Jalapa, Urtica piliilifera, und 
Abst. Vererb. 1:291-329. figs, 2. 1909. 



iqi2] SHULL— LYCHNIS AND PAP AVER 135 



4. East, E. M., Inheritance in maize. Bull. 167, Conn. Agr. Exp. Sta. 
pp. 142. pis. 25. 191 1. 

5. Gortner, R. A., Spiegler's " white melanin" as related to dominant and 
recessive whites. Amer. Nat. 44:497. 1910. 

6. , Studies on melanin: III. The inhibitory action of certain phenolic 

substances upon tyrosinase. Jour. Biol. Chem. 10:113-122. 1911. 

7. Gregory, R. P., Experiments with Primula sinensis. Jour. Genetics 
1:73-132. pis. 3. figs. 2. igu. 

8. Keeble, F., and Pellew, Miss C, White-flowered varieties of Primula 
sinensis. Jour. Genetics 1 : 1-5. 191 1. 

9. Keeble, F., Pellew, Miss C., and Jones, W. N., The inheritance of 
peloria and flower-color in foxgloves (Digitalis purpurea). New Phytol. 
9:68-77. fig. 1. 1910. 

10. Saunders, Miss E. R., On inheritance of a mutation in the common 
foxglove (Digitalis purpurea). New Phytol. 10:47-63. pi. 1. figs. 14. 
1911. 

11. Shull, G. H., The "presence and absence " hypothesis. Amer. Nat. 
43:410-419. 1909. 

12. 1 A simple chemical device to illustrate Mendelian inheritance. 

Plant World 12:145-153. pi. 1. fig. 1. 1909. 

13* , Color inheritance in Lychnis dioica L. Amer. Nat. 44:83-91. 1910. 

14. Spiegler, E., Ueber das Haarpigment. Beitr. Chem. Physiol. Path. 

4:40. 1904. 
15* Wood, 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 191 1 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 ioin 



Macbride 



month of July, at which time 



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 
Macbride'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 10-striate: leaves 9-15-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 : 



conspicuous, 4-6 cm 



1 



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 



i9i A 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 
15, 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, 191 1, 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, 
5-10-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. trxtncatum T. & G. Proc. Amer. Acad. 
& :i 73, but differing essentially in habit. That may perhaps best be described 



138 BOTANICAL GAZETTE [august 



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 Nelson and Macbride at Shoshone, 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. 

The 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, i-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 
i-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 Macbride in the grass among the sagebrush, on the plains 
near New Plymouth, April 24, 191 1, no. 773. 

Arabis lignipes impar, n. var. — Larger and coarser than the 



nip 



1900), the lignescent 



more enduring, often 8-10 cm 



only by the scalelike leaf bases: pubescence extending to the 



mature 



The type of this variety is Macbride's no. 828, dry, stony slopes, on Squaw 
Creek, Sweet, Idaho, May 8, 191 1. I refer here also specimens by C. N. Woods, 
Hailey, Idaho, no. ga, 1910. 

Draba lapilutea A. Nels. in Coult. & Nels. Man. 222. 1909. 
D. yellowstonensis Al Nels. Bot. Gaz. 30:189. 1900. — Fine speci- 
mens of this strongly marked species were secured by Nelson and 
Macbride on a high mountain near Mackay. It accords very 
closely with the type except that some of the specimens indicate 



may sometimes 



The flowers are 



m 



McCalla 



1901, 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 - l° n g> somewhat cinereous with a stellately 
branched pubescence: inflorescence a short crowded corymbose 



almost 



umbellate 



10- 1 c mm. lone: nods oblong or bicuneate. 2-x cm 



HO 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 Columbus I. Huddle, 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. Huddle's watchful 
supervision, July 30, 191 1. Distributed under Nelson and Macbride s 



no. 1466. 



LISMA 



— Annual or winter annual, 



mmu 



g from 



dm 



? 



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. Nelson and Macbride's no. 1145, King Hill, July 16, 
191 1, 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, 10-14 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. 



IQI2] 



NELSON— IDAHO PLANTS 



141 



This splendid species is nearest to T. breviflora Nutt., i 
different that there is no need to emphasize the differences. 



Jordan Valley, near Silver City, J 



Macbride 



type. It seems to occur in the rich soil of river bottoms. 

Cicuta cinicola, n. sp. — From a thick stout root (P) 1 widely 

or less) high: leaves large; the 



m 



more 



m 



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- 



cm 



5 



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 




— Cicuta 



numerous, 3-7 mm. long; fig. ] 

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 

long: the carpels somewhat 
xmilatcral: the low rounded 



mm 



more 



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). 

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. 



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. Nelson and Macbride'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 




Fig. 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 pinna tely 
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 

) even in fruit: pedicels nearlv wanting: seeds flattened 



mm 



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 

al side: calyx lobes evident : 



commissu 



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 Phcllopterus, but the char- 



i9"] NELSON— IDAHO PLANTS 143 

acteristic caudex and the presence of the stylopodium leave scarcely any doubt 
that it is a Cynomarathritm. 

Secured by Macbride in the shale slides near the summits of the moun- 



J 



1502. 



Dodecatheon pauciflorum shoshonensis, n. var. — Similar to 
the species in size, but the root system consisting of a short corm 



seem 



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 Macbride at Shoshone Falls, July 26, 191 1, no. 1362. 

Phacelia firmomarginata, n. sp. — Annual or possibly biennial, 2 
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, 4-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, 191 1, 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 

2 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 Macbride's no. 1192 from 
Ketchum, July 19, 191 1, 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, 



cm 



more 



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 

or less reflexed lobes half as loner as the tube : tube less than 



more 



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 



mbryo, developing muci 



when wetted. 



This rather extraordinarily strong species falls into the section Elapho- 



rand 



Until now 



this section contained no perennials. 



Mr 



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 Nelson and Macbride's no. 11 26, from loose white 
clay banks, a few miles from King Hill, Idaho, July 16, 191 1. 

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 



i9"] NELSON— IDAHO PLANTS 



J 45 



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. 
3° : *94> 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. 131 1, from sagebrush plains, near 
Minidoka, July 24, 191 1. 

Pentstemon confertus Dough— 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. attenuates, P. confertus, and P. procerus, all by Doug- 
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 
wrecking of several pseudo-species, among which may be named P. micranthus 
Nutt., P. Owenii and P. Rydbergii A. Nels., P. pseudo procerus Rydb., and a 
score (more or less) of Dr. Greene's species (see vol. I of Leaflets). 

As excellent examples of P. attenuatus Parians, I name Macbride's no. 974? 



i9i a] NELSON— IDAHO PLANTS 147 

Twilight Gulch, Owyhee County, June 23, 1911, and his no. 1693, Pinehurst, 
Boise County, August 17, 191 1. 

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 
hairs. 



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. Nelson and Macbride, 
no. 1 196, Ketchum, July 19, 191 1. 

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. 



Macbride 



J 



Pentstemon erianthera Whitedii, n. comb. — P. Whitedii 



Piper, Box. Gaz. 22:490. 1901. 

Mr. Piper, in Contrib. Nat. Herb. 1 1 : 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 carried as a variety of 
the typical Rocky Mountain P. erianthera. 

Nelson and Macbride's no. 142 1, secured at Mackay, on gravelly sage- 
brush slopes, July 30, 191 1, 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 Macbride'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 



more 



third of the plant: pubescence inconspicuous, very softly lanate 



cm. loner, numerous 



5 



sometimes 



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. 



19"] NELSON— IDAHO PLANTS 149 



In spite of the large number of species of Castillcja 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 Macbride's 1261, secured on 
disintegrated granite slopes at Ketchum, Blaine County, Idaho, July 21, 191 1. 



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 Smith, 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. ockrocephalum 
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 



petals 



Mc 



pnmari 



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 7-1 1, 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 



guished 



lotifl 



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. 



May 



J 



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 



1912] NELSON— IDAHO PLANTS 151 



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 
might 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. Woods, 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, 191 1. 

University of Wyoming 
Laramie, Wyoming 






BENEFICIAL EFFECT OF CREATININE AND CREATINE 

ON GROWTH 1 

J. J. Skinner 

(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. Shore y, 2 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 3 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. 4 

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 

1 Published by permission of the Secretary of Agriculture, from the Laboratory 
of Soil Fertility Investigations. 

2 Shorey, Edmund C, The isolation of creatinine from soils. Jour. Amer. 
Chem. Soc. 34:99. 191 2. 

3 Sullivan, M. X., The origin of creatinine in soils. Jour. Amer. Chem. 
Soc. 33*2035. 191 1. 

4 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. Bot. Gaz. 50: 1. 1910. 

Botanical Gazette, vol. 54] l l S 2 



/ 



IQI2] 



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 



containing no nitrate 



Table I gives the growth of two sets of cultures composed of 



mixtures 



TABLE I 

Showing the effect of creatinine on growth in cultures containing no 

nitr; 



No. 



1 
2 

3 

4 

5 
6 

7 
8 

9 
10 

11 



PPM. OF FERTILIZER INGREDIENT IN CULTURE 

SOLUTION 



P.O, 



O 

8 

16 

24 
32 
40 

48 

56 
64 

72 

80 



Nft 



o 
o 
o 
o 
o 
o 
o 
o 
o 
o 
o 



KaO 



80 

72 
64 

56 

48 
40 

32 

24 
16 

8 



Green weight of culture 

IN GRAMS 



Without 
creatinine 



1.400 
I.470 

I -05O 

1-527 
I.490 

1-558 

1-795 
1.540 

1.444 
1.400 

1. 100' 



With 

creatinine 






I.576 

2.200 

2.IOO 
2.000 
2.200 
2.408 
2.328 
2.400 

2. 2 20 
2. IOO 
I. 150 



154 



BOTANICAL GAZETTE 



[august 



there being no nitrate in the solutions; the concentration was 
80 ppm. of P 2 5 +K 2 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 



\ , 


















Fig. i. — Wheat plants growing in culture solutions containing various propor- 
tions of potash and phosphate (with no nitrates) without (a) and with (b) creatinine 



considerable increase in growth. 



true 



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 b have 



IQI2] 



SKINNER— CREA TININE A ND CREA TINE 



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, 
able in the roots as well as the tops. The tops in each case are 



The increased growth is notice- 



branched 



Effect of creatinine in cultures containing 8 ppm. NH 3 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 



of fertilizer mixtures, containing 8 PPM. OF NH 3 AS nitrate 


No. 


PPM. OF FERTILIZER INGREDIENTS IN CULTURE 

SOLUTION 


Green weight of culture 

IN GRAMS 


PA 


NH 3 


K,0 


Without 
creatinine 


With 
creatinine 


I 




8 

16 

24 
32 
40 

48 

56 
64 

72 


8 
8 
8 
8 
8 
8 
8 
8 
8 
8 


72 

64 

56 

48 

40 

32 

24 

16 

8 




1.820 

2.470 

2.748 

2.907 
2.670 
2.928 

2.526 

2.600 
2.048 

1.354 


2.190 
3.100 
3250 
3.420 

2.450 
3-253 

3 -340 
3.000 

2-359 
1 -750 


2 


3 


4 


s 


6 


7 


8 




10 





effect of creatinine on growth in culture solutions composed of 
8 ppm. of NH 3 as nitrate, and varying amounts of phosphate and 
potash, the total concentration of each solution being 80 ppm. of 
PaOs+NHj+KjO. By comparing the figures it is seen that the 
growth with creatinine, given in the last column, is larger than th< 
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 3 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 16 ppm. NH 3 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 3 

as nitrate 



No. 



I 

2 

3 

4 

5 
6 

7 
8 

9 



PPlf. OF FERTILIZER INGREDIENTS IN CULTURE 

SOLUTION 



PaO 



O 

8 

16 

24 

3 
40 

48 

56 
64 



NH, 



16 
16 
16 

16 

16 

16 
16 
16 
16 



K,0 



64 

56 
48 

40 

32 

24 
16 

8 






Green weight of cultures 

in grams 



Without 
creatinine 



2.200 
3.200 

3 097 
3-250 
3.228 

2-975 
2.626 

1.440 



With 
creatinine 



2.570 
3.720 

3-SOO 

3.702 

3-250 

3-3°° 
3.240 

2-55 1 
1.740 



comDosed of the 



P,Oc. NH 



5' 



3' 



NH 



nitrate, 



creatinine increased growth only 2 per cent. Its effect in cultures 



i9i 2] SKINNER— CREATININE AND CREATINE 157 



composed of fertilizer mixtures having more than 24ppm. of 
nitrate was uncertain; in 



some 



growth and in others there was a slight decrease, that is, the growth 



amounts 



same 



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, 5 it was shown that the 
better growth occurred in the normal cultures when the three fer- 
tilizer elements P 2 s , NH 3 , and K 2 were present. It was best in 
mixtures which contained approximately equal amounts of NH 3 
and K 2 and a small amount of P 2 5 (about i6ppm.). 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 8oppm. of P 2 5 +K 2 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 3 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 3 as 
nitrate, was 2 . 107 grams. 

In 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 3 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 Skinxer, J. J., Ratio of phosphate, nitrate, and potassium 
on absorption and growth. Bot. Gaz. 50: 1. 1910. Some effects of a 1 
soil constituent. Bull. 70, Bureau of Soils, U.S. Dept. Agric. 1910. 



irm 



i58 



BOTANICAL GAZETTE 



[august 



but 8ppm. of NH 3 . The average growth of the cultures without 
nitrogen is 1.516 grams against 2.407 grams with 8ppm. of NH 3 
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 3 AS nitrate, without and with creatinine 



No. 



I 

2 

3 

4 

5 
6 

7 

8 

9 

10 

11 
12 

13 

14 

IS 

16 

17 

18 

19 

20 

21 



PPM. OF FERTILIZER INGREDIENTS 
IN CULTURE SOLUTION 



P.O 



o 

8 

8 

16 

16 

24 

24 

32 

32 
40 

40 

48 
48 
56 

56 

64 
64 

72 

72 
80 



XH, 



K,0 






80 


8 


72 





72 


8 


64 





64 


8 


56 





56 


8 


48 





48 


8 


40 





40 


8 


32 





32 


8 


24 





24 


8 


16 





16 


8 


8 





8 


8 












Green weight of cultures in grams 



Without creatinine 



No nitrate 



1 .400 



I.470 



I.950 



I-527 



I.490 



1.558 



1-795 



I.540 



I.444 



I.400 



I. IOO 



8 ppm. NH 3 



I .820 



2.470 

2.748 
2.907 
2.670 



• • • 



2.928 
2.526 



2.600 



2.048 



1-354 



With creatinine 



No nitrate 8 ppm. NH 3 



1576 



2. 200 



2.IOO 



• ♦ 



2.000 



2.200 



2.408 
2.328 



2.4OO 



2. 220 



2.IOO 



1.15° 



2. I9O 



3.IOO 

3.250 
3.420 

2.450 



• ■ 



3.258 
3340 
3.OOO 

2.359 
I-750 



With 50 ppm 



the solution, the cultures con- 



taining no nitrogen produced better growth than the corresponding 



wi 



columns 



table IV. The difference between the last two 
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 3 as nitrate in the fertilizer mixture. If the growth 
of the cultures without nitrate is put at 100, the growth with 8 ppm. 



igi2] SKINNER— CREATININE AND CREATINE 159 



of NH 3 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 2 5 , NH 3 , and K 2 removed from solution by 
the growing plants in the cultures containing all three of these 



milligrams 



milligrams 



The figures show the total 



of plant nutrients to be slightly less in the creatinine set, although 
the green weight in this set was 9 per cent greater than in the normal 
set. The examination of the results for the three constituent 
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 F 2 5 removed 
from the total number of solutions during the experiment was 364 
milligrams for the normal cultures and ^8^ 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 2 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 3 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 

1 

of 8 per cent over the normal cultures. 

Table V shows the effect of creatine on growth in a number of 



1912] 



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 8oppm. 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 



No. 


PPM. OF FERTILIZER INGREDIENT IN CULTURE ! 

SOLUTION 


Green weight of cultures 

IN GRAMS 


P 3 5 


NH, 


K,0 


Without 
creatine 


With 
creatine 


I 




8 

16 

24 

32 
40 

48 

56 

64 
72 
80 


ooooooooooo 


80 
72 

64 

56 

48 

40 

32 

24 

16 

8 




I 1 on 


I.709 
I.948 
2.130 
2.370 
2.470 
2.400 

2 2 TO 


2 


X 1 

I 
I 
I 
I 
I 
I. 

I. 
I. 
I. 




.420 

• 558 

■ 579 
.528 

.500 
,670 
,628 
.600 
.428 

978 


3 


4 


5 


6 


7 


8 


2.420 
2.450 

2 070 


Q 


IO 


II 


I.090 




^^ > 



In table VI are given the green weights of plants grown in 
cultures with and without creatine, containing 8ppm. of NH 3 
as nitrate and varying amounts of P 2 O s and K 2 0, the total 
constituents being 8oppm. of P 2 O s +NH 3 +K 2 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 
11 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 i6ppm. 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 3 as nitrate 



No. 



1 
2 

3 

4 

5 
6 

7 
8 

9 
10 



PPM. OF FERTILIZER INGREDIENT IN CULTURE 

SOLUTION 



PaO 



O 

8 

16 
24 

32 

40 

48 
56 

64 

72 



NH 3 



8 
8 
8 
8 
8 
8 
8 
8 
8 
8 



KaO 



72 

64 
56 

48 
40 

32 

24 
16 

8 



Green weight of cultures 

IN GRAMS 



Without 
creatine 



2.299 
2.940 
2.700 
2.920 

3°50 

3-!5o 
3.220 

2.500 

2.222 

1.400 



With 
creatine 



2. 459 
3.200 

3-3SO 
3.400 

3.070 
3-309 

3 -350 

2.854 
2.800 

1 .600 



5 



emoval 



milarity 



creatine and creatinine in this respect. 
in the creatinine cultures the removal 



remem 



but a great deal less nitrate 
creatinine than in the normal ( 



cultures than the normal 
lisaDDeared from solutio 



experiments the removal of total P 2 5 , NH 



K 




plants in the normal cultures was 1978.3 



mi 



milligrams 



The normal 



cultures removed 471.0 milligrams 
tures A7A.A milligrams. In the casi 



normal 



iqi2] SKINNER— CREATININE AND CREATINE 163 



removed 769.4 milligrams of K 2 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 2 5 , 
NH 3 , and K 2 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 of Soils, U.S. Department or Agriculture 

Washington, D.C. 



BRIEFER ARTICLES 



A NOTE ON THE GENERATIONS OF POLYSIPHONIA' 

(with one figure) 

Yamanouchi 2 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, Ceramiutn 
rubrum, and C allithamnion 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 3 has attempted an experimental test of the truth of Yama- 
nouchi'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 
Bornctiana, 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 

1 Contributions from the Puget Sound Marine Station, no. 2. 

2 Yaman-ouchi, S., The life history of Polysiphonia. Bot. Gaz. 42:401-449- 
1906. 

3 Lewis, I. F., Alternation of generations in certain Florideae. Bot. Gaz. 53 : 236- 
242. 1912. 

Botanical Gazette, vol. 54] 






[164 



igi2] 



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 191 1 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 191 1. 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 




W. A. Setchell 



Fig. i.— Camera lucida drawing of 



University of California as Pterosi- a portion of a ^/^/M^naC?) show- 

7 . mg on the same individual both 

phonia bipinnata and by Dr. Shigeo tetraS p 0res an d 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- 

were not abortive. We have thus an indi- 



cystocarps 



vidual that is both sexual and asexual, which is inconsistent with there 



species 



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.— George B. Rigg and Annie D. Dalgity. 



CURRENT LITERATURE 



BOOK REVIEWS 
Forest physiography 1 

This volume, intended primarily for the use of foresters, will be of very 
great value to ecologists, even to those working upon problems which are 
unrelated to forests. Its field of usefulness extends farther still, for it is the 
first work in which the much-scattered literature 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 Bowman's work w T ill 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; chemical 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 Merriam'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 



1 Bowman, Isaiah, Forest physiography, pp. xxii + 759. ph. 6. figs. 2Q2. New 



York: John Wiley & Son, 191 1. 



166 



19"] 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 w r hich 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. On 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 

7 

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. 
On 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 
spruce," with no mention of the balsam, which is the more important of the 
two. On the same page, the author places the hemlock where it rightly 
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. — William S. Cooper. 



A Yosemite flora 



Mrs 



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 2 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 
size of the great state of California, nor to the great size of the Park botanically 
considered. Within its 102*1 sauare miles there are probably more kinds of 



d climate t 
topography 



This 



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 Hall, Harvey Monroe and Carlotta 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 terms; 
interesting notes on habitat, habit, distribution, etc; n beautiful halftone 
plates in brown, and 174 instructive figures; a glossary and a complete index. 
This little manual of nearly 300 pages is significant in many ways. It indicates 
an increasing interest in technically correct science simply 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 
families, 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; 
and a 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 belongs in another range, even though that name has long been 
used in ours. 

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. Abrams (Muhlenbergia 8:26-44- 
191 2) 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 12:11-13. 191 2) has published a new Habenaria (H. Brittonae) from 
Cuba.— J. C. Arthur (Mycologia 4:40-6=;. 1012) records the results of con- 



tinued studies on the " Cultures of Uredineae in 191 1."— 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 {Prit- 
chardiopsis) of this family from New Caledonia. — A. Brand (Rep. Sp. Nov. 
10: 280, 281. 191 2) characterizes a new genus (Namation) of the Scrophulariaceae 
based on the Mexican plant Nama glandulosum Peter. The same author 
{ibid. 281) proposes the name Andropus carnosusiox the plant hitherto doubt- 



i9i 2] CURRENT LITERATURE i6q 



fully referred to the genus Conanthus. — N. L. Brixton (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. 191 2) 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. 191 2) 
under the title "Intorno a due nuovi generi di piante appartenenti alia famiglia 
delle Malpighiaceae" proposes two genera, namely Tetraspis and Eriocau- 
cantus. — A. Cogniaux (Rep. Sp. Nov. 10:343, 344. 191 2) describes a new 
species of Epidendrum {E. Rojasii) from Paraguay. — L. Diels (Leafl. Phil. 
Bot. 4:1161-1167. 191 1) 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, 
1 1 7-1 20. 191 1) 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 
plants. — A. Engler (Bot. Jahrb. 48:224-336. 1912) in collaboration with 
several specialists has issued "Beitrage zur Flora von Afrika XL." About 
120 species new to science are published, belonging mostly to the Solanaceae, 
Polygonaceae, and Umbelliferae. Four new genera of the Umbelliferae are 
proposed, namely Afrosison, Marlothiella, Volkensiella, and Frommia. — 
F. Fedde (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. Fernald and K. M. Wiegand (Rhodora 14:35, 36. 1912) record a 
new variety of J uncus {J. balticus var. melanogenus) from Quebec. — C. N. 
Forbes (Occ. Papers Bern. Pau. Bish. Mus. Ethl. and Nat. Hist. 5:1-12. 
191 2) under the title "New Hawaiian plants III " has published 4 new species 
of flowering plants.— E. L. Greene (Leafl. Bot. Obs. and Crit. 2:165-228. 
191 2) has described about 100 new species of North American flowering plants 
mostly referred to Apocynum and Erigeron. — D. Griffiths (Rep. Mo. Bot. 
Gard. 22:25-36. pis. 1-17. 191 1) 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. pis. 515, 516. 1912) in an article 
entitled "New or noteworthy Fungi, part IV" includes the description of a 
new genus (CryptostictcUa) found on leaves of Tilia curopea 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 Mycosphacrella polys pora Johans. — E. Hackel (Rep. 
Sp. Nov. 10:165-174. 1911) under the title "Gramineae novae VIII" 
describes several new 7 species of grasses including 9 from Mexico and South 
America. — E. Hassler {ibid. ? 344-348. 191 2) 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. pi* 4) records a new Apocynum (A. cinereum) from the same state. 
G. Hieronymus (Rep. Sp. Nov. 10:41-53, 97-116. 191 1) has published 19 
new species of Selaginella from the Philippine Islands. — P. B. Kennedy 
(Muhlenbergia 7:133-136. 191 2) describes a new willow {Salix caespitosa) 
from Mt. Rose, Nevada. — F. D. Kern (Torreya 11:211-214. 191 1) records 
2 new species of Uromyces from the Central and Southern States. — F. Kranz- 
lin (K. Sv. Vet. Akad. Handl. 46: no. 10. 1-105. pis. I-IJ. 191 1) under the 
title "Beitrage 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. Kukenthal (Leafl. 
Phil. Bot. 4:1169-1170. 1911) records a new Car ex (C. palawanensis) from the 
Philippine Islands. — H. Leveille (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. pis. 58-61. 1912) describes and illustrates 
a new black knot disease (Bagniesiella Diantherae) found on Diantkera atneri- 
cana at Austin, Tex. — J. Lunell (Am. Mid. Nat. 2:169-177, 185-188, 194, 
195. 191 2) describes new species and varieties in Laciniaria, Toxicodendron, 
and Gutierrezia. — T. H. Macbride (Mycologia 4: 84-86. pi. 62. 191 2) describes 
and illustrates a new Geaster (G. juniperinus) from Iowa. — T. Makino (Bot. 
Mag. Tokyo 25:251-258. pi 7. 1911) under the title of " Observations on 
the Flora of Japan" describes and illustrates a new genus {M itrastemon) 
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. Martelli (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. 191 2) records the results of a study of the genus P hatter ophlebi a 
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. Murrill (Mycologia 4:72-83. 
191 2) in a fifth article on the "Agaricaceae of tropical North America" treats 
13 genera and describes new species in Mycena, Pluteolus, Conocybe, Naucoria, 
Cortinarius, Inocybe, and Hcbeloma. The same author {ibid. 91-100) gives a 
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. Nieuwland (Am. Mid. Nat. 2:178-185. 191 2) 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. 



iqi2] " CURRENT LITERATURE 171 



Geotropism.— Ritter^ applies the rotation method of Piccard^ for 
determining the distribution of geotropic sensitiveness in various grass seed- 
lings. Ritter 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 saliva, 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 Set aria italica 
all regions of the coleoptile are equally sensitive, while 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. 

In a study of the geotropism of rhizoids carried out in Haberlaxdt's 
laboratory, Bischoff 6 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. Bischoff 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 {Br yum capi/lare, B. 
argenteum, and Leptobryum pyriforme) is positively geotropic in light, while 
the protonemata and side rhizoids are ageotropic. In the mosses statolith 
starch is found in the main rhizoid. 

Jost and Stoppel 7 have established 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 Ritter, Herman von Guttenberg, Uber die Verteilung der geotropischen 
Empfindlichkeit in der Koleoptile von Gramineen. Jahrb. Wiss. Bot. 50:289-327. 
fig- f* 1912. 

4 Pfeffer, W., Physiology. English ed. 3:418-419. 1905. 

5 See review of Darwin in Bot. Gaz. 46:387. 1908; also review of Haberlandt 
in Bot. Gaz. 47:482-483. 1909. 

6 Bischoff, Hans, Untersuchungen liber den Geotropismus der Rhizoiden. 
Beih. Bot. Centralbl. 28:94-133. 1912. 

7 Jost, L., and Stoppel, R., Studien uber Geotropismus. II. Die Veranderung 
der geotropischen Reaktion durch Schlenderkraft. Zeitsch. Bot. 4:207-229. 1912. 



172 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 8 is confirmed by this work. The quantity of 
stimulus necessary for a negative response is about iooo times that necessary 
for a positive response. 

Jost 9 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, w r hich 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, 10 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 o . 5-0 . 7 5 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 Nemec's conclusion that statolith starch is necessary in the tip for geo- 
perception lacks evidence, and that such a conclusion was drawn because 
Nemec 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 






8 See review of Blaauw in Bot. Gaz. 49:238. 1910. 

9 Jost, L., Studien liber Geotropismus. I. Die Verteilung der geotropischen 
Sensibilitat in der Wurzelspitze. Zeitsch. Bot. 4:161-205. 1912. 

10 See review in Bot. Gaz. 47:482. 191 2. 



igi2] 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. — Sorauer, 11 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 tendency 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 #re 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. 

Cells 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 Primus, the following species are studied: Corylus avellana, Pinus Laricio, P. 
silvestris, Fagus silvatica, Fraxinus excelsior, F. Ornus, Syringa vulgaris, Cytisus 
Laburnum, Tilia sp., Ampclopsis sp., Platanus sp., and the pear. Scant atten- 
tion is given to the work of previous investigators. These papers are of great 



deduct 



affi 



11 Sorauer, Paul, Untersuchungen fiber Gummifluss und Frostwirkungen bei 
Kirschbaumen. Landwirtsch. Jahrb. 39:259-297. pis. 5. 1910; and 41:131-162. 
pis. 2. 191 1. 



174 BOTANICAL GAZETTE [august 



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 

of air through wounds. Butler considers that " gum- 



caused by admission of air through wounds, 
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 
these two conditions are present gummosis may develop " autogenously " or 



stimulates 



Contrary 



lay 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. — 



Metcalf 



Root habits of desert plants. — In studying the roots of plants growing 
near the Desert Laboratory, Tucson, Ariz., Cannon 13 has made a rather 
detailed investigation of more than 60 species, including winter and summer 



types 



type 



agnized 



very 



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 
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 



12 Butler, Ormond, A study on gummosis of Primus and Citrus, with observa- 
tions on squamosis and exanthema of the Citrus. Ann. Botany 25:107-153* P ls - 4- 
1911. 

n Cannon, W A., The root habits of desert plants. Carnegie Institution of 
Washington. Publ. No. 131. pp.96, pis. 23. 1911. 



i9i 2] CURRENT LITERATURE 175 



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. — Geo. D. Fuller. 

Chromatophores and chondriosomes. — Forenbacher 14 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- 
bell and granular structures which gradually pass over into the chromatophores. 
Similar gradations are found between the chondriosomes (mitochondria) of the 
root tip and the leucoplasts. This work thus confirms the results of Pexsa 
and Lewitsky and those of Guilliermond on the origin of the chloroplasts 
from mitochondria (chondriosomes). 

Some doubt is justified of the efficiency of the methods employed for 
demonstrating the chondriosomes of plant cells. Meves, for example, found 
these structures in the tapetal cells of Nyrnphaea, 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 
his fixing fluid, Forenbacher has diminished its already slight power of pene- 
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 Holdex 15 has investigated the 
position of Salicales on the basis of the vascular anatomy of the North American 

14 Forexbacher, Aurel, Die Chondriosomen als Chromatophorenbildner. Ber. 
Deutsch. Bot. Gesells. 29:648-660. pi. 25. 191 1. 

15 Holden, Ruth, Reduction and reversion in the North American Salicales. 

Anil. Botanv 26: t6c-t7i> /i/c on it Tm? 



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. The 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. 



fruit of Compositae. — Lavialle 16 has begu 



volume 



Compositae, a complex of testa and pericarp. The first chapter and part of 
the second have appeared in the Annates as cited. Since 298 species, repre- 



observations 



great. Just 



of the 



.. 



very 



)bvious. In the account 
the fruit of Compositae," 
apparent. The citations 
are few, and apparently no contributions in English were available. — J. M. C. 

A new Cordaites. — Miss Benson 17 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 



Wedek 



Mitrosp 



with it in the deposit. The whole leaf is said to have "a markedly xerophilous 
character."— J. M. C. 



16 Lavialle, P., Recherches sur le developpement de l'ovaire en fruit chez les 
Composees. Ann. Sci. Nat. Bot. IX. 15:39-64. 1912. 



a ret 



Lower Coal Measures of England. Ann. Botany 26: 201-207. pi. 22. fig. i> i9 12 - 



Vol. LIV 



THE 





September 1912 



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. Woif 



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 by Aragallus Lamberti 



C. D wight Marsh 



Current Literature 



The University of Chicago Press 

CHICAGO, ILLINOIS 

A gent 9 
THE CAMBRIDGE UNIVERSITY PRESS, London and Edinburgh 

WILLIAM WESLEY 6\ SON, London 

TH. STAUFFER, Leipzig 

THE MARUZEN-KABUSHIKI-KAISHA, Tokyo, O.alra, Kyoto 



TCOnHnHH^Hn^^^^K^^^^^VHBI^B^^H^^^^BKB^^BBi^^Mi 









XLhc Botanical (3a$ette 

a /BontblB journal jembracinfi all Departments of JBotanical Science 

Edited by John M. Coulter, with the assistance of other members of the botanical staff of the 

University of Chicago. 

Issued September 2I t 19 1 2 



Vol. LIV CONTENTS FOR SEPTEMBER J9J2 No. 3 



THE LI1 . Ml TORY OF VXEl'RA PIXGUIS. Contributions from the Hull Botanical 

Laboratory 159 (with plates ix -xn). Grace L.Clapp - - - - - - -177 



PLANT GEOGRAPHY OF NORTH CENTRAL NEW MEXICO. Contributions from 

Hull Botanical Laboratory 160 (with seven figures). /. R. Watson - - - i°4 

THE PERFECT STAGE OF A( TIXONEMA ROSAE (with plate xiii). Frederick A. Wolf 21 
UNDESCRIBED PLANTS FROM GUATEMALA AND OTHER CENTRAL AMERICAN 



REPUBLICS. XXXV. John Donnell Smith 



-35 



INFLUENCE OF PHOSPHATE ON THE TOXIC ACTION OF CUMARIN. J. J. Skinner 2+5 

BRIEFER ARTICLES 

At >rption of Bariim Chloride by Ara axes Lamberti. C. Divight Marsh - - 2 5° 



CURRENT LITERATURE 

BOOK REVIEWS - 

LOl v'S TEXTBOOK 

MINOR NOTICES - 
NOTES FOR STUDE TS 



253 



254 
54 






The Botanical Gazette is published monthly. *• The subscription price is I7.00 per year; the price 
of single copies is 75 cents. r Postage is prepaid by the publishers on all orders from the United States, 
Mexico, Cuba, Porto Rico, Panama Canal Zone," Republic of Panama, Hawaiian Islands, Philippine 
Islands, Guam, Tutuila (Samoa), Shanghai. *~ Postage is charged extra as follows : For Canada, 35 cents 
on annual subscriptions (total $7. s5),on single copies, 3 cents (total 78 cents for all other countries in the 
Postal Union, 84 cents on annual st|l cription (total #7.84)2*011 single copies, II cents (total 86 cents). 
•Remittances hould be m le payable to The Universit of Chicago Press, and should be in Chica » or 
sew York exchange, postal or t press money order. If local check is used, 10 cents must be added for 
collection. 

The following agents ha : been appointed and are authorized to quote the prices indicated : 

For he British Empire: The Cambridge University Pre . Fetter Lane, London, EC, and William 
Wesley S >n, 28 ] sex Street, Strand, London. Yearly subscriptions, including postage, £1 1 2 J. oJ. 
each; single copies, including p tagt J 6d. each. 

For the Continent of Europe: Th. Stauffer, Universitats tsse 26, Leipzig, Germany. Yearly sub- 
scri] , including postage, M $3 each ; single copies, including postage, M. 3.60 each. 

