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ON THE WATER RELATIONS OF THE COCONUT PALM
(COCOS NUCIFERA)— ON THE OIL PRODUCED
FROM THE NUTS—THE FACTORS ENTER- /"
ING INTO THE RANCIDITY OF THE
OIL, AND THE INSECTS AT-
TACKING THE TREES

Introduction by PAUL C. FREER

ON THE WATER RELATIONS OF THE COCONUT PALM
(COCOS NUCIFERA)

By EDWIN FINGHAM COPELAND

THE COCONUT AND ITS RELATION TO COCONUT OIL.

THE KEEPING QUALITIES OF COCONUT OIL
AND THE CAUSES OF ITS RANCIDITY

■ ■ m

By HERBERT S. WALKER

THE PRINCIPAL INSECTS ATTACKING THE COCONUT
PALM (PARTS I AND II)

By CHARLES S. BANKS

Reprinted from

THE PHILIPPINE JOURNAL OF SCIENCE

Published by the Bureau of Science of the Philippine Government, Manila, P. L

Vol. I, Nos. 1, 2, and 3, January, February, and April. 1906

86540

' MANILA
3URE\U OF PRINTING
1906

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ON THE WATER RELATIONS OF THE COCONUT PALM

(COCOS NUCIFERA)— ON THE OIL PRODUCED FROM

THE NUTS— THE FACTORS ENTERING INTO

THE RANCIDITY OF THE OIL, AND THE

INSECTS ATTACKING THE TREES.

Introduction by Paul C. Freer.

Investigations on the subject of the coconut palm (Cocos nucifera)
have been carried on in the Bureau of Government Laboratories for the
past eighteen months. The work has been divided into three parts and
brought to its present state by cooperation between several divisions of
the institution. It will be published in serial form in the Journal. The
first portion covers the water relations of the tree from the standpoint of
its physiology, by Dr. Edwin Bingham Copeland, who spent several
months on a plantation studying this question from an experimental
standpoint. The second paper covers the coconut in its relation to the
cultivation of the tree and the production of coconut oil, and includes a
study of the deterioration both of the copra and the oil by reason of
rancidity caused by molds and bacterial growth, by Herbert S. Walker;
and in conclusion there is added a study of the insects which attack the
plant, together with suggestions as to the best means of combating their
depredations, by Charles S. Banks and William Schultze.

By this union of the laboratory work, the study of this most important
tropical tree has been carried to an extent which not only will enable the
conclusions to be of great value to planters but which will also have a
scientific interest for those who are not immediately interested in coconut
production. 'One topic which is of especial importance is still under
investigation and not ready for publication. This is the study of the
germinating nut together with the transformation which the oil undergoes
during the growth of the embryo. This topic offers an opportunity for
the study of the enzymes in a germinating plant which is unsurpassed,
as the size of the seed of the coconut and the ease with which it is sepa-
rated into its various constituent parts brings a certainty of results not
to be encountered in other instances. This portion of the investigation
is now being followed in the chemical laboratory. When the serial on
the subjects mentioned above has been completed it will be published as
a separate reprint.

151051

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San Ramon Government Farm, where most of these investigations were
carried on, lies on the west coast of Mindanao 10 miles north of the town
of Zamboanga. It extends for about 2 miles along the seacoast and
toward the interior for 3 or 4 miles, to the base of a small range of
densely wooded mountains, which forms an admirable watershed.

Four small streams run through San Ramon from the mountains to
the sea. It is very probable ,that there is considerable underground
drainage as well, for fresh water may be obtained at a depth of 5 or (>
feet almost anywhere along the shore, even at the edge of the beach. At
present copra and hemp are the principal products of the farm, together
with a little cacao.

At the time of writing all the coconut trees used for making copra at
San Ramon were planted by the Spanish, but large numbers of new ones
are being set every year from selected seed, for which only the largest and
best nuts are taken. They are laid out on the ground in a sheltered
place and a small section of husk is cut from the top of each to afford a
more easy egress for the sprout. At the end of about six months' time,
when the sprout is from 2 to 3 feet high and the nut has just begun to
take root in the ground, it is ready for planting. For this purpose a
hole about 2 feet deep is prepared and the young plant is firmly packed
with the soil, so that the sprout stands erect and the top of the nut is C> to
10 inches below the surface. As a protection against wild hogs it has of
late been the custom to dig a pit 4 or 5 feet deep and to plant the nuts
at the bottom of this. The seedlings are set out in straight rows, allow-
ing a space of about 10 meters between each plant.

After planting, the young coconut requires very little care, except to
keep it free from weeds and the attacks of animals and insects, until it
reaches maturity. The average time before a tree begins to give a good
yield of fruit may be set at ten years. Instances have been known when
bearing commenced as early as the fifth year, but these are of rare occur-
rences and under exceptionally favorable circumstances.