For Japan and Korea: The Maruzen-Kabushiki-Kaisha, 11 to 16 Nihonbashi Tori Sanchome, Tokyo, 
Japan. Yearly subscriptions, including po ige, Yen 15.75 each; single copies, including postage, \en 
r.75 each. 

: Claims for missing numbers should be made within the month following the regular month of publi- 
cation. Tin Htblishers pect to supp ng numbers free onlv when they have been 1 \t in tran . 

Business correspondence aid be a tressed to The Universi of Chicago Press, Chicago, III. 

Communications for the editor puld be addressed to him at The University of Chicago, Chicago, Hi. 

Contributors request 1 to write scientific and proper names v> h particular care, t use the metric 
stem of and measures, and in citations to follow the form shown in the pages of the BtfTANJ U* 

Gazette. 

Papers in exc f thir -two printed | *es are not accepted unl the author willing to pz e 

cost oi the additions in 1 e the number of j ges in the volume is eorresp< in ■en 

111 -trations re furnished without cost to author on! lien uitable original are pplied. A co? 
of the ;e made in the January mnn 1907, will be sent on application. It is advisable 

confer wit:, the editor 5 to illu rations required in any article to be ffered, . 

Separates, if desired, must be ordered in advai >f public Twditv-five separates Iiai 

articles with covers will be supplied gratis. A table showir, proximate cost of additional separate 

is printed on an order blank which aecompanie he proof; a copy wi be sent on reqi: 

Ente I A 21, it the Pc "nee at Chicago, as second-class matter, uiider Act of Congress Marc 



: 1 



VOLUME LIV 



NUMBER 3 



THE 



Botanical Gazette 



SEPTEMBER 1912 



the life history of aneura pinguis 

CONTRIBUTIONS FROM THE HULL BOTANICAL LABORATORY 1 59 

Grace L Clapp 

(WITH PLATES IX-XIl) 

Historical 

In his classical study of liverworts, Leitgeb (19) has given a 
comparative treatment of the genus Aneura. 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. 
Hofmeister (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 Clerc du 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. Land 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 p 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 pinguis 
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. 



p 



margins 



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). 



compact 



main axis of the 



mi 



the plant is usually thicker along the center, thinning out toward 



margins 



some 



time and the plastids often have 5 or 6 starch grains. Ordinarily it 
is 10-12 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 



and are deeu emerald green in color. The 



numerous chloropl 
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 (o . 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 
Metzgeria 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 grown 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. 3-1 1). Vertical 
sections through any of the marginal indentations which indicate 



180 BOTANICAL GAZETTE [September 



growing points show clearly that its longer 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 
bv a narrow marginal uroiection and each sinus contains two apical 



mam 



cells (figs. 9-1 1). One set carries on 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 



the last cutting one. 



that it strikes the wall of the segment 



more 



to the ventral side (fig. 2). The wall-formation in either 
therefore, shows an obliquity which later is distinctly 1 
horizontal. The primary segment is divided by a vert 



ma 



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. 



the 



dichotomously 



other 



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. Kny 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 



i9i 2] 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. 



asm. anterior to the 



from which the cilia extend, a rounded mass is left at the posterior 
end of the sperm. 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 



the 



sperm 



measurements of the longest sperms 



I the antheridium before it had burst natu 
shed in the field thev have grown somewhat 



Probably 



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 (Leitgeb, 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 



from which 



horizontal 



\~S 



igi2] 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 



6) 



immature 



egg has been fertilized, are carried with the filaments to the 



calypt 



thinks more trichome 



produced on the torus, but this seems unlikely, for many are 
sloughed 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 (Leitgeb 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 



1 84 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 nuclei and 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. 4 2 ) 5 
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. 



i9"] 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 



from the 



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 



52). 



the wall and a broad brown thickening 



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 (i) 
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. Goebel (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 p 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, 0.5 and 1 per cent lactic acid, 
0.3 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 



room with 



that 



roughly with that outside, and the light was kept diffuse by the 
window shade. Sowings were made on sterilized clay, sand, 



m, humus, and sand, and 



Cultures 



on rotten wood were spoiled by Pencillium. Although the pots 
containing the soils were scrubbed, dried, sterilized over night in a 



with 



many became 



This could 



i come about when spores were taken out for examination 
accompanying table records some of the data. 



Sow 


ing 


Final 
examination 


Time 


Medium 


Condition of spores 


March 


23... 


June 23 


3 mos. 


H 2 on cotton 


2-celled to all stages 
(fungi ) 


April 


15 — 


June 17 


2 mos.-f 


clay 


1-3-celled; majority 2- 












celled 


April 


15... 


June 17 


2 mos.+ 


H 2 on filter over 
cotton 


majority 2-celled 


April 


6... 


June 19 


2 mos.-f- 


H 2 on filter over 
cotton 


2-celled 


May 


5... 


June 19 


1 mo. + 


H 2 on filter over 
cotton 


2-celled 


May 


5... 


June 17 


1 mo. 


soil 


2-7-celled (fungus) 


May 


21.. . 


June 21 


1 mo. 


sand 


2-celled 


May 


21.. . 


June 21 


1 mo. 


1% cane sugar filter 
on cotton 


2-celled 


May 


29.. . 


June 21 


1 mo. — 


soils 


1-4-celled (Chaetomium) 


May 


29... 


June 21 


1 mo. 


H a O filter on cotton 


2-celled 


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 in a 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 Amur a 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 p to 90 and 100 fi in 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 



with the development of the 
t in it when present. Where 



spore is that the fungus plays some part in it when present, 
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. 



mu 



rhizoids. In 



ment 



o 



many- 



leafy and some thalloid liverworts (Nemec 20, Bolleter 2, 
Gar jeanne 8, Cavers 5), but only in one case does Garjeanne 



with the 



in anv cell of the sDorelinz (figs. 64-66) and 



the 



hyph 



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 i 

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, 



? 



190 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. 
Gar jeanne has found that more than one species 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 J ungermannia 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 



chloroplasts at maturity 



tonemal 



The 



spore coat incloses the very young sporeling. 



mature 



some 



Infection takes 
taere. 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 John M. Coulter and 
Professor W. J. G. Land, under whose direction this work was done. 

The University of Chicago 



( 






1912] CLAPP—ANEURA PINGUIS 191 



I 



Bryol. 12:104-105. 1907. 
Metzgeria. Ann. Botany 



LITERATURE CITED 

. Beer, R., On the development of spores of Riccia glauca. Ann. Botany 
20:275-291. 1906. 

2, Bolleter, E., Fegatella 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. 

5- , On saprophytism and mycorhiza. New Phytol. 2:30. 1907. 

6, Coker, W. C, Abnormalities in liverworts. 
7* Evans, A. W., Vegetative reproduction in 

24:271-303. 1910. 
8. Garjeanne, F. M. Anton, tJber die Mykorrhiza der Lebermoose. 

Beih. Bot. CentralbL 15:470-482. 1903. 
9* , Die Verpilzung der Lebermoosrhizoiden. Flora 102:147-185. 

1911. 

10. Goebel, K., Archegoniaten studien. 6. Uher Function and Anlegung 

der Lebermoos-Elateren. Flora 80:1-37. 1895. 

11. , tJber die Jugendzustande der Pflanzen. Flora 72: 15-16. 1889. 

12. , Organographie der Pflanzen. 1898-1901. 

13. Hofmeister, 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. 1877. 

15. Kny, L., Beitrage zur Entwickelungsgeschichte der laubigen Lebermoose. 
Jahrb. Wiss. Bot. 4:6497. 1 865-1866. 

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 

112:779-792. 1903. 
18. Le Clerc du Sablon, Recherches sur le developpement du sporogone des 

Ann. Sci. Nat. Bot. VII. 11:126-180. 1885. 
, Untersuchungen iiber die Lebermoose, 1874-1882. Vol. 



Hepatiques. 



III. Die frondosen Jungermannieen 



Lebermoose. Ber. Deutsch. Bot. 



Gesells. 17:311. 1899. 



21. -, Die Wachstumsrichtungen einiger Lebermoose. Flora 96:409- 



906 



J., Studies of irritability in plants: the formative influe 



light. Ann. Botany 20:449-465. 1906. 
Schiffner, V., Hepaticae in Engler 
Pflanzenfamilien 1:1-144. 1893-1895. 



Prantl 



24. Schostakowitsch W., Uber die Reproductions- und Regenerations- 
Eracheinungen bei den Lebermoosen. Flora 79:350-384. 1894. 



192 BOTANICAL GAZETTE [September 



EXPLANATION OF PLATES IX-XII 

* 

Fig. i. — Sketch of dioecious thallus. 

Fig. 2. — Vertical longitudinal section through apical cell; X505. 
Figs. 3-8. Serial horizontal section through apical cell; X830. 
Fig. 9. — Horizontal section of thallus, showing two apical cells; X505. 
Figs. 10, 11. — Horizontal section of thallus showing two apical cells in one 
sinus; X830. 

Fig. 12. — Young mucilage hairs; X830. 

Fig. 13. — Young rhizoid with chloroplasts present; X830. 

Fig. 14. — Young rhizoid infected by fungus from within; X830. 

Fig. 15. — Rhizoids with and without fungus, showing irregular form; 

X175. 

Fig. 16. — Vertical section through antheridium initial; X505. 

Fig. 17. — Vertical section, showing antheridium initial divided into stalk 

and antheridium proper; X830. 

Fig. 18. — Vertical section through antheridium, showing first vertical 

wall; X soS- 
Fig. 19. — Stages of development in antheridium, showing wall and 

spermatogenous cells defined; X505. 

Fig. 20. — Vertical section through antheridium, showing early divisions of 

the spermatogenous cells; X830. 

Figs. 21-24. — Horizontal sections through the antheridium, showing its 

development; X1650. 

Figs. 25, 26. — Vertical sections through older antheridia, showing stalk 

cells, and fig. 26 showing the development of the tissue around the antheridium; 

X505. 

Fig. 27. — Stages of development in the sperm; X2800. 

Fig. 28. — Horizontal section through an archegonial branch, showing 
numerous archegonia; X505. 

Fig. 29. — Vertical section through young archegonium; X830. 

Fig. 30. — Vertical section through older archegonium ; X 830. 

Fig. 31. — Horizontal section through archegonial neck; X830. 

Fig. 32. — Vertical section through mature archegonium; X830. 

Fig. 2,3^ — Vertical section through archegonium, showing canal cells dis- 
organized; X830. 

Fig. 34. — First division of the young sporophyte; X 1040. 

Fig. 35.— The haustorial cell of the sporophyte, well elongated, and 
gametophyte cells disorganizing; X1040. 

Fig. 36. — Haustorial cell more elongated ; the sporophyte proper composed 
of four cells; X 1040. 

Fig. 37. — Foot, seta, and capsule region of the sporophyte marked out; 
X 1040. 



BOTANICAL GAZETTE, LIV 



PLATE IX 













^x.L.Clo^pp del. 



CLAPP on ANEURA 






BOTANICAL GAZETTE, LIV 



PLATE X 




Cc.L.Clapp. 



CLAPP on AXEURA 



BOTANICAL GAZETTE, LIV 



PLATE XI 




Q.LClapp de|. 



CLAPr on AXEURA 



BOTANICAL GAZETTE, LIV 



PLATE XII 




GcLCIa. 



CLAPP on AXEURA 



IQI2] 



CLAPP—ANEURA PINGUIS 



193 



Fig. 38. — The primary wall layers and sporogenous tissue differentiated; 
X 1040. 

* 

Figs. 39, 40. — Older stages of the sporophyte; the cushion of sterile cells 
and sporogenous tissue differentiated; X 1040. 

Fig. 41. — Older sporophyte showing the meristematic region of the 
sporogenous tissue; X505. 

Fig. 42. — Delineation of elaterophore beginning; X505. 

Figs. 43-50. — Young elaters and spore mother cells; X 1650. 

Fig. 51. — Mature spore; X1650. 

Fig. 52. — Occasional form of mature spore; X 1650. 

Fig. 53. — Branched elaters; X830. 

Fig. 54. — Cross-section of capsule, showing lines of dehiscence; X830. 

Fig. 55.— Germinating spore, swollen; X830. 

Fig. 56. — First stage of germination; X830. 

Figs. 57, 58. — The same stages a little later; X1040. 

Figs. 59-63. — Stages in germination; spores developing on wet cotton; 
uninfected by fungi; X830. 



Figs. 64-66. 



fungu 



Figs. 67, 68. — Older thalli showing fungus present in darkened region; 



X830. 



Fig. 69. — One of the larger thalli, developed in capsule shown in fig. 70; 



X830. 



Fig. 70. — Capsule showing thalli from split valves; X830. 
Fig. 71. — Germinating spore without fungus: X1040. 



V 



PLANT GEOGRAPHY OF NORTH CENTRAL 

NEW MEXICO 1 

CONTRIBUTIONS FROM THE HULL BOTANICAL LABORATORY 160 

J. R. Watson 

(with seven figures) 

F i 

The area included in this investigation comprises the northern 

i 

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. 



much 



mesa, which rises 



may 



1 This study was undertaken under the direction of Dr. Henry C. Cowufis. 

Botanical Gazette, vol. 54] 



[i94 



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 ico 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 MacDougal. 2 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 100 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 is a 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 

2 MacDougal, 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. 
0.48 0.33 0.22 0.26 0.69 0.35 1.43 1.07 1.7 0.77 0.46 0.31 

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- 



some 



Jiirsty soil to a sufficient depth to reach the roots. On the 
r hand, much of the summer rain comes down in such a deluge 
a goodly percentage runs off the mesa and especially its foot- 
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 



hills 



months 



mountains 



cally different. Judging from observation, the summer rains are 
about 50 per cent in excess of those at Albuquerque. But while 



higher parts of the mountains 



inter 



storms 



down some distance on the mesa. This snow, slowly melting 

sMagxusson, C. Edw., Bull. Univ. N.M. no. 5. 



■ 



i9i 2] WATSON— PLANT GEOGRAPHY OF NEW MEXICO 197 



thoroughly saturates the soil; much more 



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 



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 

100 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 (Magnusson, loc. cit.), giving evaporation in 

inches, show that the ratio of evaporation to rainfall is more than 
10 to 1 : 

Jan. Feb. Mch. Apr. May June July Aug. Sept. Oct. Nov. Dec. 
2.04 2.63 6.17 6.82 10.08 12.63 n.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; 



(ed 



4 A 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, 5 
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 pinon 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 35.4 

Hymenatherum society of the association. . . .12.7 25.8 



WIND 



A factor influencing the evaporation from plants is wind. 



autumn 



calm 



rms 



man 



walking against it. These violent winds plants must 



may 



the mesa. The prevailing direction of the wind is 



south and southwest. This seems 



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 Magnusson presents the following aver- 

s Livingston, B. E., Relation of desert plants to soil moisture. Bot. Gaz. 50: 
241-256. 1910. 



iqi2] 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. 



mountains the 



the flora of the east would be able to recognize at least the genus 



b luZiV/ "^ ^**^ *•-"*- £> 



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 



i. 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 baithinioides , while on 
the ground grow J uncus balticus, Trifolium Rydbergii, Aster spino- 
sus, and a little grass. This forest is monotonously uniform and 
poor in species. 

2. Juncus-Houttuynia 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 jiuitans 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 
annum, 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) 
Bigelovii, 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 



i9i 2] 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 multi flora, 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 Soli* 
longifolia. It is the tallest shrub outside of the mountains and the 
cottonwood forest, reaching a height 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 <k climbs for 
water and digs for wood." Here grow also two low perennial ever- 
green composites, Berlandiera lyrata and Melatn podium 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, Thelespcrma gracile, and Bailey a mul- 
tiradiata, together with Pentstemon ambiguus, are characteristic. 



202 BOTANICAL 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 10 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 w r ith 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 

the more level ground of the mesa 



stops abruptly at its dissected edge, as stated under the last head- 



ing. This 



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 Gutter- 
rezia (a somewhat shrubby perennial that grows to be 3 ft. high, 
and is often called "goldenrod") as to merit being called a Gutter- 
rezia formation (fig. 1). The seasons of 1909 and 1910 were drier 



July 



most of the remainder 



small 



utumn 



mesa 



those two vears it bloomed onlv in the mountains 



1912] 



WATSON— PLANT GEOGRAPHY OF NEW MEXICO 



203 



the 



trail conserves the moisture after the principle of dry-farming. 



In 191 



summer rains commenced in late J 



that survived are thrifty and show abundant bloom. 



mesa is mono 



miles 



Opuntia fr 
r (Opuntia 



see only a few grasses, Gutierrezia, 
r occasionally a Yucca glauca or a 








..... 




■w. 






- .< ■ »»" 



V- 



MP* 




mg 












**** 



I 



■ 







Fig. i. — The head of an arroyo on the edge of the mesa: in the foreground, 
Guticrrczuu Salsola, and Yucca glauca; to the extreme left a clump of Chrysothamnus 
Bigelovii; in the distance the Guticrrezia association. 

The plants of the mesa belong to three ecological groups. (1) 
Plants like the cacti, Bigelovia, Yucca, Sarcobatus, and Suacda, 
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 in 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 



ous examples in this class are rhacetia 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 



most 



many of the shrubs. W 



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 y Houstonia humifusa, Plantago Purshii, Asclepias 
br achy Stephana, Wedelia incarnata, Russian thistle, and Solanum 
elaeagnifolium. By September 10 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 



stems 



With M 



come the blossoms of the stemless evening primroses (Oenothera 



chimaja (Cymopt 



When J 



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. 



middle of the mesa. 1 z miles 



ping of a layer of sandstone causes a succession of springs to appear, 
and about these springs are cottonwoods, Juncus, Houttuynia y and 
other plants of the valley. In other words, a spring changes Upper 



IQI2] 



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 sDread over the 



mesa 



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. 



Id seems to receive slightly more 
\ the mountains and ascends one 
mouths of the canons, a new ph 




Fig. 2. — At the base of the Sandia Mountains: Opuntia arborescens society; 
Rhus trifoliata 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 



the dominant plant. 



formation of which Juniper us monosp 
East of Albunueraue it is confined 



2o6 



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 




■■i 



*-^W % 



Fig. 3. — Opuntia arborescens in fruit: to the left is an arroyo 

interesting to recall the occasional occurrence of cedars on the lava 



a thousand feet lower. 



ge of this formation 



moisture is evident. 
l the lower limit of 



On the whole, 



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 glanca 
extend into this formation and Opuntia arborescens is abundant 



igi2] WATSON— PLANT GEOGRAPHY OF NEW MEXICO 207 



and characteristic. Other members are Rhus trilobata, Nolina 
texana (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. 6 



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 pinon {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 
parajolius) , Philadelphus micro phyllus, Lesguerella 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 jS iittalliana), wild gooseberry {Ribes divaricatum irriguum), 
Ptelea 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 
pmon formation less than a mile away, than there is between it and 
the woods of Ohio, as witness the preceding genera, if not species. 

W hether 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 dropped. 

7 Report of the N.M. Resource and Conservation Commission. December 101 1. 



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 ft., 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 




Fig. 4. — View toward the south in the Sandia Mountains (about 8500 ft.) m 
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 



igi2] 



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. 



streams 



takes almost entire possession of the soil, forming a quite distinct 



association. 




Fig. 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 



2io BOTANICAL GAZETTE [September 



(Symphoricarpus 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 xerophvtic association in this formation. Furthermore, 



maximum 



more mesophytic places among 



The herbs of this association are also somewhat different. 



folia, Ceanothus Fendleri, Thalictrum Fendleri 
common are Hedeoma Drummondii, Gentiana affi 
Gunnisonii. 



Campanula 



somewhat 



le Manzano Mountains the alligator juniper is common 
chiefly the Pinus-Andropogon association, but having so: 
> of the pifion formation. This would seem to be abc 
hern limit of Juniperus pachyphloea, as it is entirely absc 
J 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, Aphanostephus 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. 



IQI2] 



WATSON— PLANT GEOGRAPHY OF NEW MEXICO 



211 



DOUGLAS SPRUCE FORMATION 



Covering north-facing slopes above 8000 ft. and extending down 
the narrower canons 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- 







■ 










Fig. 6. — In the canon the Douglas spruce association; on the rocky slope the 
Pinus pondcrosa association; in the foreground, white oaks, verbena (in bloom), and 
mountain mahogany; a small red cedar to the right of the rocks in the center. 



folia, Polemonium foliosissi 



Pachystima myrsin ites, Oxalis 



violacea, Prunus demissa, Fragaria, Rosa arkansana, Amelanchier 
ijolia, Hcuchera paroifolia, Sedum Wrightii, Corydalis aurea. 

I pin a) occidentalism Aquilegia canadensis, Stellaria 



Clematis 

Janiesii, and Smilacina stellata. 
Merriam, but nowhere in 
belt around the mountains 



the 



?? 



of 



only 



most mesophytic places, as in the narrower V- 
1 north-facing slooes where snow accumulates 



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. 







Fig. 7. — Top of North Sandia Mountain: Picea Engehnannii; in the foreground, 
Potent Ma, Castilleja, and Aphanostephus. 



most exoosed Dart of North Mountain 



the first are replaced by Engelmann's spruce (fig. 7). This would 



Merriam 



ii 



ma 



meets an occasional Pinus fl< 



CANON ASSOCIATIONS 



Ascending a cafion a very interesting succession of associations 

• 



presents itself. The first tree met approaching 



mountain 



from 



clump 



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 canon 
representatives of the cedar and pinon 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 
canon is open or U-shaped, the yellow pine will occupy the floor 
with the poplar along the stream. Ascending still higher, where 
the canon 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, Pedicular is 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 canon; and pine, pinon, and cedar on the slopes, 
until the ultimate formation of the mesa is reached. 8 



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 

8 A study of Mt. Taylor indicates that the alligator juniper has a place between 
the yellow pine and the pinon. 



214 BOTANICAL GAZETTE [September 



mountains 



doubtless be occupied by Douglas spruce were they situated at 



greater elevation, chiefly 



mountains 



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 cotton woods. The storksbill (Er odium 
cicutarium) grows in the mountain canons 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 9000 ft. 
on steep slopes facing the southwest, and it grows at all altitudes 
between. On a basis of temperature control, this distribution seems 
inexplicable. But these arroyos are the least xerophytic places 

The soil at the depth of a foot or two is always 



mesa 



moist, due to the 



th 



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, 

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 canons were found in full leaf, and their 
blossoms gone; a little higher they were just leaving out and 



ming; at the top of the 



Again 



on October 6 the leaves were still green and vigorous at the base 



iqi2] 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 canon 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 
pinon, the yellow pine being largely omitted. The branches of 
the spruce and pinon 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 canons 
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 canons. 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 canons. 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 
xerophytic. 9 

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 



maintain 



this region. 



am sim 



not on one alone. 



important. Any scheme for mapping "life 
d on all the factors determining the same and 



Valley 



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. Banks 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 

i. 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 pinons will grow with their branches almost 
touching if the roots of the former have access to an unfailing 
water supply. 

v * J? 

c) A spring will change "Upper Sonoran" to "Lower Sonoran. 



i9i 2] 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." 

/) The tendency of the higher zones to creep down the canons 
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 exceedingly 
rapid growth and reproduction. 

9. The differences in amount and distribution of rainfall in 
different years causes a more 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 of New Mexico 

Albuquerque 



THE PERFECT STAGE OF ACTINONEMA ROSAE 1 

Frederick A. Wolf 

I 

(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 s.eason. 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 sub- 
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 oi 
the acervulus in fig. i is shown a cross-section of one of these 
strands. The internal mycelium penetrates the mesophyll of the 

1 Contribution from the Department of Botany, Cornell University. No. H3* 



Botanical 



[218 



19"] 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 



membrane 



There is no 
•vulus. On 



the upper side of this stroma certain cells are formed 



conidia. These conidiophores are not prominently differen- 



form from 



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 oi 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 



2 2o 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. i). 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 18-25X5-6^. 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 formed. 
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, 



i9i 2] 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 



um 



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 3 or perithecia. 4 Frank 5 considered 
them as very flat spermagonia ("des sehr flachen Spermagoniums"). 
Sorauer 6 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 Melaneoniales, as 
exampled by Gloeosporium, Marsonia, etc. Scribner 7 has correctly 
figured the structure of the acervulus and says that while the 
fungus from analogy is placed with the sphaeriaceous fungi, no 
penthecia-like or pycnidial structures have been observed. 

Partly because of the different interpretations of the morphology 

2 Saccardo, P. A., Syll. Fung. 3:408. 1884; also Lixdau, G., Sphaeropsidales 
m Exgler and Prantl's Pflanzfam. 1:369. iqoo. 
3 Lixdau, G.Joc. cit. 

Massee, G., Diseases of cultivated plants. 428. iqio. 

s Frank, A. B., Die Krankheiten der Pflanzen. 621. 1880. 

Soravf.r, Paul, Handbuch der Pflanzenkrankheiten. 406. 1908. 

7 Scribner, F. L., The black spot on rose leaves. Kept. U.S. Dept. Agric. 
366-369. pi s , 8 , 9. d88 7 ) 1888. 



222 BOTANICAL GAZETTE [September 



of this fungus it has been variously named by different workers. 
In 1849 the name Actinonema rosae (Lib.) Fr. 8 was employed. 
In 1853 Bonorden 9 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, Briosi and Cavara 
distributed the species under the name Marsonia rosae (Bon.) 

1 

Br. & Cav. 10 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. 



11 



I have been able to examine the specimens distributed by Briosi 
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. 12 

Saccardo 13 notes that Marsonia rosae (Bon.) Br. and Cav. 
resembles Actinonema rosae (Lib.) Fr. This same fungus was 
described by Trail 14 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. 15 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 16 included two species in the genus Actinonema, 

8 Fries, Elias, Summa veg. Scand. 424. 1849. 

9 Bonorden, H. F., Beitrage zur Mykologie. Bot. Zeit. 282. pi 7. fig- 2 - l8 53- 

10 Briosi and Cavara, Funghi parassiti delle coltivate od utile, n. 97- 1889. 

11 La natura degli acervuli fruitifera, subcutanei 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. 

12 Type material was received through the courtesy of the Bureau of Plant Indus- 
try, U.S. Dept. Agric. I am greatly indebted to Miss Ethel C. Field 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 Saccardo, P. A., Syll. Fung. 10:477. 1892. 

14 Trail, J. W. H., Micromycetes of Inveraray. 46. 1889. 

15 Persoon, C. EL, Mycologia Europaea 1:51-52. 1822. 

16 Fries, Elias, Elenchus Fungorum. 151. 1828. 



iqi2] WOLF—ACTINONEMA ROSAE 223 



A. padi and A. crataegi, the latter showing at length peri 
like structures, but no conidia were observed. In 18 29 17 he em 



5 name 
renomy 



Later 18 he characterized the 



m 



thecium 



and lists A. rosae as one of the 



species which often possesses only a sterile mycelium. Saccardo 19 
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 snores were not observed at that time. The radiating 



mycelium 



em 



character as originally given by Persoon. Lindau 20 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 subcuta- 
neous, as Marsonia baptisiae E. & E., M. panatoniana Berl., and 
M. fructigena (Rick.) Berl. Briosi 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- 
wa/. The Actinonema-like character of the mycelium was not 
taken into account by them as indicative of generic position. 



same 



Marsonia 



e subepidermal acervulus has been made one 
acters of Marsonia, it would seem that these 
might nronerlv be Dlaced in this genus. On 



other 



species of Actinonema. If we accept Persoon's 



' Fries, Elias, Systema Mycologicum 3:266. 1829. 



18 



, Summa veg. Scand. 424. 1849. 



19 Saccardo, P. A., Syll. Fung. 3:408. 1884. 

20 Lixdau, G., Engler and Prantl's Pflanzfam. i:399- l8 99- 



224 ' 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 19 10, 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 or 



igi2] WOLF— ACTINONEMA ROSAE 225 



med 



in a radiating manner, especially noticeable at the margin of the 



shield, 
walls. 



m 



shield varies in diameter 



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 mgjde 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 



formin 



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 



hymenium before the opening of the apotheciu 
is, however, this covering is not so well develop 



may 



opens. It may form a continuous delicate layer over the asci 



shield . 



mature 



.-> 



the 



hymenial layer. Fragments may 



the apothecium or they may disappear. It is only by the elonga- 
( n of the asci and the consequent increase of pressure that the 
tide and shield, together with the upper part of the apothecium, 



manner 



/menium have ruptured 



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. 

1 

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 peritheciurgi 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 70-80X15 /*. 

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 20-25X5-6 /*, 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 hyaline 
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 



made 



and 



germination 



method. Germination occurs within 24 hours, the larger 



more often germinating, althoug 



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 

*d free of everything else. Several series of poured 



remo\ 



from 



sterile, which indicated that no other spores except ascospores of 
the rose fungus had been carried over. The spore 



masses 



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- 
tions 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 21 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. 22 One species of Actinonema, however, has been 
connected with an Asterella, Actinonema rubi (Fkl.) becoming 
Asterella rubi (Fkl.) v. Hohnel. 23 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 24 as a 
subgenus of Asterina for those species which have hyaline spores. 
Later 25 he raised Asterella to generic rank. As Saccardo 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. Lindau 26 thinks the 
existence of this genus is still questionable. Subsequently but 
little investigation has been made on the genus and no clear-cut 

21 See footnote 7. 

"Laubert, R., and Schwartz, Martin, Rosenkrankheiten und Rosenfeinde. 
16-19. 1910. 

2 * Von Hohnel, F., Uber Actinonema rubi Fuckel ist Asterella rubi (Fkl.) v. 
Hohnel. Ann. Myc. 3:326. 1905. 

*4 Saccardo, P. A., Syll. Fung. 9:393. 1891. 

25 , Syll. Fung. 1 : 25 and 42. 1882. 

26 Lindau, G., Engler and Prantl's Pflanzfam. 1:340. 1897. 



1912] WOLF— ACTINONEMA ROSAE 229 

* 

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 
perithecia, 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 

s, 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 Sphaerella. Micro peltis longispora 
Earle, n. 6349, plants of Porto Rico, is entirely superficial. Micro- 
thyriutn littigiosum Sacc, collected at Frankfort, Germany, by 
Dr. Paul Magnus, seems to form superficial perithecia, but the 
mycelium is present in the epidermal cells. Myriocopron 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 so little is 
known of the perithecial development and the method of securing 
food supply of the Microthyriaceae, this family would afford an 



Elli 



230 BOTANICAL GAZETTE [September 



excellent field for investigation. Matre 27 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 a new genus. Because of the two separate structures, the shield 

2 7Maire, R., Les Su^oirs des Meliola et des Asterina. Ann. Myc. 6:124-128. 
fig. 4. 1908. 



19"] WOLF—ACTINONEMA ROSAE 2*1 



o 



and apothecium, the name Diplocarpori* 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, 
100-250 /* 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 
°f Pseudoparenchyma cells, the outer of which are dark brown, 

28 *"-Mos, "double," Kapirbs, "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, 70-80X15 A*, 8-spored; paraphyses 
slender, enlarged abruptly at the tip, often i-septate. Spores 
oblong-elliptical, hyaline, unequally 2-celled,. constricted at the 
septum, 20-25X5-6/*; 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, 18-25X 
5-6 m, 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 /x diam.; scutulo 
atro-brunneolo, subcutaneo, mycelio reticulato insidiente, orbiculare, margine 
plus minusve radioso. Apothecio primo epidermide tecto, demum margine 
scutuli adjuncto, in centra irregulari-stellato dehiscente. Ascis oblongis vel 
subclavatis, supra obtuse angustatis, 70-80X15 ^ octosporis; paraphysibus 
filiformibus, apice incrassatis, interdum i-septatis; sporidiis oblongo-ellipticis, 
inaequaliter bicellularibus, ad septa constrictis, guttulatis, hyalinis, 20-25X5" 
6 fx. 

Hab. in foliis dejectis Rosae sp. 

Status conidicus: Maculis epiphyllis, atro-brunneis vel purpurascentibus, 
fibrillis e centro radian tibus, albido-arachnoideis; acervulis subcutaneis, 
sparsis, nigricantibus; conidiis constricto, i-septatis, guttulatis, hyalinis, 

18-25X5-6 /X. 

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 var. Belle 



i9i 2] WOLF—ACTINONEMA ROSAE 233 



Angevine, Triomphe d'Alenfon, 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 29 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. Halsted 30 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 



the 



compounds. Since 



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 



Note. — 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, 

it is especially important that it be compared morphologically, with the rose 
fungus. 

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 w T ere 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 

29 See footnote 22. 

30 Halsted, 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 

Fig. i. — Acervulus of conidial stage (Actinonema rosae), with a section 
of one of the radiating strands at the right of the acervulus; X400. 

Fig. 2. — Conidia formed free in culture; the two halves are easily sepa- 
rable; germination of the separated cells; X400. 

Fig. 3. — Normal conidia from acervuli, and their method of germina- 
tion; X400. 

Fig. 4. — Surface view of Diplocarpon rosae, showing the shield and sub- 
cuticular strands from which it developed; X no. 

Fig. 5. — Surface view of mature perithecia in which the shield has been 
ruptured irregularly and folded back; X55. 

Fig. 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; X200. 

Fig. 7.— A stage in which the fruiting part of the perithecium has begun 
to be differentiated; the shield and ascogenous stroma are separate; A, young 
apothecium; X200. 

Fig. 8. — Differentiation of the asci within the apothecium; X200. 

Fig. 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. 

Fig. 10. — Perithecium in about the same stage of development as fig. 9, 

but the shield and fertile stroma are completely united; X 200. 

Fig. 1 1 .—Perithecium which is nearly mature; the hymenial covering 
has broken; A, upper part of apothecium; B, shield; C, cuticle; E, epidermal 
cells; X200. 

Fig. 12. — Mature fruit body of Diplocarpon rosae; some of the cells of 
the upper part of the apothecium persist at the margin; X200. 

Fig. 13. — An old acervulus persisting at the side of a perithecium; X 200. 

Fig. 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; X 200. 

Fig. 1 5. — Section through a mature perithecium, showing the manner in 
which the shield is folded back ; X200. 

Fig. 16. — Mature asci and paraphyses; the spores have been discharged 
apically from one ascus; X400. 

Fig. 17. — Ascospores of Diplocarpon rosae; X400. 

Fig. 18. — Germination of ascospores; X400. 



BOTANICAL GAZETTE, LIV 



PLATE XIII 




WOLF on ACTIXOXKMA ROSAE 



i 






UNDESCRIBED PLANTS FROM GUATEMALA AND 
OTHER CENTRAL AMERICAN REPUBLICS. XXXV l 

i 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 
1 mm. 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 certam Rigiostachydis sistere videntur. 

v Panzal, Depart. Baja Verapaz, Guatemala, alt. 1000 m., Apr. 1907, H. von 
Tuerckheim n. II. 17 14. 

vZ l Eugenia (Sect. Auteugenia Niedenzu; \Bijlorae 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 

longi in alabastro erubescentes. Petala punctulata 4.5 mm. longa 



mm 



1 Continued from Box. Gaz. 52:53. 1911. 



2 3Sl 



[Botanical Gazette, vol. 54 



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. 1 100 m., Jun. 1909, Charles C. Beam n. 6226. — Typus in herb. Musei 
Nationalis numero proprio 579586 signatus servatur. 

r^T *V 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. 

i 

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 striati. 
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 0.5 mm. longo exempto orbiculana 
3 mm,-diametralia. Antherae 8 mm. longae 1 mm. latae, appendice 1 mm. 
longa. Flores feminini et fructus desiderantur. — A. pallidae Cogn. proxima. 
V In apricis ad praedium Tttis dictum, Prov. Cartago, Costa Rica, alt. 650 m., 
Nov. 1897, Adolf Tonduz n. 11 535. — In fruticetis apud Las Vueltas, Tucur- 
rique, Prov. Cartago, Costa Rica, alt. 635 m., Apr. 1899, Adolf Tonduz n. 
13007. 

Cucurbitacearum duas species ineditas peregrinas fas mihi sit 
hoc loco describere, nempe: 
yiV\ Anguria tabascensis Donn. Sm. — Folia dimorpha profunde 
bipartita vel trifoliolata. Flores masculini spicati. Calycis tubus 
triente superiore angustatus, dentes elongato-triangulares. An- 
therae breves oblongae submuticae, loculis rectis. 

Glabra. Caulis tenuis striatus suicatus. 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 foliolimi terminale obovatum 10 cm. longum 5 cm. latum 
deorsum attenuatum, lateralia oblonga 9 cm. longa 4 cm. lata intrinsecus excisa 



igi2] SMITH— PLANTS FROM CENTRAL AMERICA 237 



extrinsecus basi rotundata, petiolulis 6-7 mm. longis. Cirrhi compressi 
striati. Pedimculi solum masculini visi striati sulcati 17-25 cm. longi, spica 
4-5 cm. longa. Calycis tubus striatus subcylindricus 10 mm. longus basi 
obtusus, dentes 2 mm. longi erecto-patuli. Petala erecto-patula utrinque 
leviter furfuracea ungue 1 mm. longo atque lato exempto orbicularia 6 mm.- 
diametralia. Antherae 4 mm. longae 1 . 5 mm. latae, appendice minutis- 
sima papillosa. Flores feminini et fructus ignoti. — Ad A. diver sifoliam Cogn. 
floribus arete accedens ab ea foliis longe distat. 

^Ad ripas paludosas fluminis Macayal dicti, Comarca de Tabasco finibus 
Guatemalensibus adjacens, Mexico, Jul. 1889, Jose N. Rovirosa n. 519. 

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 
acuminata minute remoteque spinuloso-denticulata supra bulboso-pilosiuscula 
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 0.5 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. 




fW*£ 



Garya laurifolia Benth., var. quichensis Donn. Sm. — Folia 
nitida integerrima. Inflorescentia masculina densissimiflora, spicis 
corymboso-paniculatis suberectis abbreviatis, nodis et spiciferis et 
floriferis approximatis. 



Frut 



niascuiinis notae 4-6 cm. longae, internodiis 1 cm. non excedentibus. 



mplis 



238 BOTANICAL GAZETTE [September 

Versus cacumen montis haud procul a San Miguel Uspantan siti, Depart. 
Quiche, Guatemala, alt. 1800 m., Apr. 1892, Heyde et Lux, n. 3175 ex PL Guat. 
etc. quas ed. Donn. Sm. 

*YlS$V ' ^ Alloplectus ruacophilus Donn. Sm. — Folia oblongo-elliptica 

vei-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 
interdum munitus ad apicem versus pilosus flavicans. Folia leviter disparia 
papyracea pellucida discoloria supra sparsim paleaceo-strigillosa subtus nervis 
fuscis pilosa ceterum strigillis minutis conspersa 15-20 cm. longa 5-6 cm. lata, 
nervis lateralibus utrinque 6-7 marginem ultra medium attingentibus, petiolis 
pilosis 2.5-5.5 cm - longis ad articulationem glandula sanguinea utrinque 
munitis. Pedunculi 6-1 2-ni 1-3 cm. longi pilosi bracteis sanguineis integris extus 
pilosis lanceolato-ovatis 1-1.5 cm - longis fulti. Calycis sanguinei segmenta 
basi extus pilosa ceterum subglabra, quatuor lanceolato-ovatis 1 . 5 cm. longis 



dimidio angustiore 



mm 



sicut apex nigro-mucronulatis. Corolla erubescens villosa 28-30 

7 mm. lata recta vix ventricosa faucibus haud contracta, lobis 1 . 5 mm. longis. 



mm 



longis atque latis. Disci glandula solitaria. Ovarium ovoideum villosum. 
Fructus ignotus. — Ad A. tetragonum Hanst. et A. Ichthyodermatem Hanst. 
arete accedens differt praesertim corolla. 

vln silvis montis vulcanici Barba dicti, Prov. Heredia, Costa Rica, alt. 
2500-2700 m., Febr. 1890, Adolfo Tonduz n. 1997. — Volcan Poas, Prov. 
Alajuela, Costa Rica, alt. 2400 m., Mart. 1896, John Donnell Smith, n. 6729 
ex PI. Guat. etc. quas ed. Donn. Sm. (Specimina sub A . I chthyodermate Hanst. 

olim distributa.) — Tn silvis ad Achinte \n mnntp 



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 glaber. Folia 18-28 cm. longa 9-14 cm. lata perga- 



nervis 



9-10 



Racemorum 



igi2] 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 26-33 mm - 
longae 13-17 mm. latae integrae reticulato-venosae deciduae. Calyx 20-28 
mm. longae ad tres partes partitus extus puberulus intus glaber irregulariter 
sanguineo-maculatus, segmentis obtusis reticulato-venosis. Corolla tantum 
immatura cognita pubescens. Antherae 5 mm. longae. Disci glandula soli- 
taria. Ovarium cinereo-pubescens oblongo-ovoideum 8 mm. longum. Fructus 
ignotus. — A. macrantho Donn. Sm. quam maxime affinis. 

"In silvis prope Las Vueltas, Tucurrique Prov. Cartago, Costa Rica, alt. 
6 35-~7°o m., Mart. 1899, Adolf 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 
tnente 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. Pedunculus 

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, limbus 

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 

discretis. Disci glandula solitaria acute ovata 2 mm. longa. Ovarium 

ovoideum cum stylo 8-10 mm. longo pubescens, stigmate bilobo. Fructus 

desideratur.— A . strigoso Hanst. affinis. 

In silvis ad Pansamala, Depart. Alta Verapaz, Guatemala, alt. 1250 m., 

Maj. 1887, H. von Tuerckheim, n. 1080 ex PI. Guat. etc. quas ed. Donn. Sm. (Sub 

A. strigoso Hanst. olim distributus.)— In silvis montanis prope Coban, Depart. 

Alta Verapaz, Guatemala, alt. 1350 m., Aug. 1907, H. von Tuerckheim n. II. 
1918. 

Quum 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. 

B. Antherae rotundato-quadratae. 



multifli 



Donn 



240 BOTANICAL GAZETTE [September 



II. Calyx leviter obliquus. 

A. Antherae latiores quam longiores. A. tetragonus Hanst. 

B. Antherae rotundato-quadratae. 
i. 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. 

f Folia in pare aequalia. A. costaricensis Dalla Torre et Harms. 
ft Folia in pare dimorpha. A. metamorphophyllus Donn. Sm. 



C. Antherae oblongae. 
i. Folia peltata. 
2. Folia basi petiolata. 



A . pellatus Oliver 



a. Flores singuli aut fasciculati. A. macrophyllus Hemsl. 

b. Flores racemosi. 

f Bracteae virescentes. A. macranthus Donn. Sm. 

ft Bracteae sanguineae. A. tucurriquensis Donn. Sm. 

III. Calyx basi saccatus. 

A. Calycis segmenta parum inaequalia. 

i. Folia concoloria. A. strigosus Hanst. 

2. Folia subtus vinicoloria. A. oinochrophyllus Donn. Sm. 

B. Calycis segmentum posticum ceteris multo minus. 

i. Pedunculus multiflorus. A. ventricosus Donn. Sm. 

2. Pedunculi uniflori. 

a. Pedunculi bini. A. stenophyllus Donn. Sm. 

b. Pedunculi 4-5-ni. A. coriaceus Hanst. 

^iVl~ to 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- 

centia ceterum albo-maculata supra medium grosse remoteque serrata 10-13 

- cm. longa 4 • 5""5 • 5 cm. lata in eodem jugo parum aequalia, nervis lateralibus 

utrinque 8-9, petiolis 1-2 cm. longis strigilloso-pubescentibus. Pedunculi 

tantum ad rami apicem siti ramulo nascente comitati demum axillares ita 

solitarii evadentes 15-25 mm. longi glabri, pedicellis 7-10 mm. longis glabns, 

. floribus pube moniliformi adspersis. Calycis herbacei valde obliqui segmenta 

. fere sejuncta, antica lanceolata 12 mm. longa, lateralia lanceolato-ovata 14 mm. 



igi2] SMITH—PLANTS FROM CENTRAL AMERICA 241 



longa valde inaequilateralia semicordata, posticum orbiculari-ovatum 10 mm. 
longum graciliter cuspidatum. Corollae luteae tubus 3 cm. longus leviter 
ventricosus parum incurvatus limbi amplitudine subtriplo longior, saccus 
pendulus ellipsoideus 8-9 mm. longus segmento calycino postico semiamplectus, 
os obliquum, lobi breves arcuati. Stamina paulo supra basin tubi inserta 
9 mm. 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 Lim6n, Costa Rica, alt. 200 m., 
Apr. 1895, Adolfo Tonduz n. 9554. 

FwV " Phyllanthus (§ Euphyllanthus Griseb.) leptobotryosus Donn. 

Sm. — Folia inter maxima coriacea nitida oblongo-elliptica utrinque 
acuta, petiolo apice incrassato geniculate 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- 
lars, stipulis nullis. Thyrsi tantum masculini visi 3-1 1 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. 
longis. Calycis 6-partiti segmenta parce pubescentia rhomboideo-ovalia 1 mm. 
longa medio incrassata margine membranacea. Disci glandulae obovatae 
filamenta subaequantes. Antherarum 

Santo Domingo de Golfo Dulce, Comarca de Puntarenas, Costa Rica, 



rimae 



Mart. 1896, Adolfo Tonduz, n. 7332 ex PL Guat. etc. quas ed. Donn. Sm. 
( n - 9937 herb. nat. Cost.). 

T" s Mieronyma 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 8-1 1 cm. longa 3.5-4.5 cm. lata incurvo- vel cuspidato- 
acuminata supra lepidibus albis punctata subtus lepidibus contiguis vel imbri- 
catis rubiginosis obtecta, petiolo canaliculato 2-2 . 5 cm. longo, stipulis deciduis. 
Racemi tantum masculini visi ad apicem ramuli versus conferti paniculato- 
ramosi 5-8 cm. longi, bracteis deciduis, bracteolis late ovatis 1 mm. longis 
acutis. Calyx depresso-campanulatus 1 . 5 mm. altus, dentibus 5 triangulares 






2 42 ' BOTANICAL GAZETTE [September 

minutis. Discus cupulatus 5-partitus extus glaber intus glandulosus pubes- 
cens. Stamina 5, filamentis glabris 1.8 mm. longis, loculis ovoideis 0.3 mm. 
longis. Ovarium rudimentarium exiguum. Flores feminini et fructus 



desunt . 



Muell 



In silvis prope Coban, 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. 



$0\S 



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. 



osum 



foliis nascent ibus 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 12-13 cm. longi, bracteis cito deciduis 
5 mm. longis, inferioribus flores femininos simulque masculinos, reliquis 
tantum masculinos, fulcientibus, pedicellis masculinis quam feminina parum 
longioribus 3-5 mm. longis. Calycis segmenta fere sejuncta oblongo-ovata, 
feminina 2.5 mm. longa 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. longis. Discus masculinus 
villosus, glandulis remotis orbicularibus, femininus glandulis contiguis crenu- 
latis circumdatus. Ovarium subglobosum 2 mm.-diametrale, stylis plerjumque 
bis dichotome partitis. Capsula stellatim pubescens 1 cm. longa, seminibus 

Ad C. hemiargyrium Muell. Arg. accedens. 



mm 



Jul 



von 



\' 



v vO ^"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- 



tubum 



Stamina 



sissima. 



i9 1 2] SMITH—PLANTS FROM CENTRAL AMERICA 243 






Arbor 



ramulis petiolisque glandulosis, novellis complanatis glaucis. Folia alterna 
7-9. s cm. longa 3-4 cm. lata incurvo- vel cuspidato-acuminata margine carti- 
lagineo revoluta glandulis remote minuteque denticulata, petiolo canaliculato 
7-12 mm. longa. Pedunculus communis in axillis superioribus situs vix ullus 
vel usque ad 7 mm. longus, pedicellis 5-7 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 



mm. lato glandis comDactis comDresso-subcubicis 



Petala obsoleta. 



60-85 



mm 



Flores feminini et 



ignoti 



j,Apud pagum Tactic dictum, Depart. Alta Verapaz, Guatemala, alt. 
1550 m., Mart. 1908, H. von Tuerckheim n. II. 2163. 

f i«c?-»" Acalypha (§ Acrostachyae Muell. Arg.) radinostachya Donn. 

Sm. — -Dioica. Folia oblongo-ovata crenato-serrata 3-nervia. Stip- 
ulae lineari-lanceolatae perlonge setaceo-productae. Spica femi- 



2 - 3 . 



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 rotunda ta leviter retusa, suprema conferta, 
petiolo 2.5-4 cm. longo ad apicem glandulis binis oblongis 1 mm. longis 
mstructo, stipulis seta 10 mm. longa computata 17 mm. longis. Spica solum 
feminina nota terminalis sessilis usque ad 32 cm. longa. Bracteae 2 mm. 
longae atque latae acuminatae utrinque glandulis stipitatis minute 
denticulatae. Sepala 3 ovata acuta 1 mm. longa. Ovarium 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, Llanurasde Santa 
Clara, Comarca de Limon, Costa Rica, alt. 300 m., Febr. 1896, John Donnell 
Smith, n. 6849 ex PI. Guat. etc. quas ed. Donn. Sm. 

* Conceveiba (§ Veconcibea Muell. Arg.) pleiostemona Donn. 
Sm. Folia suborbicularia vel orbiculari-obovata abrupte cuspi- 
aata basi rotundata vel retusa. Pedicelli masculini singuli vel 
2-4-m inaequales medio articulati calycem nutantem subaequantes. 
Stamina circiter 50-60. 



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 
concoloria pellucida glandulari-denticulata penninervia 13. 5-18 cm. longa, 
10-13 . 5 cm. lata, cuspide 1 cm. longa obtusa, nervis lateralibus utrinsecus 5-6, 
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 7-1 1 mm. longis, 
antheris ob loculos late separatos latioribus quam longioribus. Flores feminini 
fructusque deficientes. — Affinitas cum C. latifolia Benth. summa est. 

Ad ripas Rio Blanco in fundo Rosario dicto, Llanuras de Santa Clara, 
Comarca de Limon, Costa Rica, alt. 300 m., Jul. 1899, H. Pittier n. i34 2 5- 

^ ^ jpf- 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 5-1 1 mm. longis armata. Folia 
subcoriacea nitida 8-12 cm. longa 3.5-5 cm. lata a basi penninervia, nervis 
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 
femininis paulo latiora. Stamina circiter 12, filamentis confertis capillaceis 
2 mm. longis, antheris demum erectis oblongis 1 . 5 mm. longis. Ovarium 2 mm. 



ngum, stylis 5-7 mm. longis, ovulo 



gnota 



Klotzsch 



spinis inflores- 
theris primum 



reversis recedit. 



Secus viam prope San Pedro Sula, Depart. Santa Barbara, Honduras, alt 
200 m., Maj. 1890, Carl Thieme, n. 5606 ex PI. Guat. etc. quas ed. Donn. Sm. 

Baltimore, Md. 



INFLUENCE OF PHOSPHATE ON THE TOXIC ACTION 

OF CUMARIN 1 

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, 2 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 

1 Published by permission of the Secretary of Agriculture. 

1 Schreiner, O., and Skinner, J. J., The toxic action of organic compounds as 



modified by fertilizer salts. Bot. Gaz. 54 : 3 1-48. 191 2. 
2 4Sl 



[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 2 P0 4 ), which like the 
calcium acid phosphate of the first experiment is decidedly acid 
in reaction; the disodium phosphate (Na 2 HP0 4 ), which is neutral 
toward phenolphthalein; and the tribasic sodium phosphate 
(Na 3 P0 4 ), 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 2 O s +K 2 0+NH 3 ), 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 



grams 



milarly the green weight of 



composed of ma 



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 



46.9 grams, 
gives the resu 
taken as 100. 



These results are tabulated in table I, which also 

terms of the normal culture 



IQI2] 



SKINNER— PHOSPHATE AND CU MARIN 



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 98 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 

£CT OF THE MAINLY PHOSPHATIC, MAINLY NITROGENOUS, AND 
MAINLY POTASSIC FERTILIZERS ON CUMARIN 

Phosphate as monosodium phosphate 



Fertilizers composed of 50 to 

ioo per cent of 



Phosphate 
Nitrate . . , 
Potash . . . 



Green weight 



Normal 



With 10 p. p.m. 
cumarin 



Relative growth (normal 

= 100) 



grams 

39-3 

499 
46.9 



grams 
38.6 

42.O 

41.8 



98 

84 
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 m 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 
experiments 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 i 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 



[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 



Fertilizers composed of 50 to 

ioo per cent op 



Green weight 



Normal 



With 10 p.p.ra. 
cumarin 



Phosphate 
Nitrate . . , 
Potash. . . 



grams 
36.3 

45- 8 
445 



grams 

34- 1 

403 
38.2 



Relative growth (normal 

= 100) 



94 
88 

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 10 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 






Fertilizers composed of 50 to 

100 per cent of 



Green weight 






Normal 



With iopp.m 
cumarin 



Relative growth (normal 

= 100) 



Phosphate 
Nitrate. . . 
Potash . . . 



grams 
37-0 

42.4 
42-9 



grams 

33-9 
34-6 

3 l 7 






91 
81 

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 phosphate, 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 

Bureau of Soils 
Washington, D.C. 



* 






BRIEFER ARTICLES 



ABSORPTION OF BARIUM CHLORIDE BY ARAGALLUS 

LAMBERTI 1 

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 Hadleigh Marsh. 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] 



[250 



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 10 per cent 

solution was used from July 8 to July n, 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 w r ere dug and dried for chemical 
analysis. 

Unfortunately the plants treated with w r ater 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 per cent. 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 w T as poisonous to A ragallus Lamberti, it was decided to use a very 
much more dilute solution and to duplicate the preceding experiment, 
using a o 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 
exception of one day when 14 liters were used. This experiment was 
carried on from August 4 to August 18, inclusive. During this time both 
groups 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 
°f Chemistry. The plants treated with barium chloride showed ash 
52.26 per cent and barium 0.20 per cent. The plants treated with 
^ater 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 i 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 



Chemistry 



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 



iminary experiments 



That plants of Aragallus Lamberti endure barium chloride solution as 

1 . • 



with 



is distinctly poisonous. Grouping the analyses, we find that the 



amount 



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. 
D wight Marsh, Bureau of Plant Industry, U.S. Department of Agriculture. 



CURRENT LITERATURE 



BOOK REVIEWS 
Lotsy's textbook 

The first part of the third volume of Lotsy's Vortrage iiber botanische 
Stammesgeschichte 1 begins with the Coniferae and ends with Casuarinaceae . 
There are 1055 pages and 661 figures, scarcely any of which are original. The 
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 



summary 



principal conclusions, but a few points might be noted. 



finds 



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. Lotsy 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 



dicotyledons 



primitiv 



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 Lotsy's own preparations 
would show the boundary of the embryo sac between the free nuclear portion 
and the so-called antipodal region. 



Miss 



igarding 



x Lotsy, J. P., Vortrage iiber botanische Stammesgeschichte, gehalten an der 

Reichsuniversitat zu Leiden; ein Lehrbuch der Pflanzensystematik. Dritter Band: 

Cormophyta Siphonogamia. Erster Teil. 8vo. pp. 1055. Jigs. 661. Jena: Gustav 
F^cher. i 9 „. Jf 7 . 14 . 



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 

originality is not to be expected. There is a general index and an index of 

plant names. Many references to literature are given in the text, but the 

complete bibliography will be deferred until the work is complete. — Charles 

J. Chamberlain. 

MINOR NOTICES 

Forestry in Indiana. — The annual report of the Indiana State Board 
of Forestry 2 for the past year contains two papers of more than usual interest . 
The shorter, by Stanley Coulter, contains a valuable mass of data on th e 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. 

The longer article, by C. C. Deam, the secretary of the board, is an illus- 
trated descriptive list of the tree species native to the state and occupies 270 
pages of the report. Excellent botanical descriptions of some 125 species are 
supplemented by full-page drawings of leaves and fruit, together with notes 
upon the economic uses and horticultural value of the trees, making it a 
valuable handbook of the forests of the state. — Geo. 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 
clearly and compactly under the categories of vegetative organs, spore-producing 



3 Eleventh annual report of Indiana State Board of Forestry for the year 191 1. 
pp. 372. pis. 133. Indianapolis: Wm. B. Burford. 1912. 

3 Stiles, Walter, The Podocarpeae. Ann. Botany 26:443~5 I 4- M s * 8t P Is ' 
46-48. 191 2. 






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. 

Gibbs^ 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 
strobilus organization is traced from Abietineae, through Mkrocachrys and 
Dacrydium, until it reaches its extreme expression in Podocarpus, in which 
genus, therefore, we are dealing with a much modified cone. Many details of 

structure are given which add materially to our knowledge of this interesting 
genus. 

Stiles* published a brief note on the gametophytes of Dacrydiutn 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 Duthie 6 has investigated the anatomy of Gnetum africanum, 
a climbing species. Details are given of the structure of xylem, phloem, pith, 
medullary rays, cortex, latex tubes, epidermis of stem, cork, and leaves. 

Pearson? has investigated three species of Gnetum (G. scandens, G. 
africanum, and G. Buchholzianum) , the study of the microsporangium and 

4 Gibbs, L. S., On the development of the female strobilus in Podocarpus. Ann. 
Botany 26: 5 i 5 - 57I . pis. 49-5 3- 1912. 

s Stiles, Walter, A note on the gametophytes of Dacrydium. New Phytol. 10: 

342~347. figs, 4. jq II# 



602. ph. 57 - 5Qm IQI2 



Anatomy of Gnetum africanum. Ann. Botany 26:593 



7 Pearsox, H. H. W., On the microsporangium and microspore 
with some notes on the structure of the inflorescence. Ann. Botany 
fi&- 6. ph. 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 
Gnetum Gneman, 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. 

Miss Gordon 8 has 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. 

Wieland 9 has 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. An account 
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 
Wieland sees emphasized his contention that the angiosperms have been 
derived from the Bennettitales. 

The same author, 10 in continuing his studies on the trunks of Cycadeoidea, 
has discovered that some of the supposed young strobili are mature ones of 
reduced type. This incidentally disturbs some of the previous conclusions as to 
relationships among the species of Cycadeoidea, and especially extends our 
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 Saunders 11 has developed a scheme which allows a consistent 



8 Gordon. Marjorie, Ray tracheids in Sequoia sempervirens. New Phytol- 
11:1-7. Jigs. 7. 191 2. 

9 Wieland, G. R., On the Williamsonian tribe. Amer. Jour. Sri. 32:433-466. 
Jigs. 18. 191 1. 

10 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* K« x 9 12 - 

11 Saunders, Miss E. R., Further experiments on the inheritance of "doubleness 
and other characters in stocks. Jour. Genetics 1:303-376. pis. 2. Jigs. 2. 1911. 



igi2] 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 doubleness, namely, " »0-rf-singles " which breed true to single- 
ness when selfed or crossed with others of their own kind, and " (/-singles ' ' 
which when similarly bred always produce both singles and doubles, the 
doubles being generally in excess of the singles. Reciprocal crosses between 
(/-singles and w(?-(/-singles give unlike results, owing apparently to a dif- 
ference in the genotypic constitution of eggs and sperms in the (/-singles, 
the eggs being of two sorts while the sperms are all equal. Doubleness is 
recessive and disappears in the F I} but when the ^-single is the seed-parent 
the Fj singles are of two sorts, some breeding true to singleness, others pro- 
ducing both singles and doubles. When the (/-single is the pollen-parent, 
the Fj singles are all of one kind and all give both singles and doubles in F 2 , 
The ratios of singles to doubles in the pure-bred (/-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 F, the absence of one or both of these resulting in doubleness. 
If these two factors were independent, the expected ratio would be 9 singles to 
7 doubles, but if they are coupled according to the scheme discovered in sweet 
peas, etc., n— 1:1:1: n— 1, the doubles would be in excess of the singles as 
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 F are carried by the 
pollen, and the coupling can show itself only in the constitution of the eggs. 
The crosses with ^-(/-singles resulted in an unexpectedly small number of 
doubles in F 2 , owing, as proved by further breeding, to the fact that in the 
^-(/-single race singleness is not produced by the joint action of X and F, 
but of a similarly coupled pair X' and F\ To further complicate the situa- 
tion, there occurs a " sulfur-white" (/-single race in which the plastid-color 
is also " eversporting " in a manner quite similar to doubleness, the pure-bred 
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 
is coupled with one of the factors for singleness, either X or F. Although in 
the pure (/-single strains X, F, and W are carried only by the eggs, crosses 
between (/-singles and no-d-singles of different plastid-color produced heterozy- 
gous F x plants in which both pollen and eggs carried the coupled series of 
genes. 



258 v 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 
typically unbranched plants will develop some branches when the terminal 
bud is injured. Notes are also appended regarding the inheritance of several 
sap-colors, 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. 12 The work is divided into two parts, the first dealing with 
the biology and the second with the taxonomy of the genus. 

In Part I the biology of the genus is discussed under the following general 
heads: Introduction (including the life history, general characteristics, and 
nuclear phenomena), distribution and relationships, experimental investi- 
gations of life histories, and pathological and economic importance. Particu- 
lar attention is given to the geographical distribution of the species with 
reference to the distribution of their hosts. The main facts are arranged in 
convenient tables. The forms associated with the two sections of Juniperus 
present 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 land 
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- 



13 Kern, Frank Dunn, A biologic and taxonomic study of the genus Gymnospo- 
rangium. Bull, N.Y. Bot. Gard. 7:392-494. 191 1. 



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 Juniper us 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 Potneae, the work of recent 
years has shown that one form has aecidia on Gillenia (Porter anthus) of the 



Fendlera 



bermudian 



Part II comprises the systematic treatment of the genus, 40 species being 

• 1 »«•*«•.•.««•• mm 



recognized 



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 teliai phase. Gym- 
no sporangium fraternum, G. juvenescens, and G. efiusum are described as new, 
and the aecidial hosts of three species are reported for the first time. The 



taxonomic 



fungu 



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 
and colors of the roots has long invited the attention of experimental 
breeders, but the very abundance of material has doubtless acted as a deterrent 
to genetic investigation. Kajanus 1 * 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 (L z and L 2 ) which produce an 
elongation of the roots, two (A t and A 2 ) which cause the roots to be taper- 
pointed below, an inhibitor (B) which opposes the action of the elongation- 
genes, 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 2 . 
In most of the reported crosses the results run fairly close to these ratios, but 



6: 137-179. ph. 9. figs. 2. 1911. 



Genetische Studien an Beta. Zeits 



61:142-149. ig I2 . 



Mendelistische Studien an Ruben. FCihlings Landwirthsch. Zeitg. 



-, Genetische Studien an Brassica. Zeitschr. Ind. Abst. Vererb. 6:217- 



2 37. pis. 4. 1912. 



260 BOTANICAL GAZETTE [September 



when so many determiners affect the same character, the F 2 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 2 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 (Li and L 2 ). Here again 
the evidence for these two genes is the appearance of the long and round 
forms in the F 2 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, 
rose and yellow, etc., showing its compound nature. Some of the color- 
ratios are approximately 15:1 and others 3:1, which are also interpreted as 
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 2 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. — Geo. H. Shull. 

Inheritance in wheat — Nilsson-Ehle 1 * gives a further report on his long- 
continued experiments in the crossing of wheat varieties, dealing this time espe- 
cially with the density 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 (£1 and L 2 ) 

** Nilsson-Ehle, H., Kreuzungsuntersuchungen an Hafer und Weizen. II- 
Lunds Universitets Arsskrift. 7:no. 6. pp. 84. 1911. 



19"] CURRENT LITERATURE 261 



promote elongation of the heads, while the third (C) acts as an inhibitor which 
checks the longitudinal development of the heads. When all of these factors are 
absent, a moderately dense head results, as exemplified by the " squarehead " 
varieties. When C is present and both L% and L 2 are absent, the extremely 
dense "compactum" form is produced. Although considerable transgressive 
fluctuation renders the analysis doubtful in individual cases, the total result 
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 hybrid 
progenies which have seemed to breed true to characters intermediate between 
the parents, and it also explains the intensification of parental characters in 
F 2 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 t L 2 and clj 2 , produces some F 2 plants with very dense heads 
{Chl 2 ) , and some with very lax ones (cLiJU) . In respect to rust-resistance, the 
difficulties of analysis are still greater and the author makes no attempt to 
identify particular genes, but the results of a large number of tests in second 
and third generations show very clearly two important facts, namely, that there 
is a segregation of different grades of resistance in the F 2 , 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 Nilsson-Ehle's crosses was there an indication of a 
simple monohybrid ratio (3 : 1) for rust-resistance, as was found by Biffen. 

Ka janus 1 * reports an instance in which the spelta-chamcter (zigzag rachis 
and adherent glumes) is recessive to the zw/gare-character (straight rachis and 
free glumes), a situation exactly the reverse of that found by von Tschermak. 
This indicates that there are two genotypes of one or the other of these two 
phenotypes, thus paralleling the now frequently demonstrated existence of 
dominant and recessive whites. Kajanus 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 involved. 

Geo. H. Shull. 

Cytology and sexuality of Olpidiopsis. — Overcoming considerable 
difficulties in the matter of obtaining and managing material, Barrett 16 has 
greatly increased our knowledge of the cytology and especially of the sexuality 
of the submerse chytrids. Three species of Olpidiopsis, parasitic on Sapro- 
legnia and Aphanomyces, were studied, two of which (0. vexans and O. luxurians) 
are described as new. The first Dart of the DaDer consists of biological 



observa 



will 



taking similar work. The zoospores are shown 



1$ Kajanus, B,, Zur Genetik des Weizens. Botaniska Notiser 191 1 : 293-296. 

16 Barrett, J. T., Development and sexuality of some species of Olpidiopsis 
(Cornu) Fischer. Ann. Botany 26: 209-238. pis. 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 six in 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 ioo. 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 
primitive 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." — Robert F. Griggs. 

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. Birge 17 has found 
that any damage resulting to the supporting tree must be due to interferenc i 
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 ot 
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 



** Birge, Willie I., The anatomy and some biological aspects of the "ball moss, 
Tillandsia recurvata L. Univ. Texas Bull. 194. pp. 24. pis. 10. 191 1. 



>> 



i9i 2] 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 T. 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 

characteristic of most monocotyledons. The dispersal of the 



typ 



inteeument 



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.— Geo. D. Fuller. 

Permeability. — 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. 
Kuster 18 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. 



penetrat 



cells in their natural conditions, Kuster used twigs of some size, or at least 
whole leaves with petioles. The cut ends were placed in aqueous solutions of 



xyl 



living 



along the xylem strands. A number of anilin dyes that former workers have 
pronounced incapable of entering living cells Kuster 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 
Hober on animal cells, show, with few exceptions, a general parallelism 
between high diffusibility (non-colloidality) 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- 



Jahrb. Wiss. Bot. 50: 261-288. 191 1 



\ufnahme von Anili 



264 BOTANICAL GAZETTE [September 



tion has been given thus far to the invisible chemical composition of v zygotes 
in the generations following a cross. Pearl and Bartlett 19 have investi- 
gated a cross between a yellow dent starchy maize and a white sweet maize, 
and reach the conclusion that low fat content, low protein content, low ash 
content, and perhaps also low crude fiber and low percentage of pentosans, 
are inherited as Mendelian unit-characters independent of the units which 
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- 
tural Experiment Station. — Geo. H. Shull. 

Transition from root to stem. — Compton 20 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 Chauveaud which Compton 
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. — Soueges has undertaken the 



mbry 



with 



« The 



four most recent papers in the series 22 continue the consideration of the 



Myosurus 



It is 



interesting to have the embryogeny of this form so thoroughly worked out and 



so well illustrated. — J. M 



** Pearl, R., and Bartlett, J. M., The Mendelian inheritance of certain chemical 
characters in maize. Zeitschr. Ind. Abst. Vererb. 6: 1-28. fig. 1. 191 1. 

30 Compton, R. H., Theories of the anatomical transition from root to stem. 
New Phytol. 11:13-25. fig. 1. 191 2. 

21 Bot. Gaz. 51:480. 191 1. 

23 Soueges, E., Recherches sur PembryogSnie des Renonculacees. Bull. Soc. 
Bot. France 58:542-549, 629-636. 1911; 59:23-31, 51-56. 1912. 



Vol. LIV 



No. 4 



THE 





October 1912 



Editor: JOHN M. COULTER 






CONTENTS 



m 






Comparative Anatomy of Dune Plants 



Anna M* Starr 



Parnassia and Some Allied Genera 



Lula Pace 



the Microsporangia and Microspores of 



Abutilon 



V. Lantis 



Briefer Articles 

Artificial Production of Aleurone Grains 



W. P. Thompson 



Current Literature 



The University of 




Press 



CHICAGO, ILLINOIS 

Agents 
THE CAMBRIDGE UNIVERSITY PRESS, London and Edinburgh 

WILLIAM WESLEY & SON, London 

TH. STAUFFER* Leipzig 
THE MARUZEN-KABUSHIKI-KAISHA, Tokyo, Osaka, Kyoio 



m 



<* 



Ghe 



Botanical (Sajette 



/ftontbis 



Edited by John M. Coulter, with the assistance of other members of the botanical staff of the 

University of Chicago. 