The process in use for preparing copra is very simple. The nuts are
gathered by natives, who climb the trees, cut off the ripe or nearly ripe
fruit, and let it fall to the ground. No especial care is taken to prevent
damage by falling. The nuts are then piled in a heap and allowed to
stand for a few weeks before being opened. To remove the outer, fibrous
husk the natives make use of a heavy spearhead firmly sunk in the ground.
They force the nut down on the sharp point until it penetrates to the
shell, then, by a peculiar twist, strip off the husk, a portion at a time.
One man can husk, on an average, 1,000 nuts per day.

After being thus prepared the coconuts are split in halves by a couple
of sharp blows from the back of a bolo. The milk is allowed to go to
waste on the ground.

Drying.— The simplest method of drying the meat is to spread out the
halves of the coconut on large wooden trays, face up, in the sun. At

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night and in case of rain the trays are piled under a shed. After stand-
ing in the sun for two or three days the meat becomes partially dry and
has shrunken sufficiently to permit its removal from the shell. It is
then put hack on the trays and again exposed for a few days until it is
thoroughly desiccated.

The other method of preparing copra in use at San Ramon is to pile
the coconut halves, face downward, on a bamboo grating over a slow lire
of husks which is burning in a thick-walled brick kiln about (> feet high,
the whole being inclosed in a large shed. By this arrangement it is
sufficient to dry the nuts over night before removing the shells.

After heating the meat in the same manner during four or five hours
on the next day, it is ready to store for the market. "Grill-dried" copra
prepared in this way is not quite so liable to be attacked by insects and
molds, but on account of its dark color and slightly smoky flavor it is
considered inferior in quality to the sun-dried article.

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ON THE WATER RELATIONS OF THE COCONUT PALM
(COCOS NUC1FERA).

By Edwin Bingham Copeland.
(From the Botanical Section of the Biological Laboratory, Bureau of Science.

The work on Cocos nucifera (coconut), the result of which is reported
below, was performed at the Government farm at San Kamon, near
Zamboanga. Its purpose was to acquire as thorough a knowledge of the
physiology of this palm as the field conditions would permit, with the
especial hope that the results would be available for improving existing
methods of the plant' s cultivation.

Because of the remoteness of the place of work from any library or base
of supplies, the simplicity of apparatus which for the greater part is used
in investigating all phases of a plant's transpiration, the writer's famil-
iarity with this particular field, obtained in the preparation of earlier
papers, and because of the very great practical importance of understand-
ing this phase of the physiology of any plant important in agriculture,
the work was principally focused on the water relations of the coconut.
At the same time other phases of the tree's activity were not neglected;
and, in cases where it seemed worth while, notes not bearing on the main
subject are included in this paper. The value of artificial or natural
fertilizers was not considered, because this question is more in the domain
of the agriculturalist.

The divisions of the main subject are treated in the following order:
The root — its structure and growth, and the absorption of water; the
leaf — its structure, the activity of the stomata, and the transpiration ;
with final conclusions as to the fitness of the plant for its characteristic
habitat and suggestions as to its most advantageous cultivation.

THE ROOT.

The roots of Cocos nucifera have the two typical root functions — the
anchoring of the tree and the absorption of the water and mineral food
necessary for its maintenance and growth. In the absence of a taproot,
or of any great roots the hold of which in the ground can maintain the
rigidity of the trunk, the mechanical problem of the firm anchorage of the
latter finds a solution essentially different from that which we are
accustomed to encounter in the case of dicotyledonous trees. The base of
6

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the trunk is con vox or obeonical, and is usually buried for a depth of
hardly more than 50 centimeters. Its surface underground is almost
entirely covered with the bases of the roots. The latter are remarkably
uniform, about 1 centimeter in diameter, radiating from the tree on all
sides, each without much variation in its direction, and, so far as my
observations justify a general conclusion, for a normal distance of about
5 meters in iirm soil and 7 meters in sand. The lateral branches, what-
ever direction they may take with regard to the action of gravity, leave
the main roots with surprisingly uniform exactness at right angles and
are likewise on the whole straight, though less so in detail than the main
roots.

The old main roots are notable for the combination of elasticity 1 and
tensile strength shown by their powerful central steles, the cylinder of
xylem inclosing a "pith" with thick, lignified walls. The most con-
spicuous feature of the branches is their stiffness, for which the stele is
not more responsible than the hypodermis. I have never before, in any
plant, seen a rigidity on the part of the fine, absorbing roots which will
compare with that possessed by those of the coconut. The intimate
contact between the hard, firm roots and the soil is responsible for the
rigidity of the Cocos, as of other trees, but while in most, this contact is
centered about the base of the trunk, the Cocos has it disseminated equally
through the ground to a radius of 5 meters or more. The main roots act
as so many taut strands between the base of the trunk and the multitude
of fine points of attachment. The effectiveness of the coconut's system
of anchorage is perfect. The tree's favorite habitat is the seashore, where
it receives the unbroken force of the fiercest storms. Because of its
elasticity, the trunk very rarely breaks, and I have never seen one instance
of an uprooted coconut, the roots of which had not either previously been
killed or undermined by waves.