Issued October 15, 1912 



VoL LIV 



CONTENTS FOR OCTOBER 1912 



No- 4 



COMPARATIVE ANATOMY OF DUNE PLANTS. Contributions from the Hull Botani- 



cal Laboratory 161 (with thirty-five figures). Anna M. Starr - 



- 265 



PARXASSIA AND SOME ALLIED GENERA (with plates xiv-xvn). Lula Pace 



- 3 06 



DEVELOPMENT OF THE MICROSPORANGIA AND MICROSPORES OF ABUTILON 



THEOPHRASTI (with twelve figures). V. Laniis 



- 33° 






BRIEFER ARTICLES 



Artificial Production of Alettrone Grains (with one figure). W. P. Thompson - 3S^ 



CURRENT LITERATURE 

NOTES FOR STUDENTS 



339 



The Botanical Gazette is published monthly, f The subscription price is 7.00 per year; the price 
of single copies is 75 cents. ^Postage is prepaid by the publishers on all orders from the United States, 
Mexico, Cuba, Porto Rico, Panama Canal Zone, Republic of Panama, Hawaiian Islands, Philippine 
Islands, Guam, Tutuila (Samoa), Shanghai. ^[Postage is charged extra as follows : For Canada, 35 cents 
on annual subscriptions (total $7*35), on single copies, 3 cents (total 78 cents); for all other countries in tnc 
Postal Union, 84 cents on annual subscriptions (total $7.84), on single copies, 1 1 cents (total 86 centsj- 
f Remittances should be made payable to The University of Chicago Press, and should be in ^^8° or 
New York exchange, postal or express money order. If local check is used, 10 cents must be added or 
collection. 

The following agents have been appointed and are authorized to quote the prices indicated: 
For the British Empire: The Cambridge University Press, Fetter Lane, London, E.C., and VVlllI fv 
Wesley & Son, 28 Essex Street, Strand, London. Yearly subscriptions, including postage, £1 l**< ° ' 
each; single copies, including postage, 35. 6d. each. . 

For the Continent of Europe: Th. Stauffer, Universitatsstrasse 26, Leipzig, Germany. Yearly su 
scriptions, including postage, M. 3^ each; single copies, including postage, M. 3.60 each. 

For Japan and Korea: The Maruzen-Kabushiki-Kaisha, 11 to 16 Nihonbashi Tori Sanchorae, i0 *£[| 
Japan. Yearly subscriptions, including postage, Yen 15,75 each; single copies, including postage, 
1.75 each. , . •* 

Claims for missing numbers should be made within the month following the regular month ot pu 
cation. The publishers expect to supply missing numbers free only when they have been lost m tr ^ ns 
Business correspondence si Id be addn 1 to The University of Chicago Press, Chicago, 1H- 
Communications for the editor should be addressed to him at The University of Chicago, Chicago, ^ 
Contributors re requested to write seu rc and proper names with part ilar care, -to use the ^ 
system of wt- hi easures, and in citations to follow the fore jhowa in the pages of the Botan 

Gazette. . tfee 

Papers in exces of tl ty-two printed pages are not accepted unless the autb is liog to P a ? , 
cost of t a litional pages, in which case the umber of pages in the volume is correspondingly inc ^ ^ ^ 






Illustrations are furnished without cost to author only when suitable originals are suppnea. - rv 
of the si >ns made in the January number, 1907, will be sent on application, it is ad visa 

confer w he editors as to illustrations requ red in any article to be offered. Vinal 

Separates, if desire must be ordere in advance ot mblica >n. Twenty-five separates ot ong^^ 
art ies without c ers will be supplied gratis. A table show g approximate cost of additional sepa 
is printed on an rder blank which accompanies the proof; a copy will be sent on reque 



Entered Aug* 21, 1896, at the Post-office at Chicago, as sect l-dai 



*** r 



ader Act of Cong 



J 



Mai ^79 



M 



■ 












^P^B^M 1 



VOLUME LIV 



NUMBER 4 



THE 



Botanical Gazette 



OCTOBER igi2 



COMPARATIVE ANATOMY OF DUNE PLANTS 

CONTRIBUTIONS FROM THE HULL BOTANICAL LABORATORY l6l 

Anna M. Starr 

(with thirty-five figures) 

The literature 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 Cowles (8) published the results of his studies of the 
sand dunes of Lake Michigan, describing the general features of 

265 



266 BOTANICAL GAZETTE [octob 



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 



him and to all the members 



me with criticism 



those who aided me 



HOLTZMAN 



access to his paper. 



my 



from the vicinitv of Miller 



from the Indiana dunes, chiefly 

p Part nr\c\ Fiirnessville. The 



mesophytic forms came mainly from the flood plains of the 
Desplaines River at Riverside; some were collected in other meso- 



came from 



Mississipp 



formalin 



microtome. The leaves that made 



most successful permanent preparations were killed with corrosive 
sublimate dissolved in 95 per cent alcohol, used hot. These were 
easily sectioned in paraffin. I found 8 /x the most satisfactory 
thickness. Free-hand sections were also made. Safranin and 



in stammer, lhe names 



Gray's Manual and differ therefore at times 



from those 



made 



half in reproduction. 



magnified 



Ecological factors in the dunes 



Light and heat.— There is direct illumination, increased by 
ection from the sand. Because of the scanty vegetation and the 
at exposure, the temperature of the air is higher in summer and 

s. Owing to the 



than 



high conductivity of sand, the same great diverj 
extremes is present in the temperature of the soil. 

Wind.— Cowles considers this the most potent factor in 
determining the character of the dune vegetation. The winds 



i9i 2] 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. 

Soil. — 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. FlTLT/RT? ll*\ VmQ fnnnH 



this to be more 



wilting coefficient 

BlOTIC FACTORS. 



marked 



the 



they are once established, humus and shade. Humus 



the 



number of soil organisms, toxicity, and aeration. Shade influences 
the germination of seeds and increases the accumulation of humus 



humid 
n the < 



Fuller 



pine 



and in the beech-maple forest 8 cc, a descending scale from the 
pioneer 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; 
w ater-storage tissue about the bundles ; stomata on both surfaces ; 
conductive elements not well developed. Stem with epidermal 
walls thickened all 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 
9-12 ^ on the upper surface and 15 p 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 
bundles; 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 la 



ma 



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 6-1 1 /*; stomata sunken one-half the depth of the 
epidermal cells. Stem with pith rapidly reduced after the first 



almost 



masses 



matous; considerable cork. 



Cirsium Pikheri. — 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, 



masses 



fibers; rays wider than the bundles, the cells with thickened 
outer cells of cortex collenchymatous. 



j 



i9i 2] STARR— ANATOMY OF DUNE PLANTS 269 



Lathyrus maritimus. — A smooth 



Leaf 



almost half of the m 



compact; fibers above and below the bundles. Stem 



sharply angled; phloem 



chyma ; a 



ma penetrating a distance 



medullary rays thin; outer wall of epidermis 



6.2 p. Root with large vessels; about one-half the pith made 
of scattered masses of sclerenchyma. 

Ammophila arenaria. — A stout perennial grass with firm ere 



mor 



ing rootstocks that anchor the dunes, 
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 y* thick, the cuticle 3.2/*. 
Stem with cortical tissue sclerenchyma tous, 
slightly thickened all around. 

Andropogon sco partus (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; 



rmis 



masses 



and below 



the mi 



ones; chlorenchyma above the bundles; outer wall 9.3 /*; cuticle, 



thick 



sunken 



Calamovilfa longifolia. — A rigid perennial 



lower surface plane; 



sheaths 



^ 



Leaf with 
ns on the 



thick 



Ammophila; walls of epidermis 



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 ft; chlorenchyma above 
and below; water-storage tissue in 



the center; chlorenchyma above 
scarcely palisade-like, but of two 
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. 

Lithospermum 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 fi 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 f*; cuticle thick; scleren- 
chyma below the bundles; whole mesophyll composed of compact 
tissue; no palisade; crystals frequent. 




Fig. i. — Solidago racemosa Gill- 
mani: section of leaf. 



1912] STARR— ANATOMY OF DUNE PLANTS 271 



Opuntia Rafinesqui. — Stem 



outer 



wall of epidermis 8/* thick, cuticle 2.4/*; several hypodermal 
layers of small heavy- walled cells; the chlorenchyma composed 



many 



stem 



difficult 



dry it out even with heat and pressure; vascular system poorly 
developed; walls of the elements thin. 



Shrubs 



pumila 



directions 



and thus important in helping to make dunes stationary. Leaf 
thick, 216 /*-; 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 



elements 



the 



lower cells of mesophyll 



palisade-like; crystals, oil, and other deposits abundant. Stem 



numerous 



small lumen; groups of sclerenchyma in the cortex; cork thick. 
Salix syrticola.~A shrub with the same habits as Prunus pumila 



with 



ermis 



ma 



epidermis on both sides; two layers of palisade next the 



epidermis and three more 



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 collenchyma tous; three rows of mechani- 



m 



Hudsonia tomentosa.—A bushy, heathlike shrub. Leaf small, 



the 



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 v> 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. 




An erect 



thick 



in diameter. 

Juniperus communis ( 
evergreen shrub. Leaf 
vex on one side, concave on the other 
which is the morphological upper side 
and is most protected when the leaves 



Fig. 2. — Juniper its com- 
munis: section of leaf. 



stem; stomata on 



this side at the 



cells, guard cells with thickened 



outer and side walls of 



ermis thick 



n-13/i with cuticle 3.2^; hypodermis 



heavy; resin duct on convex side. Stem with a 
and heavy wood cylinder; 13 years' stem 4 mm 



cork thick. 
Junip 



virginiana. — -A shrub or small tree. 



Leaf awl- 



shaped; outer wall of epidermis very heavy, 9.6 /*, cuticle 4.8 ^; 



hypodermal 



thickened 



stomata on upper plane surface, the 



protected side when the leaf is appressed. 



mass 



almost 



stem 4 . 5 mm 
thick. 



h; n growth rings in a 
rows of sclereids in the cortex; cork 



IQI2] 



STARR— ANATOMY OF DUNE PLANTS 



*73 



Hypericum Kalmianum (fig. 3). — A bushy shrub. Leaf re vo- 
lute, thick, leathery; outer wall of epidermis 4.8 /*, cuticle 2.4 ^, 
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 




Fig. 3. — Hypericum Kalmianum: 



having 



section of leaf. 



ma 



surface; sclerenclr 

above and below collenchymatous; 

papillate; outer wall of upper an 



midrib: cells 



mi 



thick 



I lower epidermis thickened, 
Stem with pith star-shaped; vessels 
lumen : medullary rays narrow, pith 



matous; an irregular band of fibers in the cortex. 



Summary of xero phytic characters 

The true dune plants have the following characteristics, which, 
th the excention of thp rhanrtm of the. conductive svstem. are 



admitted 



Habit 



in 



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 (Ammophila, Calatnovilfa). 

Leaf. — 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, Calatnovilfa, 
Lithospermum, Hypericum, Euphorbia poly gonif olid) ; succulent 
(Cakile, Euphorbia poly gonif oli a, 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 poly gonif olia, 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, Junip- 
erus communis, /. virginiana, Pinus Banksiana, Hypericum, 
Quercus y 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)'; stoma ta sunken (Arte- 
misia, Ammophila, Calamovilfa, Hypericum, Euphorbia polygoni- 
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 poly gonif olia) . 

Anatomy of stem. — Succulent (Opuntia)) conductive tissue 
well developed, with vessels large (Cirsium, Lithospermum, Prunus, 
Hypericum, Quercus), with vessels numerous (Salix syrticola, 
Prunus pumila) ; mechanical tissue present, an abundance of wood 



1912] STARR— ANATOMY OF DUNE PLANTS 275 



fibers giving general "woodiness" (Euphorbia polygonifolia, Arte- 
misia, Cirsium, Lithospermum, Prunus, Salix syrticola, Hudsonia, 
Arctostaphylos, Finns, Hypericum, Juniperus communis, J. 
virginiana, Quercus), as sclerenchyma (Artemisia, Lathy r us, 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). 

Anatomy 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. 

Fitting (ii) 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. Comparison 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 
14 cm. 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. (i4 2 Xo.7845-f-8). Since the magnifica- 
tion used was 100, the area examined was o. 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 Cu for 
cuticle. The percentages are of the entire thickness of the leaf. In 
the table of stems N 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 5, 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 H> 
is omitted after the first, as is also the per cent sign. 



1912] 



STARR— ANATOMY OF DUNE PLANTS 



277 



Trees 



T... 
UE.. 
P.... 



Sp.. . 
LE.. 
OW.. 
Cu.. 







ACER SACCHARUM 






Leaf 






■ 


M 




X 




M 


75 M- (69-93) 




!°3 M (95-109) 


N. .. 


41 


10.5 =14 per cent 


13 =12 per cent 


D... 


36 


2 9-5 =39 




40 =39 


W... 


3 


29.0 =39 




40 =39 


F.... 


4-2 


6.0 = 8 




10 =10 


JL/« ■ . • 


6.2 


1.6 

1 "1 • 




3-5 


iv . . . 


3-5 


thin 




i-7 


v>« • • ■ 


80 



s.. 



• • 



64 



Stem 



«(5o) 



X 

33 

37 m(46) 

3-5 
4-7 

8.5 
2-4 

72 
50 



X.— Hairs on lower surface ; upper In 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. 



midrib 



greater 



development of bundles; cuticle on 
upper surface more strongly ridged. In 
both stomata on lower surface only. 



T... 

UE.. 
P.... 



Sp 

LE... 



Cu. 



• • 



Leaf 



M 

OS M (87-72) 

13 = 

14 = 



20 per cent 



22 



2 4 =37 
14 = 



21 



OW... 0.7 



very thin 



CELTIS OCCIDENTALIS 



X 

I20M (104-I44) 

24 =20 percent 
43 =36 
40 =33 



13 



11 



3 

0.7 



Stem 



M 



N. . . 17 



X 



18. s 



D... 74 m(ioi) 74 n (120) 
W... 2.4 



F. • . . 4-8 

Li. . . • 4 ■ O 

R. .. 7 

V^ . . . . ^\.<J 

S. . . . 64 



3-2 

6.4 
32 

7 



32 
80 



A.— -Large glandular cells frequently X— A straggling shrub, probably var. 

occupying the place of the epidermis and pumila; slightly greater development of 

pahsade; 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 
development 



Figs. 4 and 5. 



of vascular elements. 



tracheids; cork thinner; more scleren- 
chyma in the cortex. 



278 



BOTANICAL GAZETTE 



[OCTOBER 



PRAXINUS AMERICANA 



Leaf 



Stem 



M 

T 142 ^ (124-159) 

UE. . . 11 = 8 per cent 



X 

l62 fJL (l42-l87) 

= 9 per cent 



P 



Sp.. . . 



52 
68 



LE. . . 11 = 

OW... 1. s 

Cu. . . 0.7 



36 

48 

8 



14 
68 



42 



59 =36 
21 =13 

3 

1.8 



N.. 
D.. 
W.. 
F... 

R.. 



M 

22.5 



X 

19s 



53 M(87) 51 m(72) 



3-7 

3-2 
7.2 



3-9 
4-5 
7-3 



88 
S3 



no 
99 



3-5 



1-2 



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 long hairs In both walls of pith-cells thickened with 
(ilf smooth); all tissue more compact; conspicuous canals, and outer cortex 
palisade deeper, tending to develop four collenchymatous, features pronounced in 
rows (M only two); vessels in the mid- X. 
rib more numerous but not larger; walls 
thicker; greater development of fibers 
about the stele. Both have conspicuous 
glands on the upper surface, and stomata 
on lower surface only. — Figs. 6 and 7. 





6 



4 





5 



7 



Figs. 4-7.— Figs. 4 and 5, Celtis occidentalis: sections of leaves; fig. 4, mcsophytic 
form; fig. 5, dune form; figs. 6 and 7, Fraxinas americana: sections of leaves; fig. "> 
mesophytic form; fig. 7, dune form. 



IQI2] 



STARR— ANATOMY OF DUNE PLANTS 



279 



JUGLANS CINEREA 



Leaf 



12 =13 per cent 



M 

T 92 M (79-112) 

UE... 
p 

Sp. . . . 
LE... 
OW. . . 



X 

148 M (i 19-166) 



21 



21 



44 =48 



14 = 

thin 



16 



13 

39 
82 

14 



9 per cent 



26 

55 
10 



3-7 



N. 
D. 

W. 
F.. 
L.. 

R. 
C. 

S.. 



• • 



-X".— More pubescent; upper epidermal 



Stem 



M 



X 



18 



25 



64 M (85) 55 M (79) 



7-3 
4 

95 

1-6 (av. 3) 



3-8 
3-2 

9 
i-3 



60 

73 



57 
77 



X. — Like the majority in the greater 



cells smaller in depth, same in surface number of vessels of smaller area (but the 

extent; first layer of palisade deeper and final product greater), the smaller lumen 

a second layer developed ; vessels in mid- of the fibers, and the heavier scle- 

nb of the same size but more numerous; renchyma; differing in thinner walls and 



more sclerenchyma and collenchym 
crystals abundant.— Figs. 8 and 9. 



cork, and occasionally large number of 
rings produced in M 




8 




9 

igs. 8, g.—Juglans cinerea: sections of leaves; fig. 8, mesophytic form; fig. 9, 



28o 



BOTANICAL GAZETTE 



[OCTOBER 



T... 
UE. 
P... 
Sp. . 
LE. 
OW. 
Cu 



M 

148 M (137-168) 



Leaf 



LIRIODENDRON 



X 



Stem 



IS 

37 
80 

16 



10 per cent 

25 

54 
11 



2IO M (190-236) 

= 8 per cent 



17 

59 
in 

22 



28 

53 
11 



M X 

N. . . 79 131 

D. . . 34 n (48) 32 ft (41) 
W... 3.1 



3-3 



5-6 



F. . . . 3.8 
L. . . . 10. 7 
R . . . 1-3 

s 



3.2 
4.6 

8.5 
2-5 



50 



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 coUenchyma. In both, lower epi- 
dermis heavy . — Figs. 10 and 11. 




10 





12 



11 

Figs. 10-13. — Liriodendron tulipifera: 
sections of leaves; fig. io, mesophytic 
form; fig. 11, dune form; sections of 
stems; fig. 12, mesophytic form; fig. 13, 
dune form. 




13 



1012] 



STARR— ANATOMY OF DUNE PLANTS 



281 



T.... 
UE.. 
P.... 



Sp. . . 
LE.. 
OW.. 



OSTRYA VIRGINIANA 



Leaf 



M 



X 



78 m (66-95) 


110/x (91-125) 


10 =11 per cent 


11 =10 per cent 


3° =38 


43 =39 


32 


45 


6 


11 



!-3 



3-2 



N. 



F... 
R.. 



Stem 



M 



24 



D ... 48 M (75) 

W... 2.8 



3-3 
6.7 

3 



C. . . . 29 



X 

59 

26 m (37) 

2-5 

3-9 

5-6 

3-6 



64 



X. — Upper epidermis slightly thicker 



X. — Rings of sclerenchyma in the 



and wall thicker; little variation in the cortex wider and outer layers of the 
depth of the palisade, but the layer more pith more sclerenchyma tous; in all re- 
compact; stomata on lower surface only spects, except as to the thickness of the 
(in M occasionally on the upper). wall of the vessels, agreeing with the 

majority. 



POPULUS BALSAMIFERA 



T... 
UE. 
P... 



Sp.. . 
LE.. 
OW. . 
Cu.. 



Leaf 



M 
257 M (243-272) 

18 = 7 per cent 

96 =37 
129 

14 
4-3 



X 

212 M (195-228) 



17 



8 per cent 



94 =44 

89 
16 

5 
1.2 



N 33 
D.. 

W. . 

F... 

J J- . • 

R.. 
r 



Stem 



M 



2.9 

4.1 
7.2 

1-2 



64 



90 



X 



46 M (62) 36 M (50) 



2.6 
3-8 

6.8 




100 
90 



The only exception found to the general X.— Vessels agreeing with the majority 

fact that dune plants have thicker leaves in total area, but walls slightly thinner, 



epidermi 



walls of fibers also thinner, but lumen 



than mesophy tic. X. _„__ ., 

and palisade relatively deeper; outer wall smaller, so the amount of wood may be 

and cuticle thicker and ridged; more ves- the same; cork only starting to form in 

sels in the midrib, larger; more fibers M. 

about the stele. Both have stomata on 

both surfaces; all side walls of epidermis 

Plane except those of lower surface in M; 

double palisade. 



282 



BOTANICAL GAZETTE 



[OCTOBER 



POPULUS DELTOIDES 



Leaf 



Stem 



M 
T 193 fi (177-227) 



X 

254 M (236-295) 



M 



UE. 
P... 



13 

62 



7 per cent 



18 



7 per cent 



32 



Sp 105 =54 

LE. . .. 13 

OW... 2.3 

Cu. . . 0.8 



84 =33 
138 = 55 



14 
4 



5 



i-3 



N. . 

D.. 
W.. 
F... 

JL*» ■ . 

R.. 



46 



49 
2.6 

3-8 
6.8 



M(6 4 ) 



82 



S. . . . 94 



85 

50 A* (62) 
2.7 

3-9 
6 

i-4 

105 
98 



In both lower epidermis thickened as 



Agreeing with the majority in all 



well as upper, stomata on both surfaces points; a tendency to angled twigs and 
and side walls of epidermal cells plane, all star-shaped pith more marked in X. 
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 
layer of heavily walled cells, like a second- 
ary epidermis. Other points follow the 
general rule. — Figs. 14 and 15. 




14 



Figs. 14, 15. — Populus deltoidcs: sec- 
tions of leaves; fig. 14, mesophytic form; 
fig. 15, dune form. 




15 



19 1 2] 



STARR— ANATOMY OF DUNE PLANTS 



283 



TILIA AMERICANA 



Leaf ~ 



M 
T 90 m (90-108) 



Stem 



x 



M 



X 



UE. 
P... 



138^(135-156) 



17 

26 



19 per cent 
29 



23 



17 percent 



Sp.. . . 36 =46 
LE . . . 11 = 
OW... 3.7 



45 = 33 
52 =38 



12 



17 



12 



Cu. . . 



4 4 



I -S 



N. 
D. 

W 
F. 

L.. 

R. 

C. 



59 

38 m(53> 

2-7 
2.8 

9.6 

2-5 
58 



63 



41 
2.8 

2.4 
9.1 

i-5 

5° 



^(41) 



A".— 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 
surface wavy, upper and both in M in walls and lumina of the fibers, but 
plane; deeper palisade and tendency vessels more numerous and larger in X. 
toward second layer; midrib as in preced- 
ing X. In both hairs in the axils of the 
veins; cuticle ridged.— Figs. 16 and 17. 




16 




17 

tigs. 16 and 17. — Tilia americana: sections of leaves; fig. 16, mesophytic form; 
fi g- 17, dune form. 



284 



BOTANICAL GAZETTE 



[OCTOBER 



ULMUS AMERICANA 



Leaf 



Stem 



M 
T 102 /* (94-109) 



X 

174 ix (164-186) 



UE. 



P 



21 
29 



21 per cent 
29 



38 



22 per cent 



70 =40 



Sp 38 =37 



51 



29 



ow.. 

Cu. . 



13 = 

3-2 

thin 



13 



15 =9 
5-2 
thin 



N 

D 

W 

F. 

L. 

R. 

C. 



M 
28.5 
61 /* (104) 

3-7 
5-9 
2-9 

66 



X 



52 
61 



M ( 9 6) 



3-3 

5-7 
3-7 



5 
66 



X. — Cells of upper epidermis greater 



Vessels as in majority. X. — Walls of 



in depth; side walls plane, cuticle not vessels and of fibers very slightly thinner 

ridged (in M walls slightly wavy and than in M and lumina of fibers larger, yet 

cuticle slightly ridged on lower surface) ; masses of fibers so much more numerous 

palisade deeper sometimes double, mid- they form more wood; cork and cortical 

rib structure as in other X. In both sclerenchyma the same, 
upper surface rough, hairy (X more so); 

some epidermal cells enormous. — Figs. 
18 and 19. 




18 




19 



Figs. 18 and 19. — Ulmus americana: sections of leaves; fig. 18, mesophytic 



form: fie. 10. dune form 



1912] 



STARR— ANATOMY OF DUNE PLANTS 



285 



Shrubs 



CORNUS STOLONIFERA 



Leaf 



Stem 



M 

T 129M (120-144) 

UE... 17 =13 percent 



X 



156 m 



iS 



10 per cent 



P 



.... 34 = 26 

Sp 56 =44 

LE. . . 22 =17 
OW... 1.6 
Cu . . . thin 



48 =31 
72 =46 



21 



13 



0.8 



N. 

D. 
W. 
F.. 
L.. 
R. 
C. 



• « 



M X 

63 70 

30 m (41) 33 M (45) 



• • 



• • 



• • 



3-2 

4.7 

6.4 

1-3 



34 
S 



6.2 
2-8 



None except 112 (in 8-year 



at lenticels 



stem) 



A". — Hairs more abundant than in M, 



Epidermal cells when present papillate 



on upper surface radiating from a center and cuticle heavy; cork not formed be- 

parallel to the surface, tuberculate; on fore 5 years. In both small groups of 

lower surface simple or branched; short sclerenchyma in cortex. All points as 

hairs also found, formed as slight pro- in majority. 

longations of most of the lower epidermal 

cells, their cuticle prominently ridged; 

cells of upper epidermis smaller in all 

dimensions; side walls plane (wavy in 

Af); deposits in the form of crystals and 

oil in the cells, and wax on the outer wall; 



other points 
forms — 



as in most xerophytic 



Figs. 20 and 21. 




20 



Figs. 20, 21. — Cornus stolonifcra: 
sections of leaves; fig. 20, mesophytic 
form; fig. 21, dune form. 




21 



286 



BOTANICAL GAZETTE 



( 



[OCTOBER 



VIRGINIANA 




22 



23 



N.. 
D.. 
W.. 
F... 
L... 

R.. 

r 

V-* • • • 




Stem (figs/22 and 23) 



M 

94 

29 /* (37) 

2-3 

5-7 
5-6 

3 

56 
64 



X 



157 



24 



24 
1.6 

6.4 

4 

5 
48 

88 



M (27) 





25 % 



Figs. 22-25. — Figs- 22 and 23, Hamamelis virginiana: sections of stems; tig. 22 > 
^phytic form: fig. 21, dune form: fiers. 24 and 2K.—Prunns virginiana: sections 



meso 



IQI2] 



STARR— ANATOMY OF DUNE PLANTS 



287 



Leaf 



M 

T 119 /x (100-123) 

UE... 18 =15 per cent 



PRUNUS 



X 



Stem 



P 



198 M (187-214) 

= 8 per cent 



35 = 3° 



Sp. . . . 51 = 

LE. . . 14 = 

OW... 2.9 

Cu . . . 1.1 



43 

12 



16 
99 

66 
17 



5° 

33 

9 



N... 
D... 
W... 3.1 



M X 

76 108 

38 M(55) 35 M(45) 



6.7 
1.8 



F.. 
L.. 
R. 
C. 

S.. 



• * 



* t 



■ • 



• ♦ 



4.6 

4-7 
3 



3-5 
4.6 

4-4 
3-6 



42 
83 



61 
Si 



-X". — Hairs on lower surface (none in 



M); 



epidermi 



Only exception to the majority rule is 
the sclerenchyma, which is heavier in 



surface, of less depth, cuticle more some mesophytic forms. — Figs. 26 and 



urn 



side 



walls 



M 



midrib 



M 



below the stele is scarcely perceptible); 
oil drops, especially in epidermis and 
upper part of palisade; crystals and other 



depo 
and 25. 



■Figs. 24 



■tigs. 26-27. — Primus virginiana: sec- 



t stems 
dune f 



27. 




26 










27 



288 



BOTANICAL GAZETTE 



[OCTOBER 



PTELEA TRIFOLIATA 



Leaf 



Stem 



M 



T .. 
UE. 
P .. 
Sp. 
LE. 
OW 
Cu . 



147 M (131-156) 



14 
42 



9 per cent 



■ • 



= 29 
78 =53 



13 



9 



1 .2 



thin 



X 

185 M (177-193) 

18 =10 per cent 

56 =30 

95 =5i 
16 =9 

4.8 
i-3 



M 



X 



N.. 
D .. 
W.. 
F... 
L... 
R .. 
C .. 



51 



5i 



53 M (73) 55 A* (82) 



2 . 2 



8.4 
2-3 



3-i 
2.9 

7.2 
4-7 



50 



S3 



X. — Hairs abundant on lower surface 



(none in M): 



Agreeing with the majority, except 



dermis that collenchyma in outer cortex may 



slightly larger in surface; side walls on be no heavier in X.— Figs. 28 and 29. 
both surfaces plane and cuticle ridged 
(in M wavy and only slightly ridged); 
palisade, sponge, and midrib as in other 
X. One tree in an especially exposed 
situation, near the top of a wind sweep 
leading up from the lake, probably once 
a mesophytic pocket, had a more pro- 
nounced structure than the one figured; 
the leaf averaged 210 m in thickness, with 
an outer wall 6 . 4-8 m, heavily cutinized. 







\ 



\ 




28 



Figs. 28-29.— Ptelea trifoliata: sec- 
tions of stems; fig. 28, mesophytic form; 
fig. 29, dune form. 




29 



IQI2] 



ST A RR— ANATOMY OF DUNE PLANTS 



289 



Leaf 



T... 

UE.. 



M 

152 M (136-168) 



8 



5 per cent 



11 



Mes. .133 =88 
LE.. 

OW.. 

Cu.. 



7 



i-5 

thin 



SALIX 



NGIFOLIA 



X 

188 /t (162-212) 
12 = 6 per cent 

165 =88 
11 = 6 

3 



N 



F... 
R.. 

s... 



Stem 



M 



X 



77 



66.5 



D... 36 (1(53) 43 m(55S) 
W... 



24 
2.8 

5-3 



24 

3 

6-7 



4 
33 
33 



32 
48 



Equilateral; two rows of palisade on X. — Agreeing with the majority in the 



each side beneath a hypodermis, differ- 
entiated as a special storage region; 

stomata on both surfaces, slightly sunken. 
X. 



greater area of vessels and greater num- 
ber and size of sclerenchyma masses in 
the cortex; exceptional in the larger 



Upper palisade cells more elongated; lumen of the fibers and fewer growth 



sclerenchyma and collenchyma more 
abundant in midrib. 



rings. 



Lianas 



CELASTRUS SCANDENS 






Leaf 



M 



T 101 m (92-123) 

UE ... 14 = ! 4 pej- cen t 



P 



25 



25 



X 

164/1(138-174) 
= 14 per cent 

= 26 



Sp 49 =48 



LE. 

OW 
Cu 



• - 



J 3 
thin 



13 



22 

43 
81 

18 
4 



49 
11 



i-7 



D.. 
W.. 
F... 

R.. 
C 



-*• Coarse, often merely acute; 
prominent on the under side. M. 



Stem 



M 



N... 36 



54 
2.8 

49 

8.4 

i-3 

80 



M(78) 



X 

37 

45 • 5 M (69) 
3-6 

4-5 
7-5 

i-3 

76 



veins 



Chiefly an exception; M greater in 
area of vessels, heavier fibers and cork. 



Smooth and fine, long acuminate; veins X follows the majority in having heavier 
n ot prominent on under side; other sclerenchyma around the pith, thicker 



variations as usual. 



walls of the 
in the fibers. 



290 



BOTANICAL GAZETTE 



[OCTOBER 



PSEDERA QUINQUEFOLIA 



Leaf 



Stem 



M 



X 



M 



T.... 
UE.. 



P 



Sp. . . 
LE.. 
OW.. 
Cu. . 



no/x (99-130) 


183 M 


(164-I95) 


14 =13 per cent 


21 = 


= 11 per cent 


24 =22 


56 = 


= 3* 


59 =53 


90 = 


= 49 


x% =12 


16 = 


= 



N... 36 

D... 78 /*(i2o) 



i-5 

0.7 



3 
i-5 



W... 

F 

1 • • • • 

JLi« • • • 

R. .. 1 

C. . . . 196 
S.. . .112 



2.8 
4.6 
7.2 



X 

40.5 

61 fl (90) 

3-4 
5-9 

4-7 
1.2 

188 

62 



In both side walls of epidermal cells 



Exceptional in the smaller area of 



plane except in lower surface of M , cross-sections of vessels in X, less scle- 

cuticle ridged, hairs on the lower surface. renchyma and cork; the cork is loose 

X. — Epidermal cells larger in surface, and shreds off, so more may have been 

smaller in depth; other points as usual lost in X than in M; the other points 

except there is not greater development agree with the majority, 
of conductive tissues. — Figs. 30 and 31. 




30 




31 

Figs. 30, 31. — P seder a quinquefolia: sections of leaves; fig. 30, mesophytic form; 
fig. 31, dune form. 



igi2] 



STARR— ANATOMY OF DUNE PLANTS 



291 



RHUS TOXICODENDRON 



Leaf 



M 

T 79 /* (73-ii6) 



Stem 



UE. 
P... 



X 

140/* (123-198) 



9 =n per cent 
S =33 



12 



9 per cent 



10 



Sp 37 =46 

LE.. 
OW. 
Cu. . 



45 =32 
70 =56 



. 8 = 
1.9 
.thin 



12 



9 



2.7 

i-4 



N. 
D. 
W. 
F.. 

L.. 

R. 

C. 



M 

35-5 



X 



18.5 



85 A* (99) 69 m(88) 



2.4 
9.6 



2-4 

2.8 
7.2 



183 



3 
MS 



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. 




32 




33 

Figs. 32-33. — Rhus toxicodendron: sections of leaves; fig. 32, mesophytic form; 
%• 33, dune form. 



292 



BOTANICAL GAZETTE 



[OCTOBER 



SMILAX HISPIDA 



Leaf 



Stem 



(Quadrant used instead of octant) 



M 



X 



M 



X 



T , 106 /a (96- 


-129) 


168 m (157- 


-204) 


N.. 


. . 6 bundles; eac 


UE. . . 11 =11 


per cent 


22 =13 per cent 




with 2 large 


Mes. . 82 =77 




124 =74 






vessels and 18 


LE. . . 13 =12 




22 =13 






smaller 


OW... 1.5 




3-7 




D. 


, . of large ves- 


Cu. . ,thin 




1 






sels 105 



w.. 

F... 
OW. 



4 

3-2 

5-9 
18 



13 



107 
4 



3-6 
4-3 



22 



X. — Epidermal cells deeper and larger 
in surface extent; outer wall and cuticle 
heavier; cuticle more strongly ridged; 
side walls less wavy; more conductive 



X.— Two vessels larger, but not so 
many small ones; cortex more collen- 
chymatous; pith cells with thicker walls, 
pith packed with starch grains and 



and mechanical tissues, but walls thinner. crystals. 
The mesophyll shows the usual monocot 
variation, no differentiation into palisade 
and sponge. 



VITIS VULPINA 



Leaf 



M 

T 105 n (100-118) 

UE... 14 =13 per cent 



.... 28 

... 50 
LE. . . 13 



P 
S. 



OW 
Cu 




thin 



X 

153 M (127-164) 



13 ■ 

45 = 
81 = 

14 = 

1.8 



9 per cent 



29 

53 



9+ 



X. — Upper epidermal cells smaller in 



N.. 

D.. 
W.. 
F... 

JL*. * . 

R.. 
r 



Stem 



M 

9 

105 m(H2) 

4 

5-2 

7.2 
2-3 

236 



X 



10 
102 M (127) 



45 
48 

7- 1 
2-3 



3°7 



X.— Slightly more area in cross- 



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. 



IQI2] 



STARR— ANATOMY OF DUNE PLANTS 



293 



Herbs 



T... 