Eighty centimeters is not a very exceptional diameter for a well-grown
bole, though a majority fall below this size. The buried part of a stem
of this thickness will afford attachment for nearly 8,000 bases of roots
1 centimeter in diameter. Some of the main roots bear few or no
branches at all like themselves; others have 10 to 20, which rarely reach
a length of 1 meter or a diameter of 4 millimeters. The main roots
and these major branches bear numerous fine ones, 1 to 2 millimeters
in diameter, springing forth at right angles and having a rigidity which
has already been noted. These may be the ultimate divisions; or they
in turn may bear finer branches, at most a very few centimeters long,
about 0.5 millimeter in diameter; the life of the latter is transitory like
that of root hairs. A less ample system of branches is formed in sand
than in firmer ground.

Dead, distal parts of roots are replaced from the bases of the same roots

x Pfeffer, Pflanzenphysiologie, II, page 60, cites Sonntag, Landw. Jahrb. (1892),
21, 839 as authority for a stretching of 20 per cent by Cocos fibers, without
exceeding their limit of elasticity.

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in such a way that the new takes the place of the old, not only as an
ahsorhing organ but in the mechanical system as well. At the point
where dying hack ceases, a root, or frequently two roots, spring from
the end of the part which is still living. Their origin apparently is
internal, and, as is to be expected, from the outer limit of the stele;
the hypodermis of these older parts of old roots is so strong that the
young ones are rarely able to break through it, with the result that they
grow onward within the shell, sometimes for 30 centimeters or more,
before the hypodermis is sufficiently decomposed to permit their escape.
The direction of growth is then well fixed. From an observation of
exceptional cases in which the young root succeeded in rupturing the
hypodermis at its origin, and in which it then grew along or near it, it
appears that as a phenomenon of "correlation" the young root has the
same orientation-reaction as the one it replaces. The old hypodermal
shell is a most effective aid in this reaction.

My observations on the rapidity of the growth of roots have been un-
satisfactory. Many times I have marked off zones on apparently healthy
roots only to discover that they showed no subsequent growth. Some,
for a time, have elongated little or not at all, then for a few days have
grown vigorously, then stopped, without any apparent reason for the
irregularity :

The most rapid growth I have measured was 3.5 millimeters per diem. In a
month three roots grew more than 4 centimeters, but none as much as 5 centi-
meters. Sometimes, under favorable conditions, there may be a much more rapid
growth than I have been able to observe; 3.5 millimeters per diem is hardly
more than 1 meter per annum, a rate too slow to be accepted without more
evidence. A part of the roots I examined grew in water and a part in air sur-
rounded by soil. Those which elongated considerably in water at the same time
became more slender.

In large and rapidly growing roots a little elongation occurs in a zone 10 to 15
millimeters from the tip (not from the growing point), but in most cases it is
confined to the apical 10 millimeters. The root whose growth was most rapid
was 9 millimeters in diameter and had a cap 10 to 11 millimeters long. In two
days the latter grew 0.5 millimeter, 5 millimeters of root grew out of it, and the
zone immediately outside grew 1.5 millimeters. The length of the cap is some-
what greater than the diameter of the root, which is usually about equal to the
length of the growing zone when measured from the outside tip; therefore all
growth is generally within the cap. In this case the cap grew one-tenth as rapidly
as the root, and this seems to be about the usual ratio. In the ground the resist-
ance to the passage of the moving tip results in a continual tearing off of the
outer layers of the cap, these layers usually persist in the form of collars around
the root, and each is about as long as the cap; altogether they not infrequently
form a sheath along the whole younger part of the root. It is possible that
these collars or sheaths facilitate the absorption of water. When the root grows
without friction, in water, the whole outer portion of the cap, while retaining
its Iform, is occasionally sloughed off.

No response to any other directive agent is so conspicuous as the autotropism
of the coconut roots, of whatever order. The general level of the main roots is
maintained by a combination of hydrotropism and aerotropism, which I have not

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been able to analyze. A recent paper by Bennett- shows tluit many cases, at
least, of apparent aerot ropism are really liyilrotropie, ami the same is probably
true with the Coco*. The roots maintain a deeper level in sand than in heavy
soil. When the other stimuli are removed, a variable geotropism shows itself;
some, in water, grow straight ahead in as nearly horizontal a direction as it was
convenient to arrange them in the bottle; but the majority show a feeble positive
geotropism, the most rapidly executed curve being 40° in two days. The second-
ary roots are usually controlled by their autotropism alone. In heavy soil they
are sometimes more numerous on the upper sides of the main roots, probably
because of an induced geoauxesis, since the structure of the roots precludes the
probability of any direct locative influence of moisture on their origin, and the
pneumathode roots appear on all sides. In nature, no roots will grow to any
distance into water, nor into a level of the soil where water stands; and a rise
in the water level ultimately kills the submerged ones.

Root structures. — The stelar tissues of the coconut root offer very little
that needs description. The number of xylem rays is usually 40 or more
in the larger, 10 to 15 in the branch roots, 1 to 1.5 millimeters in dia-
meter, and fewer in the finer ones. In the young parts of the main
ones the pith is parenchymatous, with very thin walls. The latter begin
to thicken at a distance from the apex at which both hypodermis and
endodermis have reached their permanent state. They then become very
thick throughout, and are the chief source of the roofs great tensile
strength.

In cross sections, a very few cells behind the growing point, the pericycle
is distinguishable by the regularity and the large size of its cells. The
latter eventually become somewhat flattened tangentially, but they still
form a conspicuous layer in sections of old roots, as their walls remain
thin and colorless. The cross partitions are reticulate-punctured.

In very young parts of the root the endodermis can be identified only
by reference to the pericycle (fig. 2). Its cells begin to thicken at about
the same point as do those of the hypodermis, where the latter begins to
interfere with the absorption of water. The thickening takes place cell
by cell, rather abruptly in the individual cells, but without any uniform-
ity throughout the layer, so that in some sections a few will be found
well thickened, all the others still thin; while a little farther back most
of them will be found to be thick. Counting all the endodermal cells in
a section, an undue proportion of those which thicken late is directly
outside the xylem rays, where passage cells would be expected. However,
cells in this position are not infrequently among the first to thicken,
whereas scattered ones found elsewhere are often among the last. Con-
sidering the zone with reference to the hypodermis at which the thicken-
ing of the endodermis begins, it is evident that it is only as the water
travels obliquely up the root to the stele, and not directly inward, that
any of the cells remaining thin have occasion to serve in its passage. The
appearance of the old endodermis is shown in the accompanying figure
(fig.l).

2 Bot. Gaz. (1904), 37, 241.

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The outer part of the cortex, immediately underlying the epidermis
to a depth of three to six layers, is composed of cells smaller than the
deeper-lying ones. The walls of these, while they are in young and active
parts of the roots, are very thin, with a notably dense protoplasm. Sub-
sequently the walls thicken, those of the outermost cells iirst, until the
lumen is almost obliterated; they acquire a stony hardness and dark
color (figs. 3 and 4), thus forming a closed shell around the root,
protecting it against animals or fungi and having a mechanical value
already mentioned. The imperviousness of this shell to water is shown
by its effect on the epidermis and on the formation of pneumathodes.
The zone in which the hypodermis forms is that at which the root ceases
to absorb water from the soil.

The larger the root, the farther from the tip is this likely to be. In very
active ones the distance is as much as 5 centimeters; in those less active, but by
no means inert, having a diameter of 7.5 millimeters, it is found to be 2 centimeters
from the tip, while during drought it advances to a position well within the
firmly adherent part of the cap.

Between the hypodermis and endodermis the cortex is composed of
rather large cells, isodiametric or somewhat elongate longitudinally, with
thin, colorless walls, watery contents, and numerous intercellular spaces
(fig. 5). After the layers bounding it reach their final state, parts of the
interlying cortex become unequally thick walled and lignified. At the
basal end of old roots this intermediate cortex breaks, probably as a result
of tension between the elastic stele and nonelastic shell, leaving the
former loose inside of the latter.

The dermatogen is questionably distinguishable around the growing
point, even in most favorable sections. The epidermis is a transitory
tissue, dying when its connection with the inner part of the root is inter-
rupted by the development of the hypodermis. Its most conspicuous
feature is that the least diameter of its cells is the longitudinal (figs. 6-8).
No root hairs are ever formed, but the superficial area is slightly increased
by the breaking apart of the outer ends of the cells — a process which is
most evident in longitudinal sections. In a soil where the supply of
water is even moderately constant and ample the coconut root, with its
short absorbing zone and absence of hairs, would be regarded as but a
poor water gatherer, but when water is abundant, hairs are not needed;
and in a dry time their sacrifice is spared to the coconut. A tree whose
normal economy is planned on the absence of root hairs is comparatively
well able to survive periods of abnormal difficulty in obtaining water.