UE. 
P... 



Sp. . 
LE. 
OW. 



Leaf 



M 

22 SP (230-296) 

25 = 

54 ■ 



10 per cent 



21 



158 =62 



18 



7 



2.4 



ASCLEPIAS SYRIACA 



Stem 



9 per cent 



272 M (237-304) 
25 = 

77 = 

!5i = 
19 = 



M 



X 



N 



25 



18 



D 46 m (66) 64 ix (87) 



28 

56 

7 



W 

F. 



3-5 
2-9 



2.4 



L.. 

OW 



.... 17 

4 

Wood cyl 185 



4.6 

3-5 

IS 

6.4 
611 



pidermal 



X. — Area of cross-sections of vessels 



cells plane, of lower wavy; cuticle ridged smaller, larger cylinder of wood formed; 
on lower surface. X— Hairs on both walls of vessels and of fibers heavier, 
surfaces (only on lower in M); upper lumen of fibers smaller, so more wood; 
epidermal cells smaller in depth, larger outer wall of epidermis and hypodermal 
in surface ; palisades often deep in pro- collenchyma heavier, 
portion to sponge; where not, a secondary 
palisade partly organized; conductive 
and supporting tissues as usual; latex 
and other secretions more abundant — 
F igs. 34 and 35. 



SMILACINA STELLATA 



T 

UE.. 
M... 

LE.. 
OW.. 
Cu.. 



Leaf 



M 

X 74M (155-199) 
28 =16 per cent 
119 =68 



27 



16 



2.6 

o-7 



Stem 



X 

202 fl (182-242) 
30 =15 per cent 

144 =71 
29 = 



M 



Bundles in field ..12 
N in bundle 15 



14 



2.9 
0.7 



D. 
W 



OW 



27 m 

4-3 
7.2 



X 



12 



13 



32 M 

4-5 

6.4 



X. Epidermal cells smaller in depth, X. — Area of cross-sections of vessels 



larger in surface; hairs more abundant, 
more crystals deposited ; other variations 



greater; walls of vessels heavier, but 
outer wall thinner. 



as usual; 
the 



in both no differentiation in 



mesophyll, the general monocot 

situation; side walls of epidermal cells 
plane. 



294 



BOTANICAL GAZETTE 



[OCTOBER 





r o \ (o rP<K 


V~°v\ 


f r^ 


K 


/ 1 






^^h 






1° ^1 


D 


^\x\\ 


\ 1 

vn\°° 


%fool 


ft ° 


0| 


\° It 





\$k\A 


«■ ^H ~~ V 


V / 


I 

la i/ K(J 


** J 


o j \ Y \p\ 


£o°/x/ 


/ \ Ci/ 






6f *^~^\t> ° 


~%-*lP&^ 


(o\ 


Stfr^ 


<^& oVP 




"c^ o 


sjo\ 


7^ o t-V^ — K 




oo. — ; 




X^s ~"^-— ^ 


■^? O o ° °) 


4 *^^ 




o\ 




o) 




oj 


/O] 











34 



o o 



O o° 



X) 



o 




Figs. 34, 35. — Asclepias syriaca: sections of leaves; fig. 34, mesophytic form 
ic. dune form. 



i9"J STARR— ANATOMY OF DUNE PLANTS 



295 



Swamp forms 



Sometimes a moving 



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. 



Leaf 



PLATANUS OCCIDENTALS 



Stem 



s X s X 

T IS2 a (136-162) 199 /* (162-205) N 66 69 

UE. . . 23 =15 per cent 25 = 12 per cent D 35 p (50) 46 m (63) 

P 52 =34 63 =32 W.... 3.2 3.2 

Sp.... 62 =41 g2 = 4 6 p 5 3.2 

LE... 16 =10 19 =10 L 6.4 7 

0W — * 2.8 R.... 3 2 

C 68 6.9 

S 100 116 

Collen 56 109 

The dune form has thicker leaves than The dune form shows an increase in 

the swamp form, but the palisade and number and size of the vessels, but there 
outer wall of the epidermis are excep- is no increase in woody tissue furnished 
tlonaL by the fibers. There seems to be no 

diminution in growth as indicated by 
the growth rings, but mechanical tissue 
outside the stele and the cork have in- 
creased. 



us INCANA 



N, 
D 
W 
F. 

L. 



Stem 

5 x 



68 61 Swamp form, vessels larger than the 

29 34 others but fewer in number. Dune 

2.5 2.6 form, larger area of vessels. Thickness 

3.5 3.4 of walls about the same. 

7 8.8 



CEPHALANTHUS OCCIDENTALIS 



Leaf 
5 X 

•• • I 7S M (143-168) 163 /x (147-189) A second layer of palisade is partly 

16 = 9 per cent 17 =10 per cent organized in the swamp form and com- 

*••• 54 =31 48 =29 pletely in the dune form. The first 

p.. 91 = 5 2 84 =52 palisade is relatively shorter in the dune 

• x 4 = 8 I4 = g form, but the second is so much more 

3 3.7 compact than in the swamp form that it 

u - I -6 2 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. 



296 



BOTANICAL GAZETTE 



[OCTOBER 



SALIX GLAUCOPHYLLA 



u 



Leaf 



X 



T.... 
UE.. 
P.... 
Sp. . . 
LE.. 
OW.. 
Cu.. 



185 /x (180-208) 


231 /x 


(219-240) 


20 =10 per cent 


19 = 


■ 9 per cent 


92 =50 


120 = 


: 52 


57 = 3* 


60 = 


: 3o 


16 = 8 


19 - 


: 9 


43 


4.8 




1.6 


1.6 





s 

57 



Stem 



X 



64 



45 


47 


2-3 


2-4 


3-i 


4.8 


5 


3-2 


2-4 


4 


<6 


80 



N.. 

D.. 

W.. 

F... 

L... 

R.. 

Cork. 

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 m 

Wood cylinder 836 

Pith i 97 6 



3212 



Aerial 
380 M 

950 
1482 

2812 



The upper exposed part is not as large as the submerged part, but the wood 



cylinder is larger. 



N, 

W 
F. 
L. 



Submerged 
...62 



23 
2.3 

5-1 

IO.4 



Aerial 
44 

3-2 
5-6 
5.6 



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. 

N, 

D 

W 

F. 

L. 



Submerged 



42 
41 



3-2 

3 

7-7 



Aerial 

51 • 
43 

2.4 

3-2 

6.8 



In aerial stem more and larger vessels, walls slightly thicker, lumina of fibers 
smaller, giving more wood. 

The swamp forms on the whole show the same variations as the mesophytic 

forms. 



igi2] STARR— ANATOMY OF DUNE PLANTS 297 



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: 

Hairs more abundant 12 X (3 same) 

Surface of upper epidermal cells greater 9 X- 5 M (2 same) 

Depth of upper epidermal cells greater 5 X-i 2 M (4 same) 

Side walls of upper epidermal cells wavy 6 X-i 1 M 

Side walls of lower epidermal cells wavy 8 X-16 M 

Outer wall of epidermis heavier 18 X (2 same) 

Cuticle ridged 10 X- 6 M 

Palisade more completely organized 17 X (1 same) 

Better development of conductive elements 15 X- 2 M (1 same) 

Heavier sclerenchyma 14 X- 1 M (1 same) 

Heavier collenchyma 17 X 



tion of those of Populus balsamifera, 
than in the mesophytic. The poplar 
growing alone at the side of a road, so the exposure was greater 



form 



collected. 



most of the meso 
, also were thicker 



the 



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 



thickness 



Deep, compact palisade, well developed conductive elements, 



ma 



298 



BOTANICAL GAZETTE 



[OCTOBEB 



h-l 

w 




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 



which 



stomata on the upper surface also. 



me 



from 
In 



humus 



changing the water content and other soil relations, and xerophytic 



made enough shade and urotection for mes 



come 



in, so woods have developed. The exposure must 

be less here and the water relations better than on dunes with 

scantier 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 191 1 are frequently 
thicker than those collected in 1909 in the same habitat, so that 
the mesophytic form of 191 1 is sometimes thicker than the xero- 
phytic form of 1909, but the xerophytic form of 191 1 is correspond- 

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°j and 56.5°. In 1909 the tempera tui 



in 



the normal 



sunshine ai 
March and May 



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 



must have been due, at least in 



high 



three months, sunshine 



March. 



March and May 



The accompanying table (II) gives a comparison of mesophytic 
and dune forms as to nine characters of the stem. 



3°° 



BOTANICAL GAZETTE 



[OCTOBER 



pa 



Q 





C 

u 



w 




o 




Q 




g 

O 
c/3 



o 




w 

C/3 



«H!A 



H 



H 



H H g g H g H 



snuiiQ 



nh 



H H 



*!l!X 



tt « H H g H 



H 



xtquns 


g H « H 


H 


uup^]ira§ 


g H g | * *t 


w* 



vi\op3uo\ 



HHgHg g H g 



snqtf 



vapid 



« 



H H H H H 



uiapasj 



H g S H H H 



"BUBIUtSjTA 

snuruj 



H g H H 



H 



H 



« g « 



sapio^jap 
sftjndod 



HHHHHH ** tt K 



BJ3JTUIBS|Bq 

snjndOjj 



KgHggH HHH 



6ipuiBtnBij 



H g H g « H ««g 



snuiyBjj 



H 



ggHHHg g H « 



snaicr) 



tt H « H H H 



H H H 



spp3 



g 



H H H H 



g«s 



sru^sqg^ 



HggHgH g « g 



SBld^DSV 



g H g H « H 



H 



I3DV gHHHHg ggg 



I 




C 



• PS 



be 

« </3 



> 



<D S 
fcJD 



I 

cfl en cj O 



ed 

CJ 



CJ 
c/3 

> 






a 

CJ 

^3 


* 
1-4 

CJ 


C/i 


3 


l-l 


6 


A 


C/3 


«a 


C/3 


•3 


Ix 

CJ 


2^ 


o 


<£3 


£ 




•-*- 


*o 


o 


c 


2 


cj 


15 


s 


5: 


2 
^ 



o 

i 



.£ 

en 
be 

2 

to 

8. 




CJ 



8 

d 

1 

III 

CJ u 



CJ 



en 

CJ 



^J 



^ I— > 

35 o g 



g H H H H H g 



H « H 



TJJCqso 


H g H g H H 


H H H 


uoipuapoiiji 


H g H H H « 


H H H 


suBiSnf 


« g H H g H 


n«« 



1912] STARR— ANATOMY OF DUNE PLANTS 301 



A summary of stem characters is as follows : 

Vessels more numerous 14 X- 7 M (1 same) 

Vessels larger 9 X-n M (2 same) 

Total area larger 17 X- $M 

Walls of vessels heavier 16 X- 4 M (2 same) 

Walls of fibers heavier 14 X- 6 M (1 same) 

Lumen of fibers smaller 16 X- 2 M (2 same) 

More growth rings 10 X- 6 M (3 same) 

More sclerenchyma and collenchyma 15 X- 6 3f (1 same) 

Cork thicker 9 X- 8 3f (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 
m 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 
m the stem, in every case measured, were shorter in the xerophytic 



form. 



the 



seem more aDt than 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 



hich 



the plants live, or have lived in the past, is undoubted, but what 



mmediate 



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 deeo Dalisade. Haberlandt (16) said that 



disposition, and 



this 



302 BOTANICAL GAZETTE [October 



assimi 



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 



did 



assimilation was more 



cing that tissue. 



form 



a strong development light is 
him in this resoect. Stahl 



related palisade development to light. Eberdt (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. Heinricher (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 



limiting 
! more : 



but of course 



with the 



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. Gilg (14) found in the xerophytic 
family Restiaceae a mechanical ring of strongly thickened cells, 
which Volkens (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. Kohl (23) found that in some plants grown in 
damp air the sclerenchyma ring was entirely lost, xylem elements 






i9"] STARR— ANATOMY OF DUNE PLANTS 303 



bundles 



said, to differences in activity of transpiration. J 



mass 



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 



thickness 



summer 



Haber- 



landt (18) relates the number and size of the ducts to the transpir- 
ing leaf surface. Hartig (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. Volkens' plants may have reduced leaf surface or 
developed succulency, thus reducing transpiration, and so in a 
way correspond with Cannon's irrigated plants. 



C onclusions 

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 
being 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 
roots, 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. 

Mt. Holyoke College 
South Hadley, Mass. 



LITERATURE CITED 



i. Bonnier, G., Cultures experimentales dans les Alpes et les Pyrenees 



fig- 



2. , Recherches experimentales 

alpin. Ann. Sci. Nat. Bot. VII. 20 



figs. 20-47. 189 



3. Buscalioni, T., and Pollacci, G., L'applicazione delle pellicole di collodio 
alio studio di alcuni processi fisiologici nelle piante. Atti 1st. Bot. 
Pavia. N.S. 7:12. pi. 1. 1901. 

4. Clements, E. S., Relation of leaf structure to physical factors. Trans. 
Amer. Micr. Soc. 26:19-102. pis. 1-9. 1904. 

r»/\T\rliir»f Irtre circfomc rvf c/vmn rlpcprt nlnntS. uOT. 



Cannon, W. A.. Water 



fig 



Cherme 



Ann 



fig 



Bot. Gaz. 



7. Chrysler, M. A., Anatomical notes on certain strand plants. 
37:461-463. 1904. 

8. Cowles, H. C, The ecological relations of the vegetation of the sand dunes 
of Lake Michigan. Bot. Gaz. 27:95-117, 167-202, 28i-3 o8 > 3 6l ""39 I - 



figs 



9. Dufour, L., Influence de la lumiere sur la forme et la structure des feuilles. 
Ann. Sci. Nat. Bot. VII. 5:311-411. pis. 9-14. 1887. 

10. Eberdt, O., Ueber das Palissadenparenchym. Ber. Deutsch. Bot. 
Gesells. 6:360-374. 1888. 

11. Fitting, H., Die Wassersorgung und die osmotischen Druckverhaltnisse 

der Wustenpflanzen. Zeit. Bot. 3:209-275. 1911. 

12. Fuller, G. D., Evaporation and plant succession. Bot. Gaz. 52 : i93~ 2oS ' 
figs. 1-6. 191 2. 



1912] STARR— ANATOMY OF DUNE PLANTS 305 



13. Fuller, G. D., Soil moisture in the cottonwood dune association of Lake 
Michigan. Bot. Gaz. 53:512-514. 191 2. 

14. Gilg, E., Beitrage zur vergleichenden Anatomie der xerophilen Familie 
der Restiaceae. Bot. Jahrb. 13:541-606. pis. 7-9. 1891. 

15. Grevillius, A. Y., Morphologisch-anatomische Studien iiber die xerophile 
Phanerogamenvegetation der Insel Oland. Bot. Jahrb. 23:24-108. 
pis. 1-3. 1897. 

16. Haberlandt, G., Vergleichende Anatomie des assimilatorischen Gewebe- 
systems der Pflanzen. Jahrb. Wiss. Bot. 13:74-188. pis. 3-8. 1881. 

J 7» , Physiologische Pflanzenanatomie. Leipzig. Ed. by W. Engel- 

mann, 2d edition, p. 171. 1896. 
18. , Ibid. p. 279. 

19- Hartig, R., Ueber Dickenwachsthum und Jahresringbildung. Bot. Zeit. 
50:193-195. 1892. 

20. Heinricher, E., Ueber isolateralen Blattbau mit besonderer Beriick- 
sichtigung der europaischen, speciell der deutschen Flora. Jahrb. Wiss. 
Bot. 15:502-567. pis. 27-31. 1884. 

21. Jost, L., Ueber Dickenwachsthum und Jahresringbildung. Bot. Zeit. 

49:485-495, 501-510, 525-530, 541-547, 557-563, 573-579, 589-595, 605- 
611, 625-630. pis. 6, 7. 1891. 

22. Kearney, T. H., The plant-covering of Ocracoke Island. Contrib. U.S. 
Nat. Herb. 5:261-319. pis. 65. figs. 33-50. 1900. 

23. Kohl, F. G., Die Transpiration der Pflanzen und 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 auf die Gestalt und Orientirung 
der Zellen des Assimilationsgewebes. Bot. Centralbl. 11:400-406, 438- 
445- PL 5. 1882. 

26. Stahl, E., Ueber den Einfluss der Lichtintensitat auf Struktur und Anord- 
nung des Assimilationsparenchyms. Bot. Zeit. 38:868-874. 1880. 

27. Vesque, J. ? and Viet, Ch., De Tinfluence du milieu sur la structure 
anatomique des vegetaux. Ann. Sci. Nat. Bot. VI. 12: 167-176. 1881. 

28. Volkexs, G., Die Flora der agyptisch-arabischen Wiiste auf Grundlage 
anatomisch-physiologischerForschungen. pp. 156. pis. 18. Berlin. 1887. 

29. Wagner, A., Zur Kenntnis des Blattbaues der Alpenpflanzen und dessen 

biologischer Bedeutung. Sitzber. Wiener Akad. 101:487-548. pis. 12. 
1892. 



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 Karsch (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. Chodat (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 Strasburger. 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 p thick 
and the older 8-10 /*. The triple stain, safranin-gentian violet- 
orange G, was most satisfactory, but iron-alum hematoxylin 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— PARXASSIA 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 



somewhat 



ment 



Megaspores. — 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 Chodat (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. Chodat'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 (10) 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 10. 

Figs. 13-15 show the different positions of the megaspores, a 
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- 
Chodat (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. 

Embryo 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 (41 p. 84) give a 
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). Chodat's (3) figs. 661-666 show this disintegration of 
nucellar tissue. He says: 

Chez beaucoup de Gamopetales et ches quelques Dialypetales la megaspore 
qui s'est developpee dans un tres petit micelle dissont le sommet de 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 



3io 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. 



more 



com 



from 



The nucellar 
Vif> Qa.f\ The 



in fig. 35. 



ntegument 



third 



• • 



division. 



almost 



1912] PACE— PARNASSIA 



3" 



mass 



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 
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 (i) has shown it in Aster novae- 
angliae. Eichinger (6) says: 

Bei unserer Parnassia kann man fuglich 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 



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 (pi. 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 disappeared from this region. 

A similar filiform apparatus and notch are shown by Strasburger 
(21) in Santalum. This is shown quite clearly in spite of the very 
imperfect technique of that time. In Santalum 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. 4 2 - 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. ln e 



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. Chodat (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 



ie meta 
almost 



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 t 
the homotypic division; the two spindles being 
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, 



/tes without a wall 
same anthers. The 



stages shown in figs. 55-59 come from the same anthers, all the 



same 



Fertilization. 



micro 



which is usually open (figs. 30, 42, 43), curves around the tip of the 



seems 



notch (fig. 60). In this sac the other synergid is quite dark, and 

Fertilization has already 
nuclei. In fig:. 61 the 



mass 



erm 



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 thev do in the mature sac (fig. 4.0- Several 



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. 6o, yet the tortuous course 
is quite evident. But especially clear is the 



em 



into one synergid. 



sist of a very 
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. 



VRD 



the pollen tube passing into one synergid and discharging its con- 
tents there. Juel (14) has described a similar passing of the 



i9 1 2] PACE—PARNASSIA 



315 



ifraga 



Chodat (3, p. 552) says: 

Lorsque le noyau fecondant est entre dans le sac on remarque qu'au moins 
1'une des synergids perd sa turgescence et se desorganise. 

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 



3*6 BOTANICAL GAZETTE [October 



the synergid just below the notch. This 
as unfortunately all my material was t 



em 



every 



But the pollen tubes themselves were unusually clear; they could 



micro 



entered the synergid. Chodat (3) shows the sex nuclei in various 
stages of fusion in his figs. 678-680. 

Embryo. — 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 



in shape, which 



d somewhat amoeboid 
One sac was seen with 



mbryo and two endosperm 



and the other near the antipodals, and one synergid still perfect. 
Empty pollen tubes are often very persistent in Pamassia. 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 



more cells. 



em 



embry 



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 
tig. 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. 
Chodat (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 75 and 81. 



1 9 1 2] PA CE—PA RNA SSI A 



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 
be used for each. Not much work was done with the reduction 
division; but the reduced number of chromosomes in S. sponhemica 
is about 15. Juel (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- 
fraga. 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 
5". 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. Fig. 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 
%• 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. 



em 



There are no air spaces, the whole ovule being very compact and 



much more 



The 



of a mature sac is shown in fig. 81. The synergids have a well 



filiform 



as that in Parnassia. A diagram of this entire sac is shown in fig. 
82. Two of the antipodals had disappeared. The polars have 



of the sac. 



endosperm 



Saxif 



in the examples I studied. Juel (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 



ifi 



will 



mo 



Heuchera 



mo 



(fig. 84) is shown, a 



with a laree amount of parietal tissue, and a 



mature embryo sac (fig. 86). The placentae of Heuchera 



Saxift 



Drosera rotundifolia 



This material was collected near Bonn. Rosenberg (19) ^ as 
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 undergoes subsequent cell 
division as is usual in angiosperms. 



1 9 1 2 ] p A CE—PA RNA SSI A 



319 



them 



Saxif, 



The mother cell in synapsis is shown in fig. 87. It will be seen 



if 



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. 



more 



more 



more than one cell reached the mother cell stage. The 



me 



the mother cell are shown in figs. 90 and 91. In some instances the 
megaspores are not in a row, as Rosenberg (19) has shown in his 
text iig. 27, B, which is similar to fig. 25 in Parnassia. So far as 



much material 



megaspore develops in Drosera. Not 



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 
feast as strikingly developed as in Parnassia. The embryo sac 
occupies 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 



asm 



> 



the latter lies next to the inner side of the cell. This enlargement 
°f the nucellar cells, as well as the air spaces, reduces the specific 
gravity of the seed. Diels (5) says : 

They are by their constitution capable of floating. Holzner states that 
the seeds of D. rotundijolia at a temperature of about 20° are capable of floating 
f or about a month. 

In fig. 93 the third division in the sac is shown and enough of the 
nucellus to show the differentiation in it. In one nucleus the 10 
chromosomes may be counted. 



320 BOTANICAL GAZETTE [OCTOBER 



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 the egg. 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 in 
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 ot 
several cells. Fischer (9) in Ribes aureum shows ovule development 
similar to that olSaxifraga, 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. 



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 Drude in seine grundlichen Erote- 
rung der Frage (Linnaea 39:293. 1875) auf die gewichtigen Bedenken 
practischer Natur' hingewiesen hatte, die einer tlberfuhrung von Parnassia zxi 
den Droseraceen im Wege stehen. 

Engler (8), in a note in connection with the Sarraceniaceae, 
concludes with these words : 

Die Droseraceae nahere 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. 



tfruchtung. 



parently pollination).— It is apparently similar 
nalogy to the Droseraceae, but has to Saxifi 



5. Androecium. — Parnassia possesses small simple pollen grains; all of the 
Droseraceae have tetrads. 

6. Gynaecium. — Parnassia has stalked placentae, a very striking con- 
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) savR? 



isolated 



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 frequent appearance of oval, long-petioled, fleshy leaf blades, 



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 y 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. 

i. 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 01 
cells next the epidermis enlarge very greatly, giving the nucellus 01 
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. The 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 egg- 



1912] PACE—PARNASSIA $2$ 



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 



be lost. 



family. Its princi 
primary root, the 



assimilation tissue, the stipular structures, which recall the 



many 



mous 



high 



of vegetative buds are most important. In Parnassia no such 
relation to water plants is found. If one looks for a suitable place in 



must 



with 



This family has at present so little unity 



that Parnassia makes no break in its systematic 



same Question. Hallier (1%) savs: acco 



typ 



seems to me 



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 
Saxifragaceae. 



my material, I am of the 



much more 



the Saxifrag^c^, ttll u u^t u o^^ ^ «*«** *~ *.-. — 

order with the Droseraceae. For as shown above, Drosera and 



their 



ih 



stalked 



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 



2. 



12. 



Waco, Texas 



LITERATURE CITED 



Chamberlain, C. J., The eml 
20:205-212. pis. 15, 16. 1895. 



Bot. Gaz. 



pis. 12-18. 1897. 



history of Salix. Bot. Gaz. 23:147-179 



3. Chodat, R., Principes des botanique. 1907. 

4. Coulter and Chamberlain, Morphology of angiosperms. 1903. 

5. Diels, L., Droseraceae in Das Pflanzenreich von A. Engler. 1906. 



Eichinger, A., Bei 
Gattung Parnassia. 



fig 



7* , Vergleichende Entwicklungsgeschichte von Adoxa und Chryso- 

plenium. Bay. Bot. Gesells. 1-27. pis. 1-3. 1907. 
8. Engler, A., und Prantl, K., Die natiirlichen Pflanzenfamilien. Leipzig. 

1887. 
9- Fischer, A., Zur Kenntnis der Embryosackentwicklung einiger Angio- 

spermen. Jen. Zeitsch. Naturw. 14:1-44. pis. 1-4. 1880. 
10. Gates, R. R., The stature and chromosomes of Oenothera gigas. Arch. 



Zellforsch. 3: 525-552. 1909. 



GUIGNARD 



J 



fig* 



Verwandschaftsverhaltnisse 



Abhandl. Naturwiss 16:1-112. 1901. 



Sympetalen 



13- , Uber Juliana, etc. Neue Beitrage zur Stamensgeschichte der 

Dicotyledonen. Bot. Centralbl. 23:81-265. 1908. 

14. Juel, H. O., Studien iiber die Entwicklungsgeschichte von Saxifraga 

granalata. Nov. Act. Reg. Soc. Sci. Upsal. 9:1-41. pis. 1-4. i9°7- 

15. Karsch, Dr., Flora der Provinz Westfalen. 1878. 

16. Nawaschin, S., Uber selbstandige Bewegungsvormogen der Spermakerne 
bei einigen Angiospermen. Oesterr. Bot. Zeitsch. 12:1-11. pi. 8. i9°9- 

17. Peters, C. A., Reproductive orzans and embrvolotrv of Drosera. 



Proc. 



Amer. Ass. Adv. Sci. 1 897-1 898. 



Drosera 



rotundifolia 



19 



wijoli 



rotundifolia 
1909. 



fig 



1912] PACE— PARNASSIA ' 325 

20. Shreve, F., The development and anatomy of Sarracenia purpurea. 

Bot. Gaz. 42:107-126. ^/5. j-5. 1906. 
31. Strasburger, E., Zu Santalum und Daphne. Ber. Deutsch. Bot. Gesells. 

3:105-113. />/. p. 1885. 

22 « , Die Angiospermen und die Gymnospermen. Jena. 1879. 

2 3- — , Chromosomenzahl. Flora 100:389-446. pi. 6. 1910. 

24. Tischler, G., tjber Embryosack-Obliteration bei Bastardpflanzen. Beih. 
Bot. Centralbl. 2:408-420. pi. 5. 1903. 

25. Webb, J. E., A morphological study of the flower and embryo of {Spiraea) 
(Astilbe). Bot. Gaz. 33:451-460. figs. 28. 1902. 

26. Von Wettstein, R. R., Handbuch der systematischen 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: e, egg; m, megaspore; &, male 
nucleus; p, pollen tube; s, synergid; /, tube nucleus. 

Parnassia palustris 

Fig. i. — Young ovule with three large hypodermal cells; two shown in the 
drawing; the third is just back of these two. 

Fig. 2. — A somewhat older ovule with four large cells in a row, evidently 
derived from a single hypodermal cell by two successive divisions. 

Fig. 3. — A different arrangement of the large group of cells, one cell in 
mitosis, showing 20 chromosomes; from the same ovary as fig. 5. 

Fig. 4. — Sporogenous cell differentiated as 
inner integument is beginning to develop. 

Fig. 5. — Synapsis and beginning of outer integument. 

Fig. 6. — Two sporogenous cells; the larger one already in synapsis. 

Fig. 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. 

Fig. 8. — After recovering from synapsis; spirem still very long. 

Fig. 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. 

Fig. 11. — The micropylar daughter cell in same stage as fig. 10; the 
chalazal daughter cell has nucleus with spindle. 

Fig. 12.— Both daughter cells in the telophase stage; in the micropylar 
cell one chromosome failed to reach the pole and so is omitted from the mega- 
spore nucleus. 



shown 



326 BOTANICAL GAZETTE [October 



Fig. 13. — Four megaspores, apparently all increased in size but the first 
disintegrating, and the second and fourth larger than the third. 

Fig. 14. — A different arrangement of the four megaspores, probably 
occurring more often than that shown in fig. 13. 

Fig. 15. — Approaches still more nearly the usual tetrad arrangement. 

Figs. 16-22. — The variations in the early stages of the megaspores. 

Fig. 2^. — Apparently five megaspores; one nucleus is very small and seems 
to have only one chromosome, probably resulting from an abnormal division 
like that in fig. 12. 

Fig. 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. 

Fig. 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. 

Fig. 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 open micropyle. 

Fig. 27. — Two-celled sac formed from second megaspore; the third 
megaspore also developing; the epidermal layer still further disorganized. 

Fig. 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. 

Fig. 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. 

Fig. 30. — The entire ovule with two-celled embryo sac; ovule with loose 
spongy tissue at base; nucellus entirely lacking over greater part of sac. 

Fig. 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. 

Fig. 32. — Similar to fig. 31, but the lower nucleus somewhat in advance 01 
the upper; in the lower the chromosomes are short and thick, while in the 
upper the spirem is segmenting. 

Fig. 33.— Spindles for the second mitosis in the embryo sac; this sac 
developed from the second megaspore; the third megaspore also developing. 

Fig. 34. — The four-nucleate embryo sac with the spirems more or less 
completely segmented for the third division. 

Fig. 35.— Spindles for the third division in the embryo sac; in the upper 
part of the sac one spindle is almost at right angles to the paper. 

Fig. 36.— Eight-nucleate sac soon after the third division. 



• • 



19"] PACE— PARNASSIA 327 



syner ( 



Fig. 37. — Embryo sac soon after the organization of the egg apparatus, the 
egg being just under the synergids; only the lower part of it with part of its 
nucleus can be seen; polars not yet in contact. * 

Fig. 38. — Upper end of sac, slightly older 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. 

Fig. 39. — From older sac; the synergids have unusually large vacuoles, 
both above the nuclei ; polars are in contact. 

Fig. 40. — The polar nuclei have fused; vacuoles below the nuclei in the 

synergids; the filiform apparatus well developed and forming a caplike 
structure. 

Fig. 41. — This sac was cut at right angles to the one above, showing 
the whole of the egg, but only one 
four-celled sacs. 

Fig. 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. 

Fig. 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. 

Fig. 44. — The entire egg apparatus in the micropyle, the adjacent cells of 
the integument having disappeared and the egg apparatus having a squeezed 
appearance. 

Fig. 45. — -The upper part of an ovule outlined; the egg apparatus in the 
micropyle, one synergid lying above the other. 

Fig. 46. — Egg apparatus in the micropyle, but the synergids so pressed 
together that it is not possible to differentiate them. 

Fig. 47. — A diagram of the upper part of an ovule; one synergid has the 
upper end entirely out of the ovule, its lower end overlapping slightly the 
upper part of the other synergid. 

Fig. 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. 

Fig. 49.— A few pollen mother cells; in two of these synapsis is perfect, 
in the others almost so. 

Fig. 50. — The 10 chromosomes may be counted in this pollen mother cell. 

Fig. 51. — Telophase of the first division. 

Fig. 52.— Telophase of the first division in which the 10 chromosomes are 
still distinct. 

Fig. 53. — Metaphase of the second division, one nucleus showing the 
spindle and the other being cut parallel with the nuclear plate and showing the 
!o chromosomes. 






328 BOTANICAL GAZETTE [October 



Fig. 54. — The tetrad with a few spindle fibers still present. 

Figs. 55-59. — Stages in the division of the pollen grain into vegetative 
and generative cells; in fig. 57 the 10 chromosomes are shown. 

Fig. 60. — Fertilization: the pollen tube curved around the upper part of 
the synergid, which is quite dark; apparently the sperm has already fused with 
the egg; the endosperm of this sac is two-nucleate. 

Fig. 61. — The male nuclei have already fused with the egg and the primary 
endosperm nucleus; the dark mass underneath the synergid and outlined 
through it is the other synergid and some material from the pollen tube. 

Fig. 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. 

Fig. 63. — The upper end of an embryo sac; in each synergid is a synergid 
nucleus and another smaller dense nucleus (a male nucleus with fine-grained 
cytoplasm around it) ; one synergid has a third nuclear mass, the tube nucleus. 

Fig. 64. — Mitosis in both nuclei of a two-celled embryo. 

Fig. 65. — Five-celled embryo with endosperm nucleus still undivided. 

Fig. 66. — An older embryo with traces of a synergid and showing one 
endosperm nucleus. 

Fig. 67. — Older embryo with dermatogen layer differentiated; the endo- 
sperm forms a layer about two cells in thickness all around the sac with a few 
free nuclei in the interior, especially around the lower end of the embryo. 

Fig. 68. — The basal part of older embryo, showing dermatogen, plerome, 
and periblem. 

Fig. 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. 

Fig. 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. 

■ 

Saxifraga 

Fig. 71. — 5. sponhemica: outer half of young ovule showing archesponal 
cell. 

Fig. 72. — Same: the archesporiai cell has divided. 

Fig. 73. — S. crassifolia: one mother cell. 

Fig. 74.— Same: one mother cell, but two other cells are quite large and 
stain like sporogenous cells. 

Fig. 75. — S. cordifolia: one sporogenous cell. 

Fig. 76. — S. crassifolia: mother cell with three parietal cells. 

Fig. 77. — Same: entire ovule with less magnification. 



megaspores 



sac. 



Fig. 79. — Same: some megaspores showing nucellar tissue above. 



BOTANICAL GAZETTE, LIV 



PLATE XIV 




PACE on PARXASSI A 



BOTANICAL GAZETTE, LIV 



PLATE XV 




PACE on PARNASSIA 



BOTANICAL GAZETTE, LIV 



PLATE XVI 




PACE on PARXASSIA 






BOTANICAL GAZETTE, LIV 



PLATE XVII 




96 



PACE on PARNASSIA 



1912J PACE—PARNASSIA 329 

Fig. 80. — Same: a diagram of an entire ovule with two-nucleate sac; 
very compact tissue throughout the entire ovule. 

Fig. 81. — S. cordifolia: egg apparatus. 

Fig. 82. — Diagram of the same sac, showing one antipodal and the polars 
already fused near the base of the sac. 

Fig. 83. — S. crassifolia: embryo and two endosperm nuclei. 

Heuchera brixoides 

Fig. 84. — Part of ovule showing two mother cells which are not exactly 
parallel and overlap slightly. 

Fig. 85. — Mother cell after synapsis and deep in nucellar tissue. 

Fig. 86. — Mature embryo sac; filiform apparatus and notch well developed 



in the synergids. 



Drosera rotundifolia 



Fig. 87.— Mother cell. 
Fig. 88. — Mother cell with two hypodermal cells above. 
Fig. 89. — At least two sporogenous cells, one of which has passed the 
synapsis stage. 

Fig. 90. — Megaspores developed from a mother cell like that in fig. 87; 
the fourth megaspore has begun to develop the embryo sac, the other three are 
almost completely disorganized. 