Pneumathodes (figs. 9-14). — The development of the hypodermal shell
so completely cuts off the interior of the root from all communication
with the outside that it can not carry on the limited exchange of gases
necessary for its respiration, and therefore it is obliged to develop special
breathing organs, or "pneumathodes." These are specialized roots which
quickly grow to a length of from 3 to 6 millimeters and then abruptly

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stop. The colls of the cortex then enlarge; tit first they keep their form,
but afterwards they become spherical and finally put out processes each
of which keeps in contact with a corresponding one from an adjacent
cell. Tli is enlargement of the cortex ruptures tin; epidermis and the
growth of the inner layers separates the outer ones, so that the epidermis
and outer layers Hare back from both ends of the swollen zone; its surface
is then mealy in appearance and white because of the contained air. As
the pneumathode ages, the cap and all the outer tissues beyond the open
zone slough off; the strongly lignified stele gives it stability and its sharp
point will protect it against mechanical injury, if protection is needed.
The cells of the open tissue necessarily promptly die, but their walls
remain firm, their surfaces become granular, and in this condition they
can not be wetted, so that the large amount of air contained between
them can not be displaced. The cells next to the stele, and those at the
base of the pneumathode — that is, those toward the parent root — enlarge
moderately and become spherical, and thus form intercellular spaces of
some size ; their surfaces also become granular and their walls very thick,
thus insuring the permanency of open aerial communication through the
pneumathode to the tissue of the parent root, which has the most abundant
system of intercellular 'spaces — that is, the cortical parenchyma.

Eoots which have suffered metamorphosis to serve as pneumathodes
have been encountered in many plants, and have been most thoroughly
studied in this part of the world, 3 but in all previously known cases they
are formed as a response to the wetness of the environment. In many
plants which grow in wet places, either frequently or invariably, pneuma-
thodes have become normal structures ; in many others, whose roots only
exceptionally find themselves where the supply of air is cut off by water,
pneumathode-like structures form as abnormalities. 4 In plants whose
habitat is such that pneumathodes have become a normal structure, the
roots which serve this purpose have usually acquired a negative geotro-
pism, adapting themselves to the direction in which the air is to be found.
This is true of Phoenix, whose pneumathodes, as figured by Tischler, 5 are
very similar to those of Co cos.

In distinction to all other known pneumathodes, those of Co cos are
demanded by the structure of the plant without regard to what its envi-
ronment may be. They form on roots in water, in firm ground, in loose
sand, and in the air. In soil containing free air, where the roots normally
grow and the formation of the pneumathodes is under the control of

"Karsten: Ueber die Mangrove-Vegetation im malayischen Archipel. Biblio-
theca botanica (1891), Heft 22.

4 The same is true of other parts of the plant as well. See Sorauer: "Ueber
Intumescenzen." Ber. hot. GeselL (1891), 17, 456, and my note on Haberlandt's
new organ on Conocephalus, Bot. Gaz. (1902), 33, 300.

5 Tischler, G. : Ueber das Vorkommen von Statolithen bei wenig oder gar nicht
geotropischen Wurzeln. Flora (1905), 94, 35.

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natural selection, it is of course a matter of indifference whether they
are above or below the parent roots; and no factor of the environment
has the least influence in determining the place of their origin or the
direction of their growth. They spring out at right angles, in all direc-
tions, and are straight. In water and in air they behave in exactly the
same way. Exceptional length and negative geotropism would be appro-
priate reactions on the part of the pneumathodes emerging under water,
but since the roots will not grow into water nor into soil without free air,
their formation in this situation must be too abnormal and too rare a
mischance for natural selection to have evolved any adaptation to it.

Absorption. — The same forces operate to draw water into the roots of
plants which afterwards cause its movement to the leaves. There are —

(1) Suction exerted by the tissues surrounding the xylem ends in the
leaves, and ultimately due to evaporation from the leaves under the
influence of the sun's radiated energy.

(2) The osmotic activity of the cells in the roots through which the
water passes. The former is the major factor, and its dominance is
more extreme in the coconut than in most plants. This is clearly shown
by two facts, the first one being that dead tips of roots for some time
continue to absorb water without any measurable decrease in the rate as
compared with that which was present while they were alive, and the
second one is that if the tips of active, growing roots are cut off and
immersed in water with not more than 5 millimeters of the cut end emerg-
ing into a saturated atmosphere, drops of water are not exuded from the
cut surface; it merely remains damp. When roots are cut or broken in
the ground, a gummy substance with a characteristic odor sometimes
exudes, but there is neither bleeding of water nor of a dilute solution.

However, water entering the roots through the living epidermis and
passing through living cells of the cortex to the stele must move under
the immediate influence of the osmotic activity of these cells; a .move-
ment of the water under natural conditions is thus effected because it is
constantly withdrawn from the inmost layers by suction. In this way
the turgor of the roots is a factor in the acquisition of water, even in
those which never bleed. The absence of bleeding only demonstrates
that the living cells of the root will not pass a part of their osmotically
active substance along with the water to the xylem; high turgor in the
roots and abundant water in the soil will not necessarily result in root
pressure.

The turgor in the pith, and in all except the fine outer cells of the cortex of
the absorbing zone of the roots, equals 0.25 to 0.3 normal potassium nitrate
solution. The walls are so thin that they wrinkle everywhere when plasmolysis
is extreme (fig. 5). In the fine cells, which later become the hypodermis, plas-
molysis is not visible in a less concentration than 0.5 normal; it is possible that
the denseness of the protoplasm, together with the osmotic pressure caused by
the cell sap, is responsible for this rather high figure. Plasmolysis is hard to detect
in the epidermis. The turgor usually, but not always, seems to be a shade higher

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than it is in the most of the cortex — about 0.3 normal. Jn the roots of moat
plants there is a slight but not appreciably interrupted increase in the turgor,
from the epidermis inward: but this increase is no necessary condition for the
ready movement of water, and in the Cocas we find in practice the lower turgor
to be internal.

Jn the youngest cells of the embryonal tissue which- can be plasmolysed the
limit is 0.5 normal. In the cap the turgor is for the most part 0.25 normal;
and in outside cells, as long as they are alive, it is no less. All these deter-
minations were made on roots which were apparently healthy and active.

In all my experiments on absorption by the roots homeopathic vials
were used, of such a size that when filled to the proper point with water
the weight was 40-45 grams. In the cork of each was cut a hole fitting
the individual root to be used. The latter was freed from the ground,
with the least possible damage, to such an extent as to permit the neces-
sary downward inclination of the tip. it was then washed, and all loose
remains of the cap were carefully removed from the part which was to be
within the bottle. To insure the absence of any open wounds the whole
exposed part of the root, except that which was to be within the bottle,
was smeared with vaseline. Water enough was used to immerse more
than the absorbing region of the root, and the bottom of the bottle was
kept low enough to prevent the water from touching the cork. The root,
with its bottle, was laid in half of a split joint of bamboo, to which the
appropriate slope was given, and the other half of the joint closed over it,
thus insuring cleanliness. The hole in the ground was covered with abaca
leaves to prevent unnatural warmth. All roots were left in this condi-
tion for one or more days before determinations of weight began.

After this time, when any initial disturbance in the rate of absorption
was assumed to have passed, the hole and bamboo were opened, the bottle
carefully removed, the root being touched by the bottle once to remove
any free drops, and then a weighed bottle of water was substituted, the
cork always remaining with the root. When all necessary care was
taken to prevent wetting the cork, neither bottle needed to be open for
more than five seconds, and the exposure of the root was even for a
shorter time. The chief error in this method of experimentation is
probably to be found in the variable amount of water adhering to the
root, but experience shows that the results are reliable to a limit of
1 centigram.

The chief facts I endeavored to ascertain with regard to the absorption
by the roots were the rate at which it normally takes place and the regular
diurnal variation, if any, which may be found in this rate. I have also
made some experiments on the absorption of solutions of potassium
nitrate.

With regard to the usual rate of absorption, as has been seen to obtain
for the growth, the first preliminary series of experiments demonstrated
that roots which to the eye appeared to be similar behaved very differently.
Nor was there correlation between vigorous growth and rapid absorption.

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I made four sets of experiments, with essentially the same results; here
it will suffice to give one of these.

This set was begun on January 11 and weighing commenced on Jan-
uary 13; but this beginning was made abortive by a rain which flooded
the whole site. A new start was made on January 17. The weights
given here are in centigrams, and are the average absorption for each day
comprised in the interval ending at the date at the top of the column :

Jan. 27. Jan. 31. I Feb. 3.

Root No.

Jan. 20.

Jan. 23.

III

» 10

VII

VIII

Fob. 10.

Mar. 1.

'•22

(8)

'139

« Pneumathodes appeared.

b Growth conspicuously rapid.

c Apparently dead or dying.

d Cap sloughed (absorption greater than figures show).

The root V was injured February 10, and was then cut with a sharp
knife without exposing the surface to the air, and the cut surface was
then immersed just as the uninjured tip had previously been; the total
subsequent absorption was only 63 centigrams. I had already satisfied
myself that practically no water can be absorbed by cut leaves, and the
same disadvantage from the experimenter's standpoint is presented by the
roots. It is of interest to note that while an open wound is very promptly
plugged, dead tips maintain their full absorbing activity for a considerable
length of time.

From these results I do not believe accurate conclusions can be drawn
as to the total absorption by an entire tree. The very great diversity in
the rapidity of absorption by the roots is but one of the reasons for this.
From a considerable number of measurements on different roots I can
say that, as a general average, the end of a main root, which, on anatom-
ical grounds, appears to be in a condition to absorb water, has about one-
sixth of the total surface possessed by all the root tips tributary to it.
If absorption were proportional to the exposure of living epidermis, then
the most rapid rate exhibited by any of these roots would indicate a total
daily absorption by a large tree of only about 24 liters. But there is no
such correlation between living epidermis and absorption, as is shown
by the behavior of dead roots and by the two mentioned in the preceding
table, the growth of which was temporarily most conspicuously rapid.
The immediate result of the rapid growth was a long zone of young tissue,
but in one of these cases the ensuing absorption was remarkably slow.