Fig. 91. — Similar megaspores, but developed from a mother cell like that 
in fig. 88. 

Fig. 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. 

Fig. 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. 



Fig. 94. 



synergids 



and a somewhat dome-shaped filiform apparatus ; the polars have already fused . 
Fig. 95. — An embryo sac with pollen tube passing around the filiform 
apparatus and apparently emptying into the synergid; probably the sex nuclei 
have already fused, but the mass is so indistinct one cannot be sure of the 
contents of the synergid region. 



Fig. 96. — One synergid shows still a trace of the nucleus and the filiform 
apparatus; 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. L A N T I S 

(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 is 
attached to the middle of the inner side of the crescent-shaped 
anther. Dehiscence takes place by means of one longitudinal 



fissure. 



in eacn anuici, 



one in each of the two lobes. With resDect to the number of 



Botanical Gazette, vol. 54] 



[33° 



J 9i2] LANTIS— ABUTILON THEOPHRASTI 331 

microsporangia in an anther, Abutilon resembles Althaea (2, 4), 
Hamamelis (13), Elodea (12), the Asclepiadaceae, etc. 

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 
tor Gaura (14). The archesporial cells divide, as usual, by peri- 
clinal walls to form the primary parietal and primary sporogenous 
ce "s (fig- 3). 

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 
reported to develop directly from the primary sporogenous cell. 

As may be seen from fig. 4, there are usually two parietal layers 
m 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 Comuti (10), Silphium (9), 
and other forms; and the same account is evidently true for 
Althaea, as may be judged from Sachs'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 



(13), IP 



the time the mother cells are dividing or a little 
iclei of some of the tapetal cells divide without the 
cell walls, and tapetal cells with one, two, or three 
nd, being much like those described for Hamamelis 
V purpurea (19), and Ulmus (15) in this respect. 




1 




3 





7 



8 





9 



10 





II 



12 



4 




Figs, i 12.— Fig. 1, cross-section of the anther showing archesporium; fig- 



- -o- -) <-i"ar>-Bc*,i.niii w me aniner snowing arcnesponum, "g- -> 
primary sporogenous and primary parietal cells in longitudinal section; fig. 3, pnm ar >" 
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; 
11 ' ngltudinal section of spore mother cells; fig. 7, first division of spore mother 
cell; fig. 8, two-celled stage of spore mother cell; fig. g, second division of spore 

mother cell; fig. 10, tetrad, early stage; fig. n, later stage of tetrad; fig. 12, mature 
pollen gram . 



x 9«] LANTIS—ABUTILON THEOPHRASTI 



333 



or less elongated (fig. 5) . 



more 



mother cell is a much 



reduction division follows very closely after the first, no walls 

(figs. 8 



formed 



and 9), a condition characteristic of the dicotyledons. The 



being observed. 



arrangement 



Special study was not made of the composition 
of the developing microspores, but evidently it is sir 
microspore walls of Althaea (6), Malm (5), and Ip 
Since the tapetum reached its highest development 
formation of the tetrad, the mother cells do not becc 



remain 



While 



formed, the tapetum 
isappear until the dc 



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 mahirv* 7™!!^ ~..„;~ 



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. 



mother 



ree 



layers, the inner being a well developed tapetum, are fully formed, 
after which the characteristic heterotypic and homotypic divisions 
take place rapidly. 

This period oi tetrad formation is marked by a multiplication 
of nuclei in the tanetal cells. 



334 BOTANICAL GAZETTE [October 



lhe 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. Holden, the librarian. 

University or Cincinnati 



LITERATURE CITED 

Schacht, H., Die Pflanzenzelle. Berlin. 1852. pp. 58-64- ph- 6 -M s - I 4 r 

23- 

Sachs, J., Textbook of Botany. English Translation. Oxford. 1882. 

PP- 546-556. 

Strasburger, E., Uber den Bau und das Wachsthum der Zellhaute. 

1882. p. 89. 



1887. pp. 357-370. 



phology. Oxford. 



5. Strasburger, E., Uber das Wachsthum vegetabilischer Zellhaute. 
Hist. Beitrage. Jena. 1889. 

6. Mangin, L., Observations sur le developpement du pollen. Bull. Soc. 



Bot. France 36:391. 1889. 



The 



New 



M 



figs 



Bot. Gaz. 25:418-426. 



pis. 22-24. 1898. 
9. Merrell, W. B 



Bot. 



3-10 



10. Frye, T. C, Development of the pollen in some Asclepiadaceae. Bot. 



Gaz. 32:325-331. ph. 1 j. 1901. 
Johnston, J. B., An imbedding 

Micr. 6:2662-2663. IQ°3- 



Jour. Appl- 



igi2] LANTIS—ABUTILON THEOPHRASTI 335 



12. Wylie, R. B., The morphology of Elodea canadensis. Bot. Gaz. 37: 
1-22. pis. 1-4. 1904. 

13. Shoemaker, D. M., On the development of Hamamclis virginiana. Bot, 
Gaz. 39:248-266. pis. 6, 7. 1905. 

14. Beer, R., On the development of the pollen grain and anther of some 
Onagraceae. Beih. Bot. Centralbl. 19:286-313. pis. 3-5. 1905. 

15. Shattuck, C. H., A morphological study of litmus americana. Bot. 
Gaz. 40:209-223. pis. 7-g. 1905. 

16. Guyer, M. F., Animal micrology. Chicago. 1906. p. 44. 

17. Gates, R. R., Pollen development in hybrids of Oenothera lataXO. 
Lamarckiana and its relation to mutation. Bot. Gaz. 43:81-116. pis. 



2-4. 1907. 



Chamberlain, Morphology of angiosperms. New York 



1909. 



19- Beer, R., Studies in spore development. Ann. Botany 25:199-215 
pis. 1 j. 191 1. 



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. 1 

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. 2 Half a pound of Bertkolletta 
nuts, after the shells have been removed, are ground into a pulp. The 
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 



* Pfeffer, W., Jahrb. Wiss. Bot. 8: 429. 1872. 
'Osborne, T. B., Amer. Chem. Jour. 14:622. 1892 



am 



[336 



igi2] 



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. i, 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. i, h), as 
happens also in some kinds of 
natural grains. 










a 



b 



c 



d 







e 




g 



h 



Fig. i. — Artificial aleurone grains: a, 



The envelope varies in thick- 
ness independently of the size of 
the crystal. 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. protein crystal surrounded by an amor- 
Occasionally the outermost layer phous protein envelope in which is in- 

of the envelope differs from the dudedadropof oil which in size and posi- 

rpcf u • tlon resembles a globoid; b, similar body 

rest in being more opaque and without a n oil drop; c-A, various forms of 

Slightly granular (fig. i, g), when it crystals resembling those which occur in 
takes the form of a narrow but dis- natural aleurone grains; g, the amor- 
tinct membrane This resembles phous envelope with a differentiated outer 

the similar structure sometimes Iayer such as ° ccurs . in .? me ***" ? 
found in natural aleurone grains. 
In an experiment in which some 
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 



grains; k, grain containing three crystals, 
a condition sometimes found in natural 
grains. 



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 



i 



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, and 
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. Osterhout, in whose course in plant physiology the original 
observation was made, and with whose advice the subsequent work was 

done. W. P. ThOMPSOM Unmanl T 1 nwpr <■ h l \t 



CURRENT LITERATURE 



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 

of the biological method for separating stereoisomeric components from their 

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, Leukowitsch, Schulze and Bosshard, 

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 1 has investigated the action of 
16 fungi and 2 bacteria on leucine and glutaminic acid, from which Schulze 
and Bosshard 2 had obtained rf-leucine and /-glutaminic acid by the action 
of Penicillium. Pringsheim found that in all cases both of the components 
o* the amino-acids used were partly consumed by the organisms. In about 
one-half of the experiments both components were consumed to an equal 
degree, so that the recovered portions of the acids were optically inactive, 
ft 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. 

Herzog and his students have taken up the study of the action of fungi 
on a-/-oxyacids and d-/-amino-acids in order to gain a knowledge of the process 
involved 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 
niycelia 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 



Aminosa 



& ... . — Aminosauren 



p »be. Zeitschr. Physiol. Chem. 65:96-109. 1910. 

2 Schulze, E., und Bosshard, E., Untersuchu.^. — ._ 

seiche bei der Zersetzung der Eiweissstoffe durch Salzsaure und durch Barytwasser 
entstehen. II. Zeitschr. Physiol. Chem. 10:134-145- *&86. 

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 Herzog and Meier 3 it was found that 
the addition of lactic, tartaric, malic, mandelic, and /?-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 (/-/-tartaric 
acid were oxidized, while mesotartaric acid, which is not separable into optically 
active components, was left intact. The dextro-rotatory form was oxidized 
most rapidly. The optically active isomers of lactic acid showed scarcely 
any difference in the rate of oxidation, while /-mandelic acid was oxidized 
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, Herzog and Ripke* have studied 



* Herzog, R. O., und Meier, A., Ueber Oxydation durch Schimmelpilze. Zeitschr. 
Physiol. Chem. 57: 35-42. 1908; also Meier, A., Dissertation under the same title. 
Karlsruhe. 1909. 

ZWtf. 59:57-62. 1909. 



5 Herzog, R. O., und Ripke, O., Ueber das Verhalten einger Pilze zu organischen 
Sauren. Ibid. 73-284-289. 1911. 



x Qi2] CURRENT LITERATURE 



341 



the effects of Oidium lactis killed with acetone and ether on the lactic, succinic, 
and mandelic acids. The results obtained do not conform with those obtained 
in the foregoing experiments with P enicillium . Only lactic acid gave a greater 
carbon dioxide production than the control with distilled water. With 
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 Herzog, Ripke, and Saladin 6 
with acetone preparations of Mycoderma 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- 
mum. If that maximum has been attained by the addition of a foreign acid, 
no further 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 depressed 
in acid media, although the quantity of acid is diminished. The disappearance 
ot the acid, therefore, cannot be explained as a process of oxidation, nor is the 
process one of metabolism, since the cells were dead. In view of the compara- 
tively small quantities of acids which disappeared apparently through the action 
of the killed fungus cells, the experiments would have been more convincing 
it the authors had reported control experiments showing how much of the acids 
could be immediately recovered from the mixtures. 

In another paper by Herzog and Saladin 7 the effect of leucine on the 
carbon dioxide production of P enicillium is reported. The method of experi- 
mentation was similar to that described above in the experiments of Herzog 
and Meier, 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 Ehrlich 8 on the behavior of amino- 



Herzog, R. O., Ripke, O., und Saladin, O. Ibid. 73=290-301. 1911. 
'Herzog, R. O., und Saladin, O., Ueber das Verhaiten einiger Pilze gegen 



Aminosauren. Ibid. 73:302-307. 1911. 



X 



Ehrlich 



organge pflanzlichen Erweissstoffwechsets und ihre Bedeutung fur 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 Ehrlich and 
Jacobson 9 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 Oidium 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 2 )C0 2 H+H 2 = R • CH(OH)C0 2 H+NH 3 

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, /-tyrosin yielded rf-paraoxyphenyl-lactic acid, d-/-phenylalanin yielded 
rf-phenyHactic 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 Kotake 10 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 11 obtained the 



• Ehrlich, Felix, und Jacobson, K. A., Ueber die Umwandlung von Amino- 

sauren in Oxysauren durch Schimmelpilze. Ber. Deutsch. Chem. Gesells. 44: 888-897- 
1911. 

10 Kotake, Y., Ueber /-Oxyphenylmilchsaure und ihr Vorkommen im Harn bei 
Phosphorvergiftung. Zeitschr. Physiol. Chem. 65:397-401. 1910. 

■ Neubauer, O., und Warburg, O., Ueber eine Synthese mit Essigsaure in der 
kiinstlich durch bluteten Leber. Ibid. 70:1-9. 1910. 



i9i 2] CURRENT LITERATURE 



343 



d-acetylphenylamino-acetic acid from this substance injected into the liver 
of dogs, while Neubauer and Fromherz 12 obtained the /-acetylphenylamino- 
acetic acid as a result of yeast fermentation of the same racemic compound. 

The intermediate chemical transformations by which d-amino-acids are 
changed into alcohols with one carbon atom less in fermentation have been 

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 
epresented by the general formula 

R • CH • NH 2 -COOH+H 2 = R • CH 2 OH+CO,+NH 3 

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 2 -COOH+0 = R~CO-COOH+NH 3 



R-CO-COOH->R.CHO+CO, 



R - CHO-f 2H = R - CH 2 OH 

This interpretation is the result of experiments in which it was shown (i) that a 
keto-acid (phenylglyoxylic acid) was formed by the fermentation of phenyl- 
ammo-acetic acid, and (2) that a keto-acid (^-oxyphenylpyrotartaric acid) 
yielded the same alcohol by fermentation as the corresponding amino-acid 
(tyrosin). 1 * 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 Ehrlich 14 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. 

"Neubauer, O., und Fromherz, K., Ueber den Abbau der Aminosauren bei 
der Hefegarung. Zeitschr. Physiol. Chem. 70:326-350. 191 1. 

13 Ehrlich, Felix, Ueber die Vergarung des Tyrosins zu />-Oxyphenyl-athyl- 
alkohol (Tyrosol). Ber. Deutsch. Chem. Gesells. 44: i39~h6. 1911. 

14 -, Ueber die Bildung von Fumarsaure durch Schimmelpilze. Ber. Deutsch. 

Chem. Gesells. 44:3737-3742. i Q n. 



344 BOTANICAL GAZETTE [October 



With glycerin, alcohol, or peptone as sources of carbon, no fumaric acid is 
produced. The 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 unsaturatied 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 
Ohta, 15 who studied the decomposition of the fat of horse liver caused by five 
forms of fungi obtained by exposing culture plates in the laboratory. The 
forms were Cladosporium herbarum, Penicillium glaucum, Aspergillus glaucus, 
A. nidulans, and Actinomucor repens. All of these caused the disappearance 
of fat from the ground sterilized liver tissue. Actinomucor was the most 
active, causing the disappearance of over 60 per cent of the fat in three 
weeks. Of the others, Aspergillus used 17-20 per cent, Cladosporium 14 per 
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, 16 who experimented with the following forms: Absidia 
glauca, Circinella umbellata, Mucor mucedo, Phycomyces nitens, Rhizopus 
nigricans, Sporodinia grandis, Morteirella candelabrum, Aspergillus flavus, 
Citromyces glaber, Penicillium luteum, Sterigmatocystis nigra, and Sporotrichum 
bombyceum. 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. 

Reichel, studying the effects of acetic acid and its salts on a form 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 attributed 
to the hydrogen ion. At the same time, the salts of acetic acid, which are highly 
dissociated, are not poisonous, hence the acetate ion is not poisonous. The 
toxicity of acetic acid, therefore, must be attributed to the molecule as a whole. 



immelpilze 



nf 



bst 



dem Verhalten des Organfettes gegen Faulniss. Biochem. Zeitschr. 31: i77^ x 94- I 9 11 - 

16 Roussy, A., Sur la vie des Champignons dans les acides gras. Compt. Rend. 
153:884-886. 191 1. 



!9i2] CURRENT LITERATURE 345 






The same conclusion reached by Clark 1 ? by similar experimentation and 
reasoning many years ago seems to have escaped his notice. 

Reichel 18 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 
fungus 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. 19 

Borkorky 20 reports a number of miscellaneous experiments and observa- 
tions indicating that methyl alcohol can be used as a source of carbon by some 
tungi and bacteria. A yeast not capable of fermenting cane sugar or glucose 
grew spontaneously on a solution of mineral nutrients to which o . i per cent 
01 methyl alcohol had been added. Inoculations from this culture were made 
in solutions containing 0.0025 per cent to 5 per cent methyl alcohol. After a 
time the flasks contained vegetations of yeast and bacteria and in some cases 
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 of dust particles. 

Saito 21 reports the formation of lactic acid by Rhizopus chinensis, thus 
confirming the observations of Eijkman and of Chrzaszcz, who reported the 
production of lactic acid by Rhizopus Rouxii. These observations had been 
doubted because other instances of the production of lactic acid by filamentous 
tungi are not known. Saito identified his acid by means of the zinc and the 
^Icium salts and by the reaction of Uffelman. 

Goupil 22 finds that Rhizopus Rouxii produces in cultures up to 4 grams 

17 Clark, J. F., On the toxic eSect of deleterious agents on the germination and 
development of certain filamentous fungi. Bot. Gaz. 28:289-327; 378-404. 1899. 

* Reichel, J., Ueber das Verhalten von Penicillium gegenliber der Essigsaure 
und lhren Salzen. Biochem. Zeitschr. 30: 152-159. 1910. 

19 Hasselbrixg, H., The carbon assimilation of Penicillium. Bot. Gaz. 45: 176- 
x 93- 1908. 

^Borkorny, Th., Beobachtungen uber Pilze, welche Methylaikohol als C-Quelle 
venvenden konnen. Centralbl. Bkt. II. 29:176-188. 1911. 

21 Saito, K., Ein Beispiel von Milchsaurebildung durch Schimmelpilze. 
Centralbl. Bakt. II. 29:289-290. 1911. 

22 Goupil, R., Recherches sur VAmvlomyces Rouxii. Compt. Rend. 153:1172- 
II 74- 1911. 



V, 



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. Osterhout (Muhlenbergia 



8:44,45- 1 



^gswellia 



of Gnaphalium (G. decurrens var. glandulosum) from Colorado. — O. Paulsen 
(Arb. Bot. Have Kb. no. 65. 303-318. 1911) under the title "Marine 
plankton from the East-Greenland Sea" records the Peridiniales found on the 
Danish Expedition to Greenland in 1 906-1908 and describes a new species of 
Peridinium {P. varicans), also a new species doubtfully referred to Apodinium. 
— W. H. Rankin (Phytopathology 2:28-31. pi. 3. 191 2) 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. Moore, and A. Gepp (Journ. Linn. Soc. Bot. 40:1-245. pis. 1-7 '• 
191 1) have published an important paper entitled "A contribution to our knowl- 
edge of the Flora of Gazaland." The paper includes a general descriptive 



1000 



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. Rolfe (Bot. Mag. /. 8417. 191 2) describes and illustrates a 
new species olStanhopea (S. peruviana) from Peru, and (Kew Bull. 131-135- 
191 2) has published several new species of orchids including 4 f rom Panama 
and South America.— E. Rosenstock (Rep. Sp. Nov. 10: 274-280. 191 2) under 
the title "Filices costaricenses" has published 11 new species of ferns. — P. A. 
Rydberg (Torreya 12:1-11. 191 2) in continuation of studies of the plants 
collected on the Peary arctic expeditions gives a list of the plants secured by 
Drs. Wolf and Goodsell; the article includes a new species of Conioselinum 
(C. pumilum Rose) from Labrador. 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 (?) Kingii Wats., 
and Dipterostemon, based on Brodiaea capitata Benth.— C. S. Sargent (Rep. 
Mo. Bot. Gard. 22:67-83. 191 1) under the heading " Crataegus in Missouri 
II" has described 14 new species.— A. K. Schindler (Rep. Sp. Nov. io:4°3> 
404. 191 2) has published a new genus (Kummerowia) based on Hedysarum 
striatum Thunb. a species common to the New and Old World.— H. Schinz 
(Vierteljahrsschrift Naturf. Gesells. Zurich 56:229-268. 1911) in an artide 



zur 



and Lopriorea. — R. Schlecter 



Centemopsis, Nelsia, Neocentema, 

, 35 2- 



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. pi. 1. 191 2) has published new species of orchids, 
2 of which are from Colombia. — F. J. Seaver (Mycologia 4:45-48. pi. 57. 191 2) 
gives an account of the genus Lamprospora and adds 2 new species. — C. P. 
Smith (Muhlenbergia 7: 136-138. 191 2) records a new variety of violet {Viola 
Beckwithii var. cachensis) from northern Utah.— O. Stapf (Hooker's Ic. IV, 
10: /. 2Q4?. 191 1) describes and illustrates a new genus (Teonongia) of the 
Moraceae from Tonkin; the same author (ibid, tt. 2949, 2Q50) 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. 
191 1) presents a synopsis of the American species of Fagonia, recognizing 
12 species, 4 of which are new to science. The same author (Smith. Misc. Coll. 
56: no. ^. 1-3. 191 2) has described 3 new species of flowering plants 
from Alberta, and (ibid. no. 34. 1-3. pi. 1) describes and illustrates a new 
species of Viorna (V. Ridgwayi) from southern Illinois.— F. Stephani (K. 
Sv. Vet. Akad. Handl. 46: no. 9. 1-92. 191 1) presents the results of an 
investigation of the Hepaticae collected on the Swedish expedition to Pata- 
gonia and Tierra del Fuego in 1 907-1909; 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. 191 1) continues 
his treatment of the Hepaticae and includes several new species from America 
belonging mainly to Frullania and Archilejeunea.—C Torrend (Broteria 
Ser. Bot. 10:29-49. 191 2) under the title of "Deuxieme contribution pour 
1 etude des champignons de Pile de Madere" describes several species new to 
science and proposes a new genus (Vermkulariopsis) of the Sphaeropsidaceae. 
W. Trelease (Rep. Mo. Bot. Gard. 22:37-65. pis. 18-72. 191 1) presents an 
illustrated account of the agaves of Lower California with a synopsis of the 
2 5 reorganized species of which 17 are new to science; and (ibid. 85-97. pis. 
73-99) gives a "Revision of the agaves of the group Applanatae," to which 
group 10 species are referred, 5 being hitherto undescribed; and (ibid. 99, 100. 
pis. 100-10 j) characterizes a new variety of Agave (A. angustifolia var. Sar~ 
gentii) based on plants in cultivation at the Missouri Botanical Garden; and 
(ibid. 101-103. pis. 104-108) records 2 new species of Yucca from Texas and 
adjacent Mexico.— W. Wangerin (Rep. Sp. Nov. 10:273. 191 2) has published 
a new species of Mastixia (M. philippinensis) from the island of Luzon, P.I. 
E- J. Welsford (Ann. Botany 26:239-242. 191 2) gives an account of an alga 
found in an aquarium associated with Azolla carol iniana which was imported 
from North Carolina. The author has given the alga the name of Trichodiscus 
elegans.—H. F. Wernham (Journ. Bot. 49:317, 318. 1911) has published a new 
genus (Pteridocalyx) of the Rubiaceae from Demerara.— Different authors 
(Kew Bull. 35-44. 191 2 ) 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. 90-107) under the title " Diagnoses 



348 BOTANICAL GAZETTE [October 



africanae XL VI" several new species are described, and the following new 
genera are proposed: Isoberlinia and Paradaniellia of the Leguminosae, and 
Klaineanthus and Hamilcoa of the Euphorbiaceae. — J. M. Greenman. 

Recent work among Filicales. — Davis 23 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 
species of Nephrodium, but are most nearly related to Woodsia and Hypo- 
derris," and fall naturally into the Woodsieae-Woodsiinae group of Polypo- 
diaceae," a group that is regarded as intermediate between Cyatheaceae and 
the Aspidieae. The conclusion is suggested that the Aspidium forms have 
come from a Gradatae ancestry, and "that Peranema and Diacalpe are relatively 
early members of a phyletic drift to the Polypodiaceae." 

Bower 2 * has used a study of Alsophila (Lophosoria) pruinata as the basis 
for a discussion of an important phyletic sequence. Lophosoria is shown to be a 
more primitive type than the true species of Alsophila and worthy of generic 
separation from that genus. The phyletic relations with Struthiopteris, Onoclea, 
Cystopteris, Acrophorus, Peranema, Diacalpe, Woodsia, and Hypoderris are 
discussed and the following " progressions " announced: (i) the frequent dichoto- 
mous branching in Gleicheniaceae becomes rarer in the higher types, and the 
creeping axis of the earlier forms becomes ascending or erect in some of 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 § Martensia of Gleichenia to the solenostele 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, and 
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 a 
smaller one. 

This series is believed by Bower to constitute a true phylum, a phylum 
quite distinct from that of the ferns with originally marginal sori. The prob- 

*i Davis, R. C, The structure and affinities of Peranema and Diacalpe. Ann. 
Botany 26:245-268. ph. 28,29. 1912. 

2 " Bower, F. O., Studies in the phytogeny of the Filicales. II. Lophosoria, and 
its relation to the Cyatheoideae and other ferns. Ann. Botany 26:269-323- P ls ' 
30-36. 1912. 



19 1 2] CURRENT LITERATURE 



349 



able phyletic sequence of families, therefore is as follows: " Gleicheniaceae, 
Cyatheaceae (with minor groups, e.g., Woodsieae, etc.), Aspidieae." 



Miss Hume 



Marsili 



folia. The xylem has long received intensive study on account of its service 
in conclusions concerning phytogeny; but there are symptoms that the phloem 
is now beginning to come into its own. The stock contrasts between the sieve 



Miss 



lining 



gent granules. 



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 

tr cryptogams are larger and thicker walled and contain refrin- 
nr " * * ' alls 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 26 has discovered in the Jurassic of Yorkshire sporangia of Coniop- 
teris 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. 



Ifol 



which justifies its removal from the form-genus and its provisional placing in a 
new genus Eboracia, related in sori and spores to Conioptcris, but very distinct 
in the form of the fertile fronds.— J. M. C. 

American cecidology.— All students of the biological sciences will 
be interested in the increased 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 27 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 
unsatisfactory 



-„ to many who are unfamiliar with the subject. However, the 
list^ will prove of very great value to the student of plant pathology and 
cecidology. In a second paper 28 Felt describes 17 new species of gall midges, 

_ 2S Hume, E. M. Margaret, The history ol the sieve tubes of PUridium aqnilinum. 
with some notes on Marsilia quadrifolia and Lygodium dichotomum. Ann. Botany 
26: 573-587. ph. 54y 55 . i 9 i 2 . 

26 Thomas, H. Hamshaw, On the spores of some Jurassic ferns. Proc. Cambridge 
Phil. Soc. 16:384-388. pl. 3 . 1911. 

37 Felt, E. P., Hosts and galls of American midges. Jour. Econ. Entomology 
4-451-475- 1911. 



2* 



•, New species of gall midges. 7^.4:476-484. 1911 



350 ' BOTANICAL GAZETTE [October 



but many of them are not true gall-makers while others produce very small and 
insignificant galls. In a third paper 19 the same author describes three new 
species of dipterous gall-makers, and in the fourth 30 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. 
Beutenmuller 31 has given us another most excellent paper on the North 
American 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 

w 

of oak. Quercus 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. lanata on 5, D. notha on 3, 5 other species 
on 2 each, and 24 species on 1 each. 

The same author 32 also describes and figures two new species of Holcaspis 
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. Smith, 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. Smith's confidence 
in this line of work is expressed as follows: "I believe we have in these par- 
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 — fl ^ — * * >1 * *- ~* + k ~ •mm«l. 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 



IQII 



29 Felt, E. P., Three new gall midges. Jour. N.Y. Entom. Soc. 19: i^ 1 ^- 



30 



, New West Indian gall midges. Entomol. News 9$lt73r^7S* J 9 12, 



their galls. Amer 



Vmerican 



32 . Two new species of Holcaspis from Mexico. Psyche 18:86, 87. i9 12 - 

33 Smith, Erwin F., On some resemblances of crown gall to human cancer. 
Science N.S. 35:161-172. 1912. 



i9i 2l 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. — Mel T. Cook. 

Inheritance in flax. — Tammes 34 has studied a number of characters 
m crosses between two varieties of the common flax {Linum usitatissimutn) 
and between these and L. crepitans and L. angustifolium. She has dealt 
quantitatively with the length of seeds, length and breadth of petals, color 
of 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 2 , 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 Ft is in each case intermediate between the 
parents and no more variable than they; in the F 2 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 3 families are grown from the extreme variants of the F 2 , a still closer 
approach to one or the other P x results, apparent identity with the parental 
type being attained in several cases. From the proportion of F 2 and F 3 
families which approached in any given characteristic the condition of the 
Pi generation, Miss Tammes estimates the number of genes probably involved 
m 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 
involved. Later generations will be needed fully to test these conclusions. 
°eo. H. Shull. j 

34 Tammes, T., Das Verhalten fluktuierend variierender Merkmale bei der Bas- 
tardierung. Recueil Trav. Bot. Neerlandais 8:201-288. ph. 3-5. 1911. 






352 4 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 upon a floristic rather than an ecological basis, 
and also points to the need of some well recognized subdivision of the association, 
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.— Geo. D. Fuller. 

The black oaks.— At the meeting of the American Philosophical 
Society (Philadelphia) on April 19, 191 2, 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 arrangement according to leaf-form, and five groups of 
species are recognized, three of the Eastern states, one of the Southwest, and 
one of the Pacific states. The eastern groups are the black oaks (black jack, 
turkey oak, Spanish oak. and nuerritmn , l «mrW ™L-c (e.r*r\et naV p-rav oak, 



oak 



willow oaks (shingle oak, willow 



Mountain oak) and 



and myrtle oak). The Southwestern 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 oaks 

than these are to one another, and appear to have originated independently 
of them. 

Nuclear phenomena in the Uredineae.— Weir* 6 has published a 
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. C. 



« Gates, Frank C, The 
southeastern Wisconsin. Illi, 

James 



9-255 



r.w i ■ C tt ' review of the general characteristics and cytologic* 

^Z e T 1 , » C U ' edineae - wit h notes on a variation in the promycelium of Coleo 
sportum Pulsatilla (Str.). New Phytol. 11:129-139. 1912. 



ol. LIV 



THE 





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 



% 



Two Species of Bowenia 



Aven Nelson 
Charles J. Chamberlain 



Briefer Articles 

A New Species of Andropogon 

Evaporation and the Stratification of Vegetation 



A. S. Hitchcock 
George D. Fuller 



Current Literature 



The University of Chicago Press 

CHICAGO, ILLINOIS 

Agent* 

THE CAMBRIDGE UNIVERSITY PRESS, London and Edinburgh 

WILLIAM WESLEY & SON, London 

TH. STAUFFER. Leipzig 
THE MARUZENKABUSHIKI-KAiSHA, Tokyo. Osaka, Kyoto 



^^^^^^^^^^^^m 



^V^P^^^^^HWV^HMI 









A 















Ghe 



Botanical 



(3a3ette 



B Aontblg Journal Embracing all Departments of JBotanical Science 

Edited by John M. Coulter, with the assistance of other members of the botanical staff of th 

University of Chicago. 

Issued November 13, J9J2 




Vol. LIV 



CONTENTS FOR NOVEMBER 19 i 2 



No. 5 



THE DEVELOPMENT OF BLASTOCLADTA STRANGULATA, X. SP. (with plates xvni- 

.\\ i. J.T.Barrett ------------- 

Til K ORCHID KM BRVO -AC (with plates xxi-xxiii). Lester JO Sharp - - - - 
GROWTH STUDIES IN FOREST TRE1 . i. FIXES RIGIDA MILL (\ ni plat xiv 

and \vj. Ilarrx P. Broun ----- 



I PORATION AND THE STRATIFICATION OT VEGETATION (\VITH ONE FIGURE). GcorgC D- 



Fuller - 



- 












CONTRIBUTIONS FROM THE ROCKY MOUNTAIN HERBARIUM. XII. A on 4c 

TWO SPECIE- OF BOWENIA. Contributions from the Hull Botanical Laboratory 162 

(with four figures). Charb J. Chamberlain --------- 

BRIEFER ARTICLES 

A N v Species of Andropogon. A. S. Hitchcock -------- 



■19 



4 



4 



CURRENT LITERATURE 

MINOR VICES - 
JTES FOR STUDEXTS 



* 4 
- 4 : 






The Botanical Gazette is published monthly. '[The subscription price is 7.00 per year; the price 
of single i pies is 75 cents, f Postage is prepaid bv the publishers on' all orders from the United States, 
Mexico, Cu 1, Porto Rico, Panama Canal Zone/ Republic of Panama, Hawaiian Islands, Philippe* 
islands, Guam, Tutuila (Samoa), S anghai. % Postage is charged extra as follows : For Canada, 35 . ccn 
on annual : rip dons tal $74$), on single copies 3 c^nts tal 78 cents); for all other countries m in 

Postal Union, 84 cents on annua bscriptions (total $7.84 n single copies, 11 cents total 80 cent 
^ Remit rices should be made p. >le to The Univer icago Press, and should b m Chl ^ a |°/ >r 

New V« ; exchange, postal or express money order, if local check is used, 10 cents must be added 
collection. 

The following agents have been appointed and are authorized to quote the prices indicated : 

For the British Empire: The Cambridge Universit Pres Fetter Pane. London, E.G., and Wiin- 
w Son, 28 Essex ■ treet, crand, London. Yearly subscription includ: postage, £1 t**\ r 

each; copies, including postage, 35. bd. each. 

For ie < ntinent of i rope: Th Stauffer. Universitatsstrasse 26, Leipzig, Germany, \earl; 
*P* Qg postage ML 33 e: h ; single copies, including postage, M. 3-6° eacb - T 1 

For Jaj n and Kon : The M irus -n-Kahushi VKaisha, 1 1 to 16 honbashi Tori chome, 10* ^ 

Japan. Yea subscription icluding postage, Yen 15.75 ei single copies, including postage, 

I ich. 

Claim for missing numbers uld be n w bin the month ing the regular n nth ot pu 

c cpeet to ply m ing 1 ers free only when they have been lc m trai 

Business correspondence mid be a i to The University of Chicago Pr< Chicag l n 

Communication for the editor s iddressed to 1 be Universit of Chica u Cbw • 

Contrib or »ted ciei an propei im th particular care, t 

I *«e* s to w the form in the pages B 



Papers 

atrationa 



I 

se the tnetrl 





I thm nted pr s are not acce ed unle 

, inwhi ica >er of in the volume 



the author is willin 



CO 



pond in nCV * 



**■* +* 



to to auth en suitable origin are supplied. 

the Tantiarv nrerrrh**r Tf\/\>r % il k« e«nt r»r» «r»«it/*afirin. It adv 



the januar numb: 190 will be sent on a dication 
the e N« rations re nv article to be rfere 

Separates, if d e< mu: be red n advance' of p ton. Twen five parates 

>e >«< . A table showing approximate c 



v 









ilia? 



1 



is printed on an or bank wl 



~i addition* 



ratt 



Entered A. 



- % 



6, at 




3m| nit the pro a c py w be (^ ■ 

at CV j^o, as second -cl as 5 matter, und Act of Congre 



**i, HI 



J 



VOLUME LIV 



NUMBER 5 



4 



THE 



Botanical Gazette 



NOVEMBER 191 2 



THE DEVELOPMENT OF BLASTOCLADIA STRANGU- 

LATA, N. SP. 1 

r 

J. T. Barrett 

(with plates xviii-xx) 

The genus Blastocladia was founded and incompletely described 
in 1876 by Reinsch (6) on the single species B. Pringsheimii, 

for twenty years remained its sole representative. In 1896 



which 



made 



am 



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 (i) considers it with the genera 
which are doubtful or to be excluded from the Saprolegniaceae, 
while Schroter (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 George F. 

1 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. Pringsheimii. 

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, in a 
few drops of sterile water. After a few hours to one day large 
numbers of zoospores will have been discharged and can easily be 



? 



I 9 I 2] BARRETT— BLASTOCLADIA 355 

spread over the plate by rocking the same or by the use of a sterile 
platinum loop. Thus distributed, the zoospores soor 



germinate 



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, Flemmingr's weak 



alcohol 



fixer 



of 



from 



paraffin. Sec 



thick and stained 



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 elsewhere, 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 
especially 



which 



than two branchlets. In this 
lets of Rhipidium americanun 



') 






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, 



m 



fusion takes place and a definite central plate results. 

Fig. 1 8, 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 Pringsheim (5) f° r the 
"cellulin granules." 

In young actively growing plants the protoplasm is much 
vacuolated, granular, and contains, distributed throughout it, 
prominent nuclei containing deeply staining bodies (figs. 28, 3 2 )- 
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 Reinsch (6) as 
independent, endogenously produced cells, which he was inclined 
to believe were the origin of the reproductive organs (see figs. i 2 > 
28, 32). Thaxter (9) observed these same bodies in B. Prmgs- 
heimii, and saw no reason for assuming that they were other than 



* 19"] 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 less compact head or group (figs. 6, 7, 12). This 
type of sympodial branching occurs in depauperate specimens of 



more 



Rhipidium 
A podachlya 



It has also been noted 



Under the best normal conditions for growth, the production 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 
nse 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 



The growth of the plant is rapid when the best external condi- 



tions are offered. Observations made relative to this 
that in one case hyphae which were just emerging f 



day 



which 



with 



material 



Development of zoosporangia 



asm 



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 

(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 their 
zoospores, drop from the plant, leaving numerous scars. This was 
noted by Thaxter (9) and also by Petersen (4) • I have never 

observed this Dhenomenrm to taVf r»larp in E straneulata. Old 



1912] BARRETT— BLAST0CLAD1 A 359 

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 1 5-30 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, pre- 
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 



1912] 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 

in a number of cases have separated. Apparently 



masses 



hich would indicate that 



masses 



formed. Harper 



plasm 
decipi 



formed 



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 



in some 



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 zoo- 
spores with the nuclei in the same or different central bodies, or 
what I shall hereafter call food masses or bodies. Fig. 34 shows 



from 



Fig. 



same 



those in fig. 34. 



In preparation for germination the zoospore comes to rest, takes 



cilium 



comm 



>nly 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 

apparently broken up into a number of deeply 
staining granules. As the germ tube elongates, the nucleus 



mass 



form 



•anying 
more and more vacuolated 



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 



in most 



Fig. 42, killed with 
weak Flemming solution, reveals that body clearly, and also the 



i9"] 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 sporangia! wall, or tips of exit tubes which 
become gelatinized and allow the emission of the zoospores to take 



place. 



Rhipidium 



The zoosporangium possesses a double wall; the outer forms a cap 



which 



lifted up by the protruding inner wall; the latter forms a cylinder 



which 



it ruptures 



them free (Thaxter 10). A similar 



Sap 



So far as I have been able to learn, the structure and behavior 



differ 



sporangium 



an outer highly refractive hyaline convex cap, with a less refractive 
area between it and the protoplasm of the sporangium. The 



more 



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 
diately dissolved in the surrounding water, and to all appearances 



imme 



begin 



the exit pore is open. 

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). _ _ 

The formation of 



b 



in 



immediately 



zoosporangium 



Rhip 



its gelatinization it was enabled to stretch out in the form of a 



thin 



sac. 



examination 



364 BOTANICAL GAZETTE [November 



tion was correct. Fig. 9 shows a section through an immature 
papilla and the adjacent wall of the ^oosporangium. 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 



composition 



.lnizin 



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 Reinsch (6) and Thaxter (9) for B. Pringsheimii, and by 
Thaxter (9) for B. ramosa. In B. Pringsheimii they are called 
resting spores by Thaxter, and are considered as doubtful oospores 
by Reinsch. They are indicative of the older condition of the 



i9"] BARRETT— BLASTOCLADI A 365 



mature 



Thaxter 



mature 



smooth, and an inner 



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 
(%• x 5)- 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 



ingr When thev are mature 



three 



middle, thick, perforated, and orange colored. The peculi 



mi 



mature resting sporangia. The pores are conical in 



with 



The greatest diameter is 



view 



0.8 \l and the least 0.3/*. Fig. 16 sh 
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. 



mature 



m 



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. 

to all observations and tests made, it is necessary that the 



germinati 



I have not found any to germinate that were not at least one month 
old. This applies to cultures 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 



;rical in form i 
assume to be 



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 fx. The smaller are found in the actively glowing 
parts where nuclear division more commonly takes place. The 
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— BLASTOCLADI A . 367 

k 

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. Humphrey (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 strangulate, nov. sp — Main 
ided at the base into a number of rhi; 



oidal 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 (50-63 X 40-5 2 /*)> 
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 PJ 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 p 
high, its main axis 40-100 fi 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. 2 

Axi primario ovato ad cylindricum, basi divisionibus rhizomatoideis 
numerosis, sursum copiose dichotome v. subdichotome ramoso; ramosis 
intervallis constrictis; pseudo-septis perforatis intra ramulorum basimformatis; 
zoosporangiis ovalibus ad sphaeroidea, 50-63X40-52 /a, papillas dehiscentes 
paucas ferentibus; zoosporis ovalibus, 12X8 /x, cilio plerumque simplici 
ornatis; sporangiis perdurantibus, rotundatis, basim versus graditim angus- 
tioribus et truncatis, 45X35^, zoosporis foventibus. 

Hab. Ad aphid in aqua, Ithaca, N.Y. 

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. 

2 During May and June 1911 this species appeared several times in water c - 
tures made from two garden soils one-fourth mile apart near Urbana, 111. As it was 
found in soil collections made at different times and parts of the gardens, it was 
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 



Rabenhorst 



1892. 

Harper 



Ann. Botany 13:467- 



525. pis. 24-26. 1899. 
3. Humphrey, J. E., The Saprolegniaceae of the United States, with notes on 
other species. Trans. Am. Phil. Soc. 173:63-148. pis. 14-20. 1893. 

4- Petersen, H. E., Studier over ferskvands-phykomyceter. Saertryk af 
Bot. Tidssk. 29:345-440. figs. 27. 1909. 

5- Pringsheim, N., Ueber Cellulinkorner, eine Modifikation der cellulosen 
Kornerform. Ber. Deutsch. Bot. Gesells. 1:288-308. pi. 7. 1883. 

o. Reinsch, P. F., Beobachtungen iiber einige neue Saprolegnieae, etc. 



Jahrb. Wiss 



Thaxter 



J., Engler und Prantl 



2. Gonapodya Fischer and 



Myrioblepharis, nov. gen. Bot. Gaz. 20:477-485. pi. 31. 1895. 
9* , New or peculiar aquatic fungi. 3. Blastocladia. Bot. Gaz. 

21 : 45-52. pi. 3. 1896. 

I0 * ' , New or peculiar aquatic fungi. 4. Rhipidium, Saprotnyces, and 

Araiospora, nov. gen. Bot. Gaz. 21:317-331. pis. 21-23. 1896. 



EXPLANATION OF PLATES XVIII-XX 

Fig. i. — Biciliated zoospore. 

Fig. 2. — Different stages in the germination of the zoospore. 
( Fig. 3. — Young plant with basal cell showing rhizoids and two branches 
which are beginning to branch dichotomously. 

Fig. 4.— Young plant started on potato agar and subsequently transferred 
to water where sporangial development took place. 

Fig. 5.— Plant similar to the one shown in fig. 4, with an empty sporangium 
and another almost mature below it. 

Fig. 6.— A branch with sympodial arrangement of resting sporangia. 

Fig. 7.— Resting sporangia more closely arranged on the branchlet, a more 
frequent condition in old cultures. 






370 BOTANICAL GAZETTE [November 



Fig. 8. — A mature sporangium showing zoospores differentiated and two 
papillae of dehiscence. 

Fig. 9. — A stained section of a papilla of dehiscence. 

Fig. 10. — Another section of a papilla of dehiscence, showing the proto- 



plasm and attached inner portion of the plug drawn away from the wall. 

Fig. 11. — Early stages in the development of zoosporangia. 

Fig. 12. — A mature plant, showing the rhizoid system, manner of branch- 
ing, and arrangement of reproductive bodies. 

Fig. 13.— A mature sporangium discharging its zoospores into a thin 
vesicle which soon ruptures. 

Fig. 14. — A mature zoosporangium discharging its zoospores without the 
formation of a vesicle. 

Fig. 15. — Resting sporangium, showing the relative position of the pores 
in the much thickened wall. 

Fig. 16. — An enlarged portion of the surface of a resting sporangium. 

Fig. 17. — A diagrammatic representation of a microscopic section of the 
wall of a resting sporangium. 

Fig. 18.— Different stages in the development of the pseudo-septa located 
at definite constrictions in the hyphae. 

Figs. 19-21. — Microscopic sections through such a septum as shown in 
fig. 18, a, giving the various appearances that result. 



Fig. 22. 



sporangium 



outer walls cracked open 



? 



inner 



of 



Fig. 23.— A zoospore showing the nucleus with its accompanying mass 
reserve food material, and two cilia. 

Fig. 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, 
leaving the reserve material and nucleus with the single cilium attached. 

Fig. 25. — Zoospore coming to rest preparatory to germination; contraction 
of the cilium taking place and contents becoming granular. 

Figs. 26, 27.— Early stages in germination of the zoospore: from living 
specimens. 

Fig. 28.— Section of a young zoosporangium, showing nuclei in division 
and also several large deeply staining food bodies. 



Fig. 29. 



time 
preparatory to zoospore 



Fig. 30.— Later stage than that shown in fig. 29: many nuclei more or 

imbedded in the reserve food material; lines of segmentation appearing a 

periphery. 

Fig. 31. — Section of a zoosDoraneium in which s 



place . 



Fig. 32. 



sporangium 



gmentation has taken 

■ 

and a sub-branch. 



Fig. 33 . — Section of a mature resting sporangium. 






BOTANICAL GAZETTE, LIV 



PLATE XV III 




BARRETT on BLASTOCLADIA 



BOTANICAL GAZETTE, LIV 



PLATE XIX 




BARRETT on BLASTOCLADIA 



BOTANICAL GAZETTE, LIV 



PLATE XX 






4 



' 






V 



•, ' 









* 




V 




*■■ 






# 






J 







% 






K 










% 



•* 




































' 










MB 













- 




s* 












# 



- - 







\ 



\ 



56 



57 






■i 



^ 






■ 



58 



59 



BARRETT on BL ASTOCL ADIA 



1912] BARRETT— BLASTOCLADIA 371 



Fig. 34. — Stained zoospore from a ripe zoosporangium : nuclei very 
net; iron-alum hematoxylin. 



X 



FlG - 35- — Binucleate zoospores. 
Fig. 36. — Zoospore preparing for germination: the large reserve food 
body is broken up into small granules. 

F JG - 37- — Uninucleate germinating zoospores. 

Fig. 38. — Germinating zoospore showing the large nucleus just previous 
to division. 

Fig. 39. — Binucleate stage of a germinating zoospore. 

Fig. 40.— More advanced condition of 

Fig. 41. — Zoospore killed with iodine: nucleus clearly shown, but the 



zoospore 



food body is invisible. 

Fig. 42. 



Flemming's solution: granules sur- 



rounding the nucleus and reserve food body stained black. 

Fig. 43.— Resting nucleus, showing a large deeply staining chromatin 
mass surrounded by faintly staining cytoplasm. 

Fig. 44. — Late stage in the division of a nucleus. 

Figs. 45-55. — Various stages of nuclear division. 

Fig. 56. — A photomicrograph of zoosporangia discharging zoospores, and 
resting sporangia. 

Fig. 57.— A photomicrograph of the plant from which fig. 56 was taken. 
Fig. 58. — A photomicrograph of a small entire plant. 
Fig. 59.— A photomicrograph of a young plant grown on agar, which 
shows the arrangement of zoosporangia in chains. 



THE ORCHID EMBRYO SAC 1 

Lester W. Sharp 

(with plates xxi-xxiii) 

During the spring of 1910 it was the writer's privilege to visit 
island of Jamaica as one of a party of botanists from the Johns 



j 



1 

son. In view of the number 



embry 



j 



Baltimore, mi 



several reasons prove of value. 



& 



evolutionary 



extreme 



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 is 
small for a group as large as the Orchidaceae, they are well scattere 
throughout the family, so that taken together with species pre- 
viously described they place us in a better position to draw con- 
clusions on the general tendency of the group. 

For the sake of clearness the different forms will be considere 
separately, and only two or three of them in detail. 

1 Botanical contribution from the Johns Hopkins University. No. 25. 

Botanical Gazette. voL <a] ' ' 3/ * 



i9«] 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 



four 



from one megaspore 



Epipacti 



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 micro 



form 



megaspores. Of these the inner one only remains functional, the 



mzmg 



divides 



(fig- 3)- The nuc 

the formation of a wall (fig. 4) and the resulting nuclei again divide 

5). At the next division 



form 



(fig. 6) cell plates appear on the fibers of all four spindles, but those 
formed in connection with the chalazal nuclei usually disappear, 



that the antipodals are in most case 
When the division of the megaspore 

forms 



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 



remain free m the cytoplasm 
a bv two successive divisions fr 



. 10, n). 



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 



megaspore 



from a single megaspore. An 
: is organized; the antipodal 



may or may 

meet in the vicinity 



The various stages described in the foregoing paragraph may 
distinguished from those in the development of a sac from a 
3jle megaspore by the absence of disorganized cells at the micro- 



pylar end. 



become indistingui 



from the disorganized contents of the epidermal cells of the ! 
so that it is then unsafe to use them as evidence, but there 



ling against the assumption that the fate of the embi 
same whether it has been derived from one megaspore 



from 



This 



In this Epidendrutn, as in Epipactis, two megaspores evid 
take part in the formation of the embryo sac in a few cases, 
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, 



male 



the 



erm 



fuses with the two polars (fig. 13)- The 
nucleus formed by the latter fusion undergoes no 
division, but degenerates along with the three antipodal nuclei 
(fig. 14). 



The first few divisions of the fertilized egg are transv 



f 



embryo of a varying number 



come in. and for a time 



very regul 



Fig. 1 6 represents 



verrncosum, in which the number 
very high, forming a filament of a 



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 chaiazal 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 



formation 



an embryo sac of the usual type from a single megaspore. The 
investigation of these three additional species was not carried far 



enough to 



methods 



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. 



megaspore mother cell (fig. 19) divides 
daughter cell again divides to form tw( 



The 



outer daughter cell and megaspore disorganize (fig. 20), while 



the inner megaspore 



The 



megaspore 



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 chaiazal 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 chaiazal 



376 BOTANICAL GAZETTE [November 



may 



very soon (fig. 23) or they may remain distinct through the sub- 
sequent stages (fig. 24). In fig. 23 the egg apparatus fills an 



mbry 



male 



one 



becomes 



micro 



(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 



20-24 



, , ~. ^ ^.^^ „ 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 



(6) 



ery 



micropy 



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. 



*9«] 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 
(%• 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 
m 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 megaspore 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. 
In 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> an( * m 
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 or 8- 
nucleate sac, as beside the pollen tube there are in the micropylar 
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 transverse 
(%• 55), so that in its early stages it is filamentous, as in Eptden- 
drum. Meanwhile the placental tissue develops rapidly from all 
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 as 
here reported may be due in part to the somewhat artificial con- 
ditions under which the plant grew in the greenhouse. 



i9i 2] SHARP— ORCHID EMBRYO SAC 



379 



m 

Coelogyne massangeana and Pogonia macrophylla 



forms 



from a single megaspore 



As 



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 



great numbers 



which 



numbers but in the same manner 



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 

be furnished by foreign pollen incapable of effecting fertiliza- 



tion. 



Discussion 



main 



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 



group 



megaspores 



within 



•served, 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 



the spi 
Epidendru 



Sharp 



Shepherdii, and recently for Epipactis p 



This fluctuation results in a reduction in the number of divisions 



occurring between 



m 



When 



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 {Cyprt- 
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 is 
the uniformity shown by the embryo sac throughout a group so 
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) , Habenana 
(Brown i), Epipactis (Brown and Sharp 2), Gymnadenia (Ward 
10), Orchis (Strasburger 9), and others. 

The 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 facts 
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 nuclei 
themselves. The conditions under which the ovules of orchids 
develop within the ovary are undoubtedly much the same in the 



I9i A SHARP— ORCHID EMBRYO SAC 381 

various species, while the ovules themselves are almost exactly 
alike in structure , varying only in the matter of dimension. Thu 
since the archesporial cell in the different species has the same 

general form and initiates a series of stages develonin^ under nrar- 



same 



expected. 

Whether a row of megaspores is produced or not seems, as 
already pointed out, to be largely dependent upon the position of 



spindles 



he first two divisions. But megaspore mother 
megaspore just before division are very much a 



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 palchellns (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 



i 



. The archesporial cell in all of the species examined is hypo- 



becoming 



mother 



megaspore mo 



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. 

dendrum variegatum, E. cochleatum, E. vcmicosum, 
E- globosum, Coelogyne massangeana, and Pogonia macrophylla the 
embryo sac is of the ordinary 8-nucleate type. In Bletia Shep- 



Ep 



382 BOTANICAL GAZETTE [November 



herdii 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 is 
of the usual type; one of the two male nuclei fuses with the egg 
nucleus, while the other fuses with the two polars. 



coram 



Epidendrum a filament 



many as 20 cells may be formed. In the mature seed the 
regions have not yet been marked out in the proembryo. 

9. In all of the species examined the endosperm nuclei 
organizes without dividing. 

10. The ordinary 8-nucleate embryo sac produced by a 
megaspore is the prevailing condition among orchids. The causes 



comparative 



to be 



sought largely in the conditions surrounding the developing nuclei. 

1 1 . 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 in 



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 



ery sim 



female gametophytes very 



monoco 



1 



dijoli 



Shepherdii show that in these species the stimulus necessary to 
development of ovules with embryo sacs may be furnished 
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. William 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. Box. Gaz. 48:241-250. 
figs. 12. 1909. 

2. Brown, W. H., and Sharp, L. W., The embryo sac of Epipactis. Box. 
Gaz. 52: 439-452. pi. 10. 191 1. 

3. Campbell, D. H., The embryo sac of Pandanus. Bull. Torr. Bot. Club 

36:205-220. pis. 16, 17. 1909. 

4^ Chamberlain, C. J., Contribution to the life history of Salix. Box. Gaz. 
23:147-179. pis. 12-18. 1897. 

5- Karsxen, G., tJber die Entwicklung der weiblichen Bliithen bei einigen 
Juglandaceen. Flora 90:316-333. pi. 12. 1902. 



6. Leavixx, R. G., Notes on the embryology of some New England orchids. 
Rhodora 3 : 202-205. pi. 33. 1901. 

7. Pace, Lula, Fertilization in Cypripedium. Box. Gaz. 44 : 3 53-37 4. pis. 
24-27. 1908. 

8- , The gametophytes of Calopogon. Box. Gaz. 48: 126-137. pis. 7-g. 

1909. 

<>• Sxrasburger, E., tlber Befruchtung und Zelltheilung. 1878. 
10. Ward, H. Marshall, On the embryo sac and development of Gytnnadenia 
conopsea. Quart. Jour. Micr. Sci. 20:1-18. pis. i-j, 1880. 



EXPLANATION OF PLATES XXI-XXIII 

All figures were drawn with the aid of an Abbe camera lucida, and shov 
magnifications as follows: figs, i-iq, X1200; figs. 16-18, X295; figs. 19-24 



200 



fig 



PLATE XXI 



Epidendrum variegatum Hook. 



Fig. i. — Synapsis in megaspore mother cell. 

Inner daughter cell dividing; oute 
Fig. 3. — Functioning megaspore: outer d 
disorganized. 



• • 



megaspore 



Fig. 4.— Two-nucleate embryo sac: no wall on lingering spindle fibers. 



384 BOTANICAL GAZETTE [November 



Fig. 5 

Fig. 6 
Fig. 7 
Fig. 8 
Fig. 9 



Four-nucleate embryo sac. 

■Division to form eight nuclei. 

Megaspore mother cell dividing equally; distinct wall formed. 

•Wall has disappeared; vacuole has formed. 

Unusual arrangement of nuclei and vacuoles; nuclei in this case 



have gone into resting condition. 

Fig. 10. — Division to form four nuclei; distinct cell plates formed. 

Fig. 11. — Four-nucleate embryo sac (four megaspore nuclei): walls have 
disappeared. 

Fig. 12. — Eight-nucleate embryo sac. 

Fig. 13. — Double fertilization. 

Fig. 14. — Young proembryo: endosperm nucleus and antipodals dis- 
organized. 

Fig. 15. — Proembryo. 

Epidendrum verrucosum Sw. 



Fig. 16. — Filamentous proembryo. 

Epidendrum cochleatum L. 
Figs. 17, 18. — Two stages of the proembryo. 



PLATE XXII 



Phajus grandifolius Lour. 

Fig. 19. — Synapsis in megaspore mother cell. 

Fig. 20. — Functioning megaspore: other daughter cell and megaspore 
disorganized. 

Fig. 2 1 — Micropy lar nuclei dividing; chalazal nuclei remaining undivided. 

Fig. 22. — Six-nucleate embryo sac. 

Fig. 23.— Same: egg apparatus formed; chalazal nuclei and micropylar 
polar fusing. 

Fig. 24. — Fertilization: second male nucleus associating with other free 
nuclei of the sac. 

Figs. 25, 26.— Proembryo showing micropylar cell growing out as a 
haustorium. 



Fig. 27. — Proembryo from mature seed. 



Corallorhiza maculata Raf . 



Fig. 28. 



dividing; outer 



daughter cell disorganizing. 

Fig. 29. — Four-nucleate embryo sac. 
Fig. 30. — Micropylar nuclei dividing. 



of sac. 



Fig. 31. — Six-nucleate embryo sac: micropylar polar has migrated to 



fusing. 



Fig. 32.— Fertilization has occurred; second male nucleus lying near egg. 
Fig. 33.— Young proembryo: second male and other free nuclei of the sac 



BOTANICAL GAZETTE, LIV 



PLATE XXI 







t. 




12 





4 







13 







O 



o\o 




SHARP on ORCHID EMBRYO SAC 



BOTANICAL GAZETTE, LIV 



PLATE XXII 




SHARP on ORCHID EMBRYO SAC 



BOTANICAL GAZETTE, LIV 



PLATE XXIII 









42- 




47 








43 




48 



**> 






44 



49 













50 




SHARP on ORCHID EMBRYO SAC 



IQI2] 



SHARP— ORCHID EMBRYO SAC 



385 



PLATE XXIII 

Bletia Shepherdii Hook. 

Fig. 3^. — Synapsis in megaspore mother cell. 

Fig. 35. — Inner daughter cell dividing to form two megaspores. 

Fig. 36. — Functioning megaspore: outer daughter cell and megaspore 
disorganized. 

Fig. 37. — Two-nucleate embryo sac. 

Fig. 38. — Four-nucleate embryo sac. 

Fig. 39. — Megaspore mother cell dividing equally; wall forming. 

Fig. 40. — Wall has disappeared. 

Fig. 41. — Two nuclei dividing: wall formed at first mitosis still visible 
as a remnant in this case. 

Fig. 42. — Four-nucleate embryo sac (four megaspore nuclei). 

Fig. 43. — Six-nucleate embryo sac: micropylar nuclei have divided. 

Fig. 44. — Eight-nucleate embryo sac: no separating walls. 

Fig. 45-48. — Usual fate of the 4-nucleate embryo sac; all the nuclei 
fuse. 

Figs. 49-53. — Abnormal sacs into which male nuclei have been discharged; 
all the nuclei tend to fuse; pi, pollen tube; &, male nuclei. 

Fig. 54. — Young proembryo evidently having formed in a normal sac. 
Fig. 55. — Later stage of proembryo* 



GROWTH STUDIES IN FOREST TREES 

i. PINUS RIGID A MILL 1 

Harry P. Brown 

■ 

(with plates xxrv and xxv) 

The phenomenon of tree growth has long been a subject of 
investigation. Sachs, Hugo de Vries, Nordlinger, Mer, the 
Hartigs, Wieler, BtisGEN, von Mohl, 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 

_ * 



stimulus in trees. Investiga- 



tions dealing with 



in 



maze 



sufficient 



The present studies were undertaken with a twofold purpose, 
namely, to clear up disputed points regarding annual ring forma- 
tion in trees and to formulate laws of tree growth. Investigations 



es with this idea 
embodied in this 



thickening 



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 appears 

1 Contribution from the Department of Botany, Cornell University. No. u8 



Botanical Gazette, vol. 54] 



[386 



1912] 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. 2 Again, as met 
with in the Cycadales and Gnetales (Coulter 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 12 cm. 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 1.9m. 
above the ground. Experiments were carried on with six indi- 
viduals of this series, which were numbered I-VL 

The trees in the wild state had better be described separately 
since each was of different age and external factors varied with the 
individual. For the sake of clearness they were designated as 

2 Exceptions to this rule occur, resulting in the so-called "ring-barked" trees. 



) 



388 BOTANICAL GAZETTE [November 

A, B 7 and C. 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 snecimen about 2< m. hieh: in other 



maximum 



m 



The trunk 



posed of white pine. There were no branches above for 18 m. 
until the crown began. The latter was but fairly developed, being 
about what one might expect under forest conditions. At breast 

was ko cm. A conservative estimate 



measure 



m 



of the age would be ioo years. 

Tree B was a younger individual. Its height was approximately 
, 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, (b) light conditions, (c) crown development, 
(d) height, and (e) diameter. 

Tree C was about the age of those in the nursery, namely 20-25 
years, and rose to a height of 7 m. Branches were borne practically 



to the ground. 



cm 



Illumination was 



proximity 



underbrush 






Methods 



m 

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, so 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 leas 
one annual ring were removed at intervals of about 50 cm. Twelve 
cuttings were made in this manner with the aid of a sharp pocket- 
knife, care being taken not to rupture the cambium. Each cutting 
was placed in a separate vial, properly labeled with the date, num- 



19 1 2] BROWN— PINUS RIGID A 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 



5 



from 



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 (ii), 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. 



390 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 Ptnus 
sihestris. 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 



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 



same 



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 391 

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 cambiufh 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 (methyl 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, 19 10, all showed in cross-section the general outline 



com 



manifest 



sections. 



marked 



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 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. Busgen (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. Hartig (7) has observed 
that evidences of growth are manifest in young (10 years) specimens 
of Finns sihestris 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. 



means of bark measure 



inception 



How- 



his computations were made at the base of the trees, 
probably growth began aloft earlier. That growth was not evi- 
denced at the base of tree A was due, according to the researches 
of R. Hartig (7), to at least three causes, namely (a) long trunk, 
(b) 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 



m 



Place of cambial awakening 

* 

The question of origin of growth is still in dispute. T. Hartig 
(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. Hartig (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 






394 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, 1910. 

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. Hartig 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 
Hartig's, so here likewise growth in Pinus rigida appears to pre- 
sent an anomaly. That Hartig 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 pfogress 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 
growth 



investi 



ried on upon certain of the lateral branches. Cuttings were taken 
from each year's growth until the main axis was reached. Then 



cm 



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 in 
both directions. Time of awakening in the apical shoots of t e 



1912] BROWN— PINUS RIGIDA 395 



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. n 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 Finns 
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 


per 


Amount 


of 


Gain 


per 


Amount 


of 


Gain 


per 








days 




day 




days 




day 




days 




day 




May 


May 








June 






June 










13, '09 


29, 09 






■ 


3> °9 








15, 09 








I 


3 


S 


12 


2 


0.17 


S 


9 


O 


0.00 


35 


12 


30 


2.50 


2 


3 


5 


12 


2 


O.17 


20 


9 


IS 


I.63 


25+ 


12 


5 


0.42 


3 


8 


8 


12 


O 


0.00 


24 


9 


16 


1.78 


X 


12 


X 

m± 


X 


4 


12 


15 


12 


3 


0.25 


40 


9 


25 


2.78 


35 


12 


? 


? 


5 


12 


18 


12 


6 


O.50 


30 


9 


12 


*-33 


40 


12 


10 


0.83 


6 


12 


20 


12 


8 


O.67 


30 


9 


10 


1. 11 


35 


12 


5 


0.42 


7 


8 


13 


12 


5 


O.42 


40 


9 


27 


3 


40 


12 





0.00 
0.67 


8 


X 


10 


12 


X 


X 


30 


9 


20 


2.22 


38 


12 


8 


9 


8 


11 


12 


3 


0.2s 


40 


9 


29 


3.22. 


45 


12 


5 


0.42 


IO 


6 


10 


12 


4 


0.34 


21 


9 


11 


1.22 


30 


12 


9 


0.75 


ii 


a; 


X 


12 


X 


X 


25 


9 


X 


X 


42 


12 


17 


I.4 2 


12 


ii 


8 


12 


? 


X 


x 


9 


X 


X 


17 


12 


X 


X 



Looking at the average gain per day, we see that in cutting 6 the 
greatest increase occurred, while above and below the amount of 



However 



Compa 



gain varied irregularly with the differen 

gain in the apical shoot was but slight. 

May 25 with those of June 3, it is evic 

tion of the apical shoot, the average daily increase at the latter 

date was greater in everv case than in the former. In other words, 



with 



time. 



from 



diameter, with the exception of the termi 
May and the first of June than before ti 



considerably with the cutting and obeys no general law 



The 



J 



15, however, 



most interesting. There was a 



growth between June 3 and June 15, with the 



exception of the apical shoot. Here 



in 



formation 
gradual d 



j 



great as that of all the diameter growth 



There was then a very marked increase in 



the 



urease 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 appre- 



i9 1 2] BROWN— PINUS RIGID A 397 

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 Buckhout (2) found in Larix 



July 



form 



Hartig (6, 7) 



iber. R. 
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 Hartig in saying that 



with 



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 



following 



results are obtained. Cutting 2 showed 0.5 of the ring complete, 
cutting 4, 0.6, cutting 8, 0.85. R. Hartig (6) agrees with T. 
Hartig (8) that cessation of growth begins first in the crown in 
trees in open stand and proceeds graduallv downward. If such is 



anoma 



was accelerated in the apical portions after June 15. However 
some of Hartig'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 1.3m. height o . 45 complete 

At 3.5m. height o. 45 complete 

At 5.7 m. height 0.45 complete 

At 7.9m. height 0.72 complete 

At 12.3 m. height 0.57 complete 

At 14. 5 m. height o. 56 complete (3-4 year branch) 



398 BOTANICAL GAZETTE [November 



Hartig 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 15, 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 

l 

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 

~~ a. « 1 rwvi • • - - . , • _ •*.%.*** 



may arise from 



may 



may be true. The latter, he says, is but 



sometimes 



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 i and 4, the completed ring on February 21, 
1910, was about the same width. At cutting 8 it was but 0.85 the 



further 



— — .„, ^^.w^, rfiiij.^ uutuing iz anuwcu. <x sun iuiuiw ^~~ — 

to o . 70. It follows that in Pinus rigida, if there is such a decrease 



from 

same applies with even greater 
us and poorlv develooed crown. 



older 



i9i 2] BROWN— PINUS RIGID A 



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 determining 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 



this 



nitely. 



cambial 



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 



while 



as yet in the resting condition. Nor 



rmed 



an. 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. 



rings 



These 



miscalculation as to age. The phenomenon 



double ring formation has often been observed, especially in broad- 



leaved trees. Here 



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 



difficult 



most 



this 



manner correlated with inhibit 



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, 1 9 10, 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. Hartig (8) claimed that cambial awakening in the roots is 



much lal 
the time 
Whether 



He 



can decide. Suffice it to say, however, that the growth in thickness 
of roots must not be confused with growth in length. The latter 



manifest often as early as March 



season. 



Summary 



1. The histological cha 
iation from the normal 



wide 



thickening in the root is similar 



the stem, but differs (a) in less sharp demarcation between the 
annual rings, (b) in the biseriate character of tracheids, and if) m 
less density. 



i9i 2] 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 cambial 
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. 



former is almost 



lutely identical with that in the latter. 



mam 



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. 

n. No reliable deductions concerning cessation of cambial 
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, (b) 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 
Ithaca, N.Y. 



4Q2 BOTANICAL GAZETTE [November 



LITERATURE CITED 
i American trees. iqo8. 1 



Buckhout, W 
5:259. 1907. 



Quarterly 



3. Busgen, M., Bau und Leben unserer Waldbaume. 1897. p. 62 

4. Coulter, J. M., and Chamberlain, C. J., Seed plants. 1901 

5. Goff, E. S., The resumption of root growth in spring. Wis 



fig 



Hartig 



7- , Anatomie und Physiologie der Pflanzen. 1891. p. 262. 



8. Hartig, T., Bot. Zeit. 18:829. 1858. 

9. Hastings, G. T., When increase in thi 
12:585. 1900. 

■ 

10. Mer, E., Sur les causes de variatio] 
Bot. France 39:95. 1892. 

11. Penhallow. D. P.. Anatomv of t.h 



Science, N.S. 



Bull. Soc. 



Japan 



12. 



Reuss, H., Beitr. zur Wachstumsthatigkeit des Baumes nach praktischen 
Beobachtungsdaten des laufenden Starkenzuwachsganges an der Sommer- 
rinde. Forstlich. Zeitschr. 2: 145. 1893. 



13. Strasbu 

14. Wieler, 



1879. 



1m 



der Baume. Bot. Zeit. 56:262. 1898. 



XXV 



May 



Fig. i.— Cutting taken from apical shoot of tree III April 15, i9 IQ 5 
cambium in the resting condition ; X50. 

Fig. 2.— Same, but cutting taken about 1 m. from the apex; cambium in 
the resting condition ; X50. 

Fig. 3.— Same, but cutting taken about 2 m. from the apex; growth in 

evidence to the extent of one or two partly formed tracheids; X5°- 
Fig. 4. 

just beginning at A; compare with fig. 15X50. 

Fig. 5.— Same, but cutting taken 1 m. from the apex; growth slightly 
more advanced; compare with fig. 2; X50. 

Fig. 6.— Same, but cutting taken from the apex; growth in evidence to 
the amount of 3 or 4 tracheids; compare with fig. 3; X5°- 

Fig. 7.— Cutting taken from tree III April 15, 1910, about 3 m. from the 
apex; growth in evidence to the extent of one or two partly formed tracheids; 
X 50. 

Fig. 8.— Same, but cutting taken about 4 m. from the apex; growth in 
evidence to about the same extent as in fig. 7 ; X 50. 