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The tips of the fine ultimate branches do not individually absorb with
sufficient rapidity to give me trustworthy differences in weight, and they
are too far apart to permit the use of several at once without a dispropor-
tionate increase in the water to be weighed. In a single instance I was
able to include three of them in one bottle of the usual size, and
then the observed absorption per unit of area was about three times as
great as I ever found it with the tips of the main roots. No far-reach-
ing conclusions are to be based on one fortunate observation ; but it does
show, as we must also conclude from the experiments to be described on
transpiration, that the total absorption can be much greater than meas-
urements made even on many tips of main roots would indicate. In one
experiment, the tip of a small main root 5.5 millimeters in diameter
showed a maximum rate for the time covered by eight weighings of
2 centigrams per diem.

Because of the -slight difference in weight to be determined, it was
useless, in undertaking experiments to show the relative absorption dur-
ing different parts of the day, to work with roots which had not already
shown themselves to be among the most active. In two sets of experi-
ments I have used such roots for this purpose. The result has always
been that the greatest relative absorption was observed during the after-
noon, and, so far as any conclusion could be drawn in such detail, during
the latter part of the afternoon. This difference, at different hours, is
usually less marked than it appears to be from the following table, which
shows the results for one day with the four most active roots represented
in the preceding table. The roots bear the same numbers. This experi-
ment began at 6.15 a. m. February 1. The figures are centigrams of
water absorbed during the preceding interval :

Root No.

Feb. 1.

Feb. 2,
6.15
a. m.

12.15 p. m.

6.15 p. ra.

II
V

VJI
X

5
14
10
12

11
21
19
22

5
16
10
17

From the fact that decidedly the most rapid absorption is during and
closely following the hours of most rapid transpiration, it is a reasonable
conclusion that the tree contains practically no store of water on which
it can easily and safely draw. However, no conclusion is justified as to
the total water actually contained in the path of the transpiration stream,
and therefore none as to the rapidity with which the water moves. The
water may rise slowly but the demand still be propagated rapidly.

My experiments on the absorption of potassium nitrate are open to
the same criticism as pertains to all of my other absorption experiments,

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namely, they had to be made on the tips of the main roots, which are
not the places where the process is most active. In working with these
solutions, trouble with red ants, which only exceptionally interfered with
experiments with pure water, became serious; as a consequence I was
finally obliged to seal all the tops of the bottle deeply with vaseline, thus
completely cutting off the access of air to the water in the bottle ; controls
with pure water showed that during the time of these experiments very
little if any interference with the absorption resulted. The investiga-
tions were made with the same roots which furnished the material for
the preceding tables, and they immediately followed the conclusion of
the period already reported. These results were scattered through too
many days to make a tabulated report feasible. In each case the absorp-
tion of the solution is compared with that of water during the preceding
period, which usually was of one day.

A solution of 0.1 normal reduced the rate of absorption for root VII from 40
centigrams (for the preceding twenty days) to 35 centigrams, Which is within
the limits of daily fluctuation. It was likewise questionable, in the case of main
roots, whether there was any reduction by a 0.2 normal solution; for instance,
with root TI the rate actually increased from 14 centigrams to 15 centigrams.
However, in the case of the three lateral roots, the rate fell from 51 centigrams
to 16 centigrams, and after two days they were evidently unsound.

The results obtained with 0.5 normal solutions were various. With root III
the decrease in absorption was only from 18 centigrams to 8 centigrams; tested
again with water, the rate rose to only 10 centigrams; another application of
the solution reduced it to 7 centigrams; and in water it again rose to 10 cen-
tigrams. With root I, the previous rate having been 7 centigrams, successive
determinations were 1 centigram, 1 centigram, and 2 centigrams; in water the
rate returned to 8 centigrams. With other roots the half-normal solution was
found to be sufficient to reverse the movement. Thus root VI, which had been
very regularly absorbing about 1 centigram, lost 2 centigrams, 3 centigrams,
and 2 centigrams. Root VII lost 1 centigram at one time and the three fine roots
lost at the same rate.

Immediately after losing at the rate of 1 centigram for four days, root
VII was put into a normal solution, and it then gained 8 centigrams
in one day. This result, which at first sight was surprising, is easily
explained. Water moves through the root in the direction in which it is
driven by the greatest pressure. Under ordinary circumstances this direc-
tion is inward because of the influence of the atmospheric pressure, the
pressure within being .less than that without. This may be expressed by
stating that there is a "suction" from the inside. In using the more dilute
solutions other agents must have acted together with the atmospheric
pressure — agents which perhaps were put in operation by the solutions
themselves; in this way the fact that the solution is absorbed will account
for the result. With the half-normal solution the osmotic pressure was
superior to the sum of the forces tending to make the water enter; as a
result, it moved outward. Other roots may have absorbed this 0.5 normal

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solution more readily, and so have been able to keep up a slow, inward
flow, for in proportion as it is absorbed it exerts no pressure. But the
normal solution was sufficiently concentrated to plasmolyse all the living
cells, after which it was possible for the solution to travel from outside of
the root into the xylem without being compelled to pass through any of
these. When this condition results there is no semipermeable membrane
in its way, and, concentrated as it is, it can exert no osmotic pressure.
If the half-normal solution were to cause general plasmolysis then it also
would enter freely and for the same reason.