BOTANICAL GAZETTE, LIV 



PLATE XXIV 






*+** 






*K 






^^^'^P** - "* 

•> -•*•»**« » 



"*#■ 



*** 



<**' 



*»..*•' 






I ;* 






*•*■•.*%• 



■ 5^* ■ " 



«£••. 0mm 



* ; 



•* • 



••§••> 




1 



2 





3 



4 





5 



BROWN on PINUS RIGIDA 



6 



BOTANICAL GAZETTE, LIV 



PLATE XXV 





7 



8 





9 



10 





11 



12 



BROWN on PINUS RIGID A 



IQI2] 



BROWN— PINUS RIGIDA 



403 



Fig. 9. — Same, but cutting taken about 5 m. from the apex; cambium in 
the resting condition; X50. 

Fig. 10. — Cutting from main axis of tree VI April 22, 1910, at a distance 
of 3 m. from the apex; growth in evidence to the extent of several rows of 
partially formed tracheids; X50. 

Fig. 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; X50. 

Fig. 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 191 1, largely by Mr. J. Francis 
Macbride, 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. Clark, of Boise, at present a student in 
the Idaho State University. During 191 1 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 



the sheaths 



mm 



wide 



panicle loosely open; rachis decreasingly scabrous toward the 
apex, with 3-9 nodes, the first internode 3 . 5-5 cm. long : rays 



the rachis 



cond 



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 

lemma thicker than and about equaling 



mm 



the second glume, lightly scabrous throughout, obtusely bifid: 
palet reaching to the notch in the lemma 
with the lower part inclosing 



chilla 



the keels from near the middle to the apex: fruit cylindrical 



with the divergent styles sometimes 

Botanical Gazette, vol. 54] 



[404 



igi2] NELSON— IDAHO PLANTS 405 



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; and lastly the rachilla between the flowers is smooth, white, and 
"wormlike" and never green as in the other. 

This is number 948 of Macbride's 191 i 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), 5-10 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. Purdy 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. umbellatus: "Stems 
bulb-bearing near base, not bracted in the middle"; "umbel of 2-4 flowers 
subtended by 2-4 linear bracts " ; " sepals ovate-laticeolate, 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. Woods 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. 
intermedins 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 



Wash. 108, and Blankinship, Mont 



i:4S). 



Macbride, Emmett, T 



Salix boiseana, n. sp. — A low shrub, forming clumps, 1-2 m. 
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- 




19 1 2] 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. Wolfii 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, 191 1, near Boise at an altitude of less than 3000 feet. 

Eriogonum fasciculifolium, n. sp. — The shrubby base low 
c-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 § Pseudo-umbellata is at once distinguished by its 
branched shrubby base and its very narrow leaves, though it has all of the 
characteristics of the section. 

A limited quantity only was secured by Miss June Clark at Tamarack, 
Washington County, Idaho, August 12, 191 1, 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): 






ni 



filiform stem 



long: cyme unequally 3-rayed, some of the rays again unequally 
trichotomous; the bracts minute, somewhat scarious: sepals 



408 BOTANICAL GAZETTE [November 



margined, about v-z mm 



stamens 



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 bat- 
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. 

Macbride 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, 3-6 m. 
high, sometimes growing in clumps and then lower and less tree- 
like: trunk short, usually less than 1 dm. 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- 
rulations; 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 4°9 

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: 

Tree size (30-40 feet high, with trunk sometimes as much as 20 inches in 
diameter): leaves ovate to obovate, with cuneate base, densely pubescent 
above, on the veins below, and on the petioles when young: calyx lobes decidu- 
ous, glandular serrate: stamens 20 (Sargent), 10-20 (Brixton, Robinson, 
and Fernald, et 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 

f 

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 
roots tocks, 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 2 cm. 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 glabra te tube : standard oblong, with rounded apicu- 
late apex, about 10 mm. long and 4 mm, 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. 



4ic 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. 

Macbride'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 5 mm. 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 Clark, from Tamarack, in the mountains of 
Washington County, Idaho, August 8, 191 1, 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. utahensis. On noting the char- 
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 is 
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. 



iqi2] NELSON— IDAHO PLANTS 411 



Secured by Nelson and Macbride on the steep cobblestone bluffs of the 
Snake River, at King Hill, Idaho, July 15, 191 1, 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 Macbride (no. 1023) in dry lava soil, on Reynolds Creek, in 
Owyhee County, July 3, 191 1 (full fruit; flowers not seen), and by Nelson 
and Macbride (no. 11 19), at King Hill, in loose lava cinders, July 15, 191 1. 



1 



Lathyrus Bradfieldianus, n. sp. — Glabrous, mostly less than 
m. 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 

1 

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. I9"335> i8 94> 
from which it is readily distinguished by its broad obtuse lower leaflets, its 
stipules with their remarkably expanded bases, its more numerous and larger 



crownlike 



at the summit of the folded claw. 



Macbride's no. 027, from Silver City, on brush covered hills, J 



191 1, is the type. Mr. William 



Miss 



Mr. A. D. Bradfield 



j 



ciative student of his local flora, who spent much time in the field assisting 



Mr. Macbride 



Clarkae, n. sd. — Perennial from 



sim 



cm 



old petiolar bases: new plants often arising from the nodes of the 
rootstock at intervals of 2-5 cm.: herbage glabrous: stemless, or 
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 pinnatelv arranged lobes or teeth ■ ned uncles filiform, about 



igi2] NELSON— IDAHO PLANTS 413 



stems 



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 



cm 



margin 



stiff white hairs; lower petals obovate, emarginate, 15-18 mm, 
long (including the straight spur with its abruptly bent acute 



tip): stigma 



smooth: seeds brown, 



lik 



There 



Viola. 

I have pleasure in dedicating this apparently strong species to Miss June 
Clark, 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 191 1. Her no. 84, from Clear Creek, in the Boise 
Mountains, July 4, 191 1, is the type. 

Chrysothamnus oreophilus artus, n. var. — Differing from 
the species in the stricter, narrowly racemose panicle, the filiform 
semi-cylindrical leaves, and the more glutinous involucres. 

Secured by Miss Clark, near Boise, September 1, 191 1, 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 latus, 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 Macbride's no. 1236, Ketchum, Idaho, July 20, 1911, is 
typical. Certain numbers by other collectors seem to be more or less 
intermediate. 

Erigeron filifolius Bloomed, n. comb. — E. Bloomeri Gray, 
Proc. Am. Acad. 6:540. 1865; E* fissuricola A. Nels. in Herb 



that form 



comes from 



mere 



comes to be known 
filifolius and its n 



this 



414 BOTANICAL GAZETTE [November 



makiner 



variability and range of the plant in hand, is so grave a matter 



from 



upon a single collection may well be questioned. No doubt there 



affirmative 



manifestly im 



sirable. 



amateurs 



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 



ms cannot be too stronsrlv em 



synonyms 



Ne\ 



NUTTALL 



renewed caution in the best of us and deep penitence in the worst 
of us. Those who lament (and that includes the " chief est 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. 

Douglas collected two plants in the region of the Columbia 
which were described in Hooker's Flora (2:20. 1834) as Diplo- 
pappus Jilifolius and D. linearis. The first of these 
ferred, and it became Erigeron Jilifolius (Trans. Am. Phil. Soc. 
7*328. 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. 5 : 3 28 - l8 3 6 )> 
and in spite of the fact that he speaks of the flowers as yellow, the 
chances are that this name refers to Diplo pappus linearis, at least 
in part, just as Nuttall's name does. In the Torre y 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 Nuttall's E. ochroleucum (loc. cit.), to which Hooker s 



igi2] 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 Coulter and Nelson's New Manual of Botany (p. 527), the 
opinion is expressed that E. curoifolius 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 Piper's species was based, has a characteristic 
pubescence that separates it from E. luteus and E. jilifolius 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. 

els {Joe. 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 E. 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 



New Manual 



terized 



j 



Cordylanthus (Adenostegia) bicolor, n. sp. — Pilose through- 
out, with gland-tipped, sub viscid hairs: stems mostly simple at 



rather 



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 t, or 4-flowered, subtended by 



purple or purplish 



surpassing 



lyx 



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 



with 



the middle lobe 
teeth: stamens 



rudiment 



filament just below the fertile one: filament 



iqi2] . 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, f ew-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 Nuttall, 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 
calyx leaves; 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 Nelson and Macbride on moist sagebrush slopes, at Ketchum, 
Blaine Co., July 20, 191 1, no. 1239 (type); Macbride, at Pinehurst, August 
17, 1911, 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 
thick 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 Macbride, no. 1457, Lemhi Forest, Mackay, Custer County, 
Idaho, July 31, 191 1. The only other specimen, seen by the writer, that 
approaches this species is Cusick's no. 1974, from bleak summits of Stein's 



4i8 



BOTANICAL GAZETTE 



[NOVEMBER 



Mountains, E. Oregon, distributed as P. kumilis, but which it is not. Cusick's 
specimen is larger in every way and less leafy on the stems. 



Artemisia 



Growing in small 



nearly simple virgate stems each from a lor 
stems rather slender, pale-green, slightly 



minu 



pu- 



berulent 



cm 



thinly tomentose below, the margins revolute, sim 



■4) divaricate lobes and the body 

Ions: heads 1 



cm 



pinnatifid, the few (2- 
nearly so: panicle narrow, dense, 7 
subspherical, 2-3 mm. high: involucral bra 
greenish center, nearly glabrous, the deli 
appearing as if obscurely fringed: bracts 



:arious margins 
1 or 2 to each 



3-6 



more or fewer ) , the mar 



ginal ones pistillate, the 



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. potens on the dry 
saline-gravelly clays of the plains. The name refers to the overpowering but 
wholly characteristic Artemisia odor. 



Type from Mackay, Jul 

University of Wyoming 
Laramie, Wyoming 



1. no. 1 



Macbmde 



TWO SPECIES OF BOWENIA 

CONTRIBUTIONS FROM THE HULL BOTANICAL LABORATORY 1 62 

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, which 
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. Bailey, 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 1 is so abundant in the Maryvale and 
Byfield region near Rockhampton that it forms a dense, but easily 



Eucalyptus bush. Mr 



IM^ 



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. 

1 Bowenia serrulata (AndrS) Chamberlain, n. comb. — B. spectabilis Hook. f. var. 
serrulata Andrg, 111. Hort. 26: 184. pi. 366 (1879); B - spectabilis var. serrata Bailey, 



jueensland 
caulibus 
land. 

419] 



;pha 
-Vicinity of Rockhampton, Queens- 



[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 







Fig. l.—Bowenia speclabilis at Babinda, Australia: about i m. in height 



Garden at Durban, South Africa, Mr. Wylie showed me '< 
Stangeria paradoxa with leaflets so deeply incised that t 
might almost be called bipinnate. In Stangeria the character is 



lm 



In some 

cies of Encephalartos the fluctuating variations in the margins 
eaflets have doubtless led taxonomists into pitfalls. 
In Bowenia the serrate or entire character of the margin is so 
stant that it would be worthv of sDecific rank even if it were not 



n 



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 

abundant in the bush. Many specimens of the 



most 



streams 



sometimes reaching 




Fig. 2. — Bowenia serrulata at Byfield, Australia: about 1.3 m. in height 



m.. while 



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 1.3 m. 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 



almost 



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. 



most 



species and the variety is in 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. 




Fig. 3. — Bowenia specta- 
bilis: a somewhat diagram- 
matic sketch of the stem of 
an ovulate plant; the por- , Fig. 4 —Bowenia serrulata: asome- 

tion shown is somewhat what diagrammatic sketch of the stem 

less than 1 m. in length; the of astaminateplant; the stem is about 

dotted line is the ground 23 cm. in diameter; the dotted line is 

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. 



IQI2] 



CH A MBERLA IN— BOW EN I A 



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. 



specimen 



Miguel 



Other specimens 



W 



Camache (St. Michel) 



D.C. 



— A. S. Hitchcock, Washington 



EVAPORATION AND THE STRATIFICATION OF 

VEGETATION 

(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 1 that the varying 

1 Yapp, 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] k 24 



IQI2] 



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 Dachnowski 2 and Sherff 3 from observations 
extending over comparatively brief periods, all of these observers work- 
ing in swamp or bog habitats. 



MAY 


JUNE j JULY 


AUGUST 


SEPTEMBER 


OCTOBEF 


1 




ap 








r 








— ■■-■^ fc 


i : 








. ■ - 


■ '" ' 


- — ■ 








\ 


























_ 


■ ■ 


— 




pa 


. 






















* ^H^^ • 


















■^ • _ ^™ 














v L*k 






■— \ 












■^^^^^^^ 




-— 
















^ 




















— -^"" 














































U- 


























































V 1 




















F\- 














































































L[c 


r 
















{ ^ 
















no 








































^k 






j 






















1 1^ 


'■ ' ■ 
































/ " 




























\ / 










Ji 






i H 








5 






































j ! J 






\\ 




















T»^ 1 




































^^^ 




t gf4^^^^ 


















— 


























































































1 

























Fig. i. 



Diagram showing the average daily rate of evaporation in three strata 



of the beech-maple forest association for the growing season of 191 1. 



The present records were obtained during the season extending from 
May 1 to October 31, 191 1, 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 Livingston atmometers have been described in a 



2 Dachnowski, A., Vegetation of Cranberry Island. Bot. Gaz. 52:126-149. 



1911. 



Sherff 



Bot. Gaz. 53 "4* 5-435- l 9 12 - 



426 . BOTANICAL GAZETTE [November 



previous paper.* 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 Livingston atmometer as ordinates (fig. i). The interme- 
diate graph (fig. ib) represents the mean of three stations situated upon 
the forest floor, with the atmometers 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. id) 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. id) 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 V-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 : o . 80 f or 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. Cuadlaria, Impatiens biflora, and Asplenium 
angustij olium — George D. Fuller, University of Chicago. 

< Fuller, G. D., Evaporation and plant succession. Bot. Gaz. 52: 193-208. I9»« 



CURRENT LITERATURE 



MINOR NOTICES 

Das Pflanzenreich. 1 — Part 46 is a monograph of the Menispermaceae by 
Professor Ludwig Diels. 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. Tw t o new r genera are added, 
namely Platytinospora, based on Tinospora Buekholzii Engl, of tropical Africa, 
and Sinomenium, based on Cocculus diver sifolius Miq. of Asiatic distribution. 

Part 47 continues the monographic treatment of the Euphorbiaceae by 
Professor Ferdinand Pax, including only the tribe Cluytieae. The author 
divides the tribe into four subtribes, namely Codiaeinae, Ricinodendrinae, 
Cluytiinae, 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 & 
Hoffm.) 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 Lasioideae to which are referred 18 
genera and upward of 130 species, 18 of which are here published for the first 
time. One new genus (Dracontioides) is described, based on Urospatha 
dehiscens Schott of southern Brazil. Amorphophalliis is by far 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 Perkins, 
and records the results of a continued study of this family from new material 
represented in the leading European herbaria, particularly the Berlin herbarium 



1 ENGLER, A., Das Pflanzenreich. Heft 46 (IV. 94). Menispermaceae von 
L. Diels. pp. 345. figs. 93 (917). 1910. M 17. 40. Heft 47 (IV. i47« *&)• 
Euphorbiaceae-Cluytieae, unter Mitwirkung von Kathe Hoffmann, von F. Pax. 
pp. 124. fig Sm 35 (144); (IV. 116). Cephalotaceae von J. M. Macfarlane. pp. 15. 
figs. 4 (24). 191 1. 3/7.20. Heft 48 (IV. 23C). Araceae-Lasioideae, von A. 



Engler. pp. 130.^. 44 (415). 1911. M6.60. Heft 49 (IV. 101. Nachtrage). 
Monimiaceae (Nachtrage) von J. Perkins, pp. 67. figs 
Leipzig: Wilhelm Endemann. 



15 (112). 1911. M 3.60. 



427 



N 



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, namely 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 2 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. 



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 catalogues. — Charles J. Chamberlain. 



Handbook 



Schneider 



appear, and at the completion of the first volume (1906) it was reviewed in 



this journal. 



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 



2 Lister, Arthur, and Lister, Gulielma, A monograph of the Mycetozoa, a 
descriptive catalogue of the species in the herbarium of the British Museum. 8vo. 
pp. 1-302. pis. 201. figs. 56. London: Printed by order of the Trustees of the British 
Museum. 191 2. 

3 Bot. Gaz. 43:43:214. 1907. 

« Schneider, C. K., Illustriertes Handbuch der Laubholzkunde. Zwolfte 
Lieferung. Imp. 8vo. pp. 817-1070. figs. 515-628. Jena: Gustav Fischer. 19* 1 - 
M 5. Also Register, pp. vii+138. M 5. 



19 1 2] CURRENT LITERATURE 



429 



the monocotyledons {Yucca to Agave), and also an extensive supplement 
(pp. 869-1065) to all the preceding parts. — J, M. C. 

■ 

North American flora. 5 — 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 S chaff nerella, based on Schajfnera gracilis 
Benth. from Mexico. Several transfers are made, and new species are described 
in the following genera: S chizachyrium (4), Andropogon (1), Amphilophis 
(1), Sorghastrum (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 fur 
Zellforschung. Allen 6 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 afidrocytes, 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 plate, 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. Previous 
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, 
mantle fibers, and usually a few short, freely ending ones. ■ 

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 



5 North American flora, vol. 17, part 2, pp. 99-196. New York Botanical 
Garden. September 18, 191 2. 

6 Allen, C. E., Cell structure, growth, and division in the antheridium of Poly- 
iridium jwiiperinum Willd. Archiv fur Zellforschung 8: 121-188. pis. 6-9. 191 2. 



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 
connecting fibers between the chromosome groups increase in number, pull 
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 Polytrickum, 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 is 
emphasized. 



I9i 2] 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 \V. Sharp. 

Mallow rust. — In an elaborate paper Eriksson 7 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 Eriksson's investigation, and upon which he brings 
to bear the results of a vast amount of painstaking work. 

The main contentions of Eriksson are that the fungus 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 summarized 



here. 



fungu 



— - 

in many places it was first observed on plants grown from seed obtained froni 
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 



fungu 



In 



grown 



gularly 



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 Entwickelungsgeschichte. Kungl. Svensk. Vetensk. Handl. 47: 
5-120. pis. 6. figs. 18. 1911. For summaries previously published by the author 
see Compt. Rend. 152:1776-1779. 1911, and Centralbl. Bakt. 3* : 93-^5- *9 XI - 



432 BOTANICAL GAZETTE [November 

secondary infection from sporidia are localized in groups near the points of 
infection. Neither the mvcelium nor the spores 



survive 



The teleutospores of this rust are of two kinds, and although they are 



indistinguishable 



typ 



of the second type produce slender germ tubes, whose terminal portions 
break up into several independent cells or conidia. The 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 
ceils, 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 
these infections. The protoplasm of the fungus enters into a state of sym- 
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 8 



germination 



> 



finds 



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 



found 



With 



time required for germinatio 



from 24 hours to 6 days. This observation is quite contrary to the experience 
of Dietel, 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 

8 Taubenhaus, J. J., A contribution to our knowledge of the morphology and 
life history of Puccinia Mahacearum Mont. Phytopathology 1:55-62. pis. 3- I 9 11 - 

» Dandexo, J. B., Further observations on the life history of Puccinia Mahace- 
arum. Rep. Mich. Acad. Sci. 12:91, 92. 1910. 



igi2] 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. 

Although 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. 



Germination. — 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, 10 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 pressure, nitric acid, 
and Knop's solution influence now disk seeds, now ray seeds, or both, or 
neither according to species, apparently without regularity. Age and possible 
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 differences, 
which always become much less on removal of the fruit coat. These differ- 
ences in germination do not, therefore, as Ernst, and Correns assumed, rest 
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 11 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 



10 



bei 



derselben Species. Inaug. Diss. pp. 7-129. 191 2. 



11 Shull, Chas. A., The oxygen minimum and the germination of Xanthium 



seeds. Bot. Gaz. 52:453-477. 191 1. 



12 



germination. Bot. Gaz. 42: 265- 



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 Xanthiutn, 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 Rubsaamen 1 * on the cecidia of Africa and Asia 
describes 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 1 * on the Acarus cecidia of the vine describes both 
the hypertrophies and the parasites. It is well illustrated with photographs 
of the injuries, microphotographs showing structures of the cecidia, and line 
drawings of the parasites. The subject is treated primarily from the stand- 
point of plant pathology and includes a description of one new species {Phyl- 
locontes viticolus) and an excellent bibliography. 

A paper by Paris and Trotter 1 * gives a very important chemical study 
of the well known European gall of Neuroterus baccarum and the unaffected 



saamen 



ioa-13 



V. Gallen aus Africa und Asien. Marcellia 10 

J 4 Pantanelli, E., L'Acariosi della vite. Marcellia Io;x33"iS°- I 9 11 - 

** Paris, G., and Trotter, A., Sui composti azotati nelle galle di Neuroterus 

baccarum. Marcellia 10:150-159. 1911. 



1912] . 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 Houard 16 is subdivided into five parts as follows: (i) 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 Oka europaea 
L. is caused by Bacillus oka (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 Smith 17 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 explanation 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. 
Ohno 18 has already shown how "hygro-diffusion" leads to such a molar extru- 
sion of gas in the leaf of N dumbo nucifera, and has explained the physics of 
the action. Now Ursprung 19 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 Ohno in all essential points, 
although that author has given the earlier literature a less critical considera- 
tion than is desirable. As Ursprung 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 role in these forms. 



Houard 



Smith 



Marcellia 10:160-184. 1912. 
tropical teratology. Ann. Jard. 



Bot Buitenzorg II. 9:98-116. pis. 5. 191 1. 
i8 Bot. Gaz. 51:310. 191 1. 

19 Ursprung, A., Zur Kenntnis der ( 
156. 1912. 



Flora 104:129- 



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 17 cm. 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. Ursprung 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 
plays no considerable role in the gas exchange of land plants with their narrow 
intercellular systems, and of course no part in submerged leaves. The studies 
of Ohno and Ursprung now make possible a much more lucid statement of 
gas movements and pressures in the intercellular systems of plants than was 
formerly 20 the case. — William Crocker. 



* 

Cytology of rusts.— Investigations of the cytology of Puccinia 
Falcariae by Dittschlag 21 and of Endophyllum Sempervivi by Hoffmann 22 
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 Caeoma 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 



form 



trichogyn 



ailed 



cells are not always present, but when they are they occur on both sexual cells. 

20 Pfeffer, W., Plant physiology. Eng. ed. Vol. I. pp. 199- l8 99- 

21 Dittschlag, E., Zur Kenntnis der Kernverhaltnisse von Puccinia Falcariae. 
Centralbl. Bakt. II. 28:473-492. pis. 3. figs. 6. 1910. . 

"Hoffmann, H., Zur Entwicklungsgeschichte von Endophyllum Sempermvi. 
Centralbl. Bakt. 32:137-158. pis. 2. figs. 14. 1911. 



i9i 2] CURRENT LITERATURE 437 

The life history of Endophyllum Sempervivi is peculiarly interesting 
because in that form the aecidiospores function as teleutospores. HoffmanK 
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 aecidiospore fuse and the subsequent processes are like those in teleu- 
tospores. The sporophyte phase is restricted to the aecidiospore mother cell 
and the two cells (aecidiospore and intermediate cell) formed from it. 

In both of these forms the binucleate cells arise from the fusion 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 his 
account of Phragmidium violaceum. 

In a short note Beauverie 23 reports further observations on the "cor- 
puscules metachromatiques " 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 Zach, 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 Gunncra (Halo- 
ragidaceae) by Schnegg in 1902, the genus has been included with those inter- 
esting angiosperms (as Peperomia) displaying an excessive number of nuclei 



mbry 



It was very desirable to study the 



situation more critically, and this has been done by Samuels^ for G. macro- 
phylla. 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 chromosomes was repeatedly observed to be 12. 
At the second division (four nuclei) two nuclei assume the micropylar 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 



2 * Beauverie, J., La signification des corpuscules metachromatiques dans les 
cellules de c6reales infestees par la rouille. Compt. Rend. Soc. Biol. 70: 461-463- 19"- 

24 Samuels, J. A., Etudes sur le d6veloppement du sac embryonnaire et sur la 
foundation du Gunnera macrophylla Bl. Archiv fur Zellforsch. 8:53-i 2 °- P ls - J"5* 
figs- 23. 191 2. 



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 complex enlarge after the entrance of the tube, 
but after fertilization they degenerate. 

Spermatogenesis was also followed, verifying the chromosome count, and 
showing a remarkable behavior of the pollen grain in frequently sending two 
tubes into the same style. Double fertilization was observed, so that the 



ght 



Samuels 



to the embryo sacs of gymnosperms. He also concludes that such a sac 
represents four megaspores in its origin. — J. M. C. 

Paleob otanical notes. — In 1906 Scott published briefly the genus Botry- 
chioxylon, and now there has appeared the full account.^ The genus is of 



sim 



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 26 has described a new species of the problematical genus Psygrno- 
pkyllum, 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^ 
Dicranophyllum, etc.) as a distinct group under the name Palaeophyllales, 
which may or may not have been the ancestors of the Ginkgoales. 

Dr. Stopes 27 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 (Aptiana, 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 

^ ._ i n 1 • 

2 * Scott, D. H., On Botrychioxylon paradoxum, sp. nov., a paleozoic fern with 
secondary wood. Trans. Linn. Soc. London II. Bot. 7:373-389. pis. 37~4i- i9 12 - 

26 Arber, E. A. Newell, On Psygmophyllum majus, sp. nov., from the Lower 
Carboniferous rocks of Newfoundland, together with a revision of the genus and 
remarks on its affinities. Trans. Linn. Soc. London II. Bot. 7:391-407. pis. 4 2 "44- 
fig. 1. 191 2. 



Marie 



Phil. 



Trans. Roy. Soc. London B 203:75-100. pis. 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 Maire. 28 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: (i) the individual evolution and the sexuality of 
the Uredinales, and (2) the relation of the Uredinales to their hosts and to their 
environment. 

The first part 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 
Ascornycetes, and on the existence of minute conidia possibly representing 
ancestral male cells among the Basidiomycetes. 

In connection with the discussion of those 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, ew-Uredinales ; I-II-III, ^to-Uredinales; O-II-III, bracky-XJredinales; 
O-III, /iy£0-Uredinales; O-I-III, 0/w-Uredinales ; I-III, catopsi-XJiedinales; 
II-III, hemi-Vredinales; II, />y/-0-Uredinales. Heteroecism and autoecism 
are expressed by the prefixes hetero- and auto- in the manner suggested by 

DUGGAR. 

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 role 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 



28 Maire, Ren£, La biologie des Uredinales. Progressus Rei Bot. 4:110-162. 



1911. 



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 mter- 
nodes, containing 14 Mexican and 17 Central American species. The first 
two groups are distinctly boreal and neither passes into the West Indies. The 
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, 29 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 
continued by a branch arising below the sporangium. Thus a sympodial 
system is built up as in Phytophthora. The fungus is peculiar in having a 
completely 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. 

A bee hive fungus.— Miss Beits* has described a new genus (Perky stis 
alvei) of "bee-hive fungus," which grows on pollen stored in the combs of the 
honey bee. The fungus is said to be "undoubtedly a normal inmate of the 
healthy bee-hive, and is, so far as is known, confined to that habitat." — J. M. C. 



2 * Butler, E. J., On Allomyces, a new aquatic fungus. Ann. Botany 25:1023 
io 35- figs. 8. 191 1. 

*° Betts, Annie D., A bee-hive fungus, Pericystis alvei, gen. et sp. nov. Ann. 
Botany 26:795-799. p[ s . 75, 7 6. 1912. 



Vol. LIV 



No. 6 



THE 














December 1912 



Editor: JOHN M. COULTER 



CONTENTS 



The Life History of Cutleria 



Shigeo Yamanouchi 



Alfred Dachnowski 



The Nature of the Absorption and Tolerance of Plants in 

Bogs 

Ingrowing Sprouts of Solanum tuberosum 

The Abortive Spike of Botrychium 

Plants Which Require Sodium 



G. Sttiart Gager 



O.O. Stoland 



W. J, V. Osterhout 



Briefer Articles 



Hairy 



Gautieria in the Eastern United States 



George F. Atkinson 
George F, Atkinson 



Current Literature 



The University of Chicago Press 

CHICAGO, ILLINOIS 

Agents 

THE CAMBRIDGE UNIVERSITY PRESS, London and Edinburgh 

WILLIAM WESLEY A SON, London 

TH. STAUFFER, Leipzig 
THE MARUZEN-KABUSH1KI KAISHA, Tokyo, Q*aka t Kyoto 



TLhe 



Botanical 0a3ette 



flbontblv 



Edited by John M. Coulter, with the assistance of other members of the botanical staff of the 

University of Chicago. 

Issued December J 6, J912 



Vol. LIV 



CONTENTS FOR DECEMBER J9J2 



No. 6 



I 

THE LIFE HISTORY OF CUTLERIA. Contributions from the Hull Botanical Labora- 
tory 163 (with fifteen figures and plates xxvi-xxxv). . Shige'o Yamanouchi 



THE NATURE OF THE ABSORPTION AND TOLERANCE OF 



IN BOGS 



Alfred Dachno 



INGROWING SPROUTS OF SOLANUM TUBEROSUM (with plate xxxvi and six figures) 



C. Stuart Gager 



THE ABORTIVE SPIKE OF BOTRYCHIUM. Contributions from the Hull Botanical 

Laboratory 164 (with twenty-one figures). O. O. Stoland ------ 

PLANTS WHICH REQUIRE SODIUM (with two figures). W. J. V. Oskrhout - 

BRIEFER ARTICLES 

The Perfect Stage of the Ascochyta on the Hairy Vetch. George F. Atkinson 
Gautieria in the Eastern United Stati . George F. Atkinson - 



CURRENT LITERATURE 



MINOR NOTICES 



NOTES FOR STUDENTS 



441 



5°3 



5*5 



52 
S3 2 



537 
538 



- 54C 

- S4<5 



Weslev 
each; 



Yearly sub- 



I 

The Botanical Gazette is published monthly. ^The subscription price is $7.00 per year; ™ P" ce 
of single copies is 75 cents. ^Postage is prepaid by the publishers on all orders from the United bt a tc , 
Mexico, Cuba, Porto Rico, Panama Canal Zone, Republic of Panama, Hawaiian Islands, Philippine 
Islands, Guam, Tuiuila (Samoa), Shanghai. «[ Postage is charged extra as follows : For Canada, 35 cams 
on annual subscriptions (total $7.35), on single copie 3 cents (total 78 cents); for all other counjnes in 
Postal Union, 84 cents on annual subscriptions (total $7.84), on single copies, 11 cents (total 86 cents;* 
f Remittances should be made payable to The University of Chicago Press, and should be m Chi ^ a |° for 
New York exchange, postal or express money order. If" local check is used, 10 cents must be added 
collection. 

The following agents have been appointed and are authorized to quote the prices indicatc 1\ V M liam 
For e British Empire: The Cambridge University Press, Fetter Lane, London, E.C., and ^» n * 
k & Son, 28 Essex Street, Strand, London. Yearly subscriptions, including postage, hi 1 - 

ingle copies, including postage, 3*. 6</. each. 
For the Continent of Europe : Th. Stauffer, Universitatsstrasse 26, Leipzig, Germany, 
criptio , including postage, M. 33 each; single copies, including postage, M. 3- 6 ° each; - Tnkvo 

For Japan and Koiea The Maruzen-Kabushiki-Kaisha, n to 16 Nihonbashi Tori anchorae, ^ • 
Japan. Yearly subscriptions m< iding postage, Yen 15.7; each; ..ingle copies, including pos g e > 
1 .75 each. .,. 

Claims for missing numbers should be made within the month following the reg ar month ot p 
cation. The p B expect to suppl missing numbers free when they have been lost in trans 

Business correspondence sh addressed to The University of Chicago Pre . Ch - 

Communications for the editor should b* Idressed to him at The Univ< of Chicag l tiicago » 

Contributors -e req ted to write cientific and \ er nam? with particular care, to US< L ttse 
tern of weights s measure ml in < ons to How the form sh n in the pages of the H 

iAZETTE. * 

Papers m exce i thin printed passes are 1 t accepted unless the author U villing to P*y^ e 

ot the a mt ig« 1 which case the number of page n the volume iscorr pondn v inert 

Illustrations are fum ed with cost to author only when suitable originals are ipplied 
i the sug^, itions r ie in the January number, 1907. ! be sent on appik ton. It advisaoi 

confer with the edi to illnstratioi required in an article to be offered. - nrieina? 

Separate in , must be order* n advan I publication. Twenty-five separates ot or K 

articles without covers will be supplied gratis. A table showing approximate cost of additional *epa* 



111 



0.1CAL 



A copy 



I 



aed on an order which a npanie the proof; a copy will be sent on request 

Entered Augtis? 21, 1 at the Past-office at Chicago, as second-class matter, under Act of Congress March 3, '• 






■ 






VOLUME LIV 



NUMBER 6 



THE 



Botanical Gazette 



DECEMBER 19 12 



THE LIFE HISTORY OF CUTLERIA 

CONTRIBUTIONS FROM THE HULL BOTANICAL LABORATORY 1 63 

Shig£ o Yamanotjchi 

■ 

(with fifteen figures and PLATES XXVI TO xxxv) 

Introduction 

This paper deals with nuclear conditions in Cutleria multifida 
J. Ag. and Aglaozonia re plans 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 Cutleria 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 £ 
iggested that Aglaozonia parvula is the asexual form 
ultifida y and that Aglaozonia chilosa is the asexi] 
utleria ads per sa. Church (6), with material from Ply 



form 



llaozonia reptans with Cutleria multifida, and Sauvage 
with material from Guethary and Banyuls, proved tl 

441 



44 2 BOTANICAL GAZETTE [December 



Aglaozonia melanoidea is the asexual form of Cutleria ads per sa. 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 Thuret (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. Derbes and Solier (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 Cutleria. 

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 187 5-1 876, observed the actual fertilization of 
the female gametes by the male gametes of both Zanardinia and 
Cutleria. In vessels containing both male and female gametes 
germination took place freely. There seemed to be no germination 
of the unfertilized egg. Reinke concluded that sexual reproduc- 
tion prevailed in Cutleria multifida and that Thuret must have seen 



i9i 2] 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 Cutleria, 
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 



Falkenberg 



demonstrated 



in 



veloping 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 
Cutleria multifida with Aglaozonia reptans, and Cutleria ads per sa 
with Aglaozonia chilosa. Four years later Janczewski (21), at 
Antibes, did with Cutleria adspersa 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 

of them were in the renroduction stage. The normal Cutleria 



some 



WOLLNY 



known 



not clear. 



The origin of the plant is 



made bv Church in 



1898 were from material collected in English waters. Church (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 Cutleria multifid 



female gametes 



rm 



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 and the 
zoospores of Aglaozonia produce Aglaozonia directly with no alter- 
nating appearance of Cutleria, Church concludes that Cutleria 
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, 



adspersa, a number 



same 



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 Cutleria 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 



Gulf 



Maroc 



remained 



nized. Sauvageau considers Aglaozonia melanoidea to be the 



adsp 



adspersa 



which he collected at Guethary (Basses-Pyrenees), he observed 
that the female gametes did not attract the male gametes. Th