The turgor of root VI was tested. This root had lost water to the half-normal
solution. A few cells in its cortical parenchyma were found to plasmolyse in
this solution, but the turgor of most of them was decidedly higher — about 0.7
normal. Some cells which did not plasmolyse even in such a solution did so in
a normal one. There was no active epidermis, for the hypodermis had devel-
oped so as to be only 1.4 millimeters behind the growing point, well within the
adherent part of the cap. The turgor of the cap was rather below 0.5 normal.
In the meristem the limit was slightly higher, but the regulation had not kept
pace with that in the cortex; and in the latter it was not what might have been
expected from the observations of Stange 6 on the roots of various European plants.

My experiments on the absorption of potassium nitrate conspicuously
show that the absorbing activity of the coconut roots is little interfered
with by a moderate concentration of the surrounding solution (up to at
least 0.2 normal). This obviously fits it for life in its typical habitat;
for, while the water in the soil near the sea, and even in the beach itself,
is not usually saline, because its mass movement is seaward, yet strand
plants are subject to inundation during storms, which sometimes bring an
amount of sea water about their roots which would be fatal if they were
more sensitive.

THE COCONUT LEAF.

Gross morphology and growth. — Aside from the cotyledon, which is a
very short sheath at one end with an enormous absorbing structure at the
other, the first leaves of the coconut are mere sheaths, resembling the bases
of later leaves, but entirely destitute of any lamina. These sheaths are
usually 4 to 6 in number, each being longer and less scale like than its
predecessor. In vigorous seedlings they sometimes appear at intervals of
less than one week, but as a rule the succession is slower. Their most
rapid measurable growth is immediately after they emerge from the nut.
The transition from sheaths to leaves may be abrupt ; or there may be one
or two, the upper part of which, after splitting, bends outward, like the
rachis of a leaf, but develops no blade.

The succeeding leaves, 2 to 6 in number, do not become pinnate, but
develop a lamina, which splits down the median line, sometimes merely
forming a notch, but usually extending more than half of the length of the

6 Stange, B. : Beziehungen zwischen Substrat-concentration, Turgor, und Wachs-
thum bei einigen phanerogamen Pflanzen. Bot. Zeit. (1892), 50, 253, etc.

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blade. The most rapid growth of the later of these leaves occurs at a
period which is a week or more after their emergence. They are plicate
in vernation, but the folds are shallow and are almost or entirely smoothed
out when the leaf is fully expanded. The result of this is an increase in
the area of the leaf, without a corresponding growth of its margin ; and
this, in turn, causes it to become convex on the upper surface and to curve
outward, whereby its exposure to light is materially increased, and the
stomata-bearing nether surface is protected against wetting by rain. The
first ones of these split leaves are apparently sessile, with blades about 20
centimeters long; the later ones are short stalked, and the length of the
blades may exceed 70 centimeters.

The transition from split to pinnate leaves is a gradual one. At first
only a few of the lowest folds separate, the appearance of the greater part
of the lamina remaining like that of one of the merely split leaves imme-
diately below it; in succeeding ones the pinnate lower part increases at
the expense of the compact upper part until the latter ultimately disap-
pears. The number of leaves sharing in this transition varies consid-
erably, 6 being a common one. In length they may be from less than
1 meter to a size considerably larger. The earlier leaves are all short
lived, and, as each succeeding one is larger than the preceding, their
dimensions on a young tree are constantly increasing. In cultivation the
nuts are germinated collectively and the seedlings set out in their per-
manent places during the split-leaf stage. The increase in diameter of
the mass of the bases of the petioles is constant, and as the leaves have
sheathing bases, as the tree grows, the latter rise into the air as a false
stem, resembling that of the banana or abaca; this false stem reaches a
height of about 150 centimeters before the real stem or trunk is visible.
For several years after the appearance of the trunk, the leaves continue
slowly to increase in number and in length. When the first nuts appear,
at an age of from five to nine years, the tree is bearing at least twenty
leaves. Even after this time there is usually some increase in their size ;
in vigorous old trees the number is 25 to 30 or even 35; each of these
leaves is from 5 to 8 meters in length, with about 80 pairs of pinnae, large
and small.

The following table shows the rate of growth of the scales and split
leaves of a number of seedlings. The measurements are from a mark
on the lowest visible sheath, the husk not being dissected away ; therefore
there may have been some of the oldest sheaths invisible and not repre-
sented ; and the growth being basal, the mark on the lowest visible sheath
can record no growth. The entire elongating region is always within the
protecting sheaths of the lower leaves, so that zones marked on any visible
part of the leaf retain their exact intervals. Leaf No. I is the one which
was marked, the others being successively younger. The numbers in
parentheses represent total length ; the others, the growth during the time

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elapsing since the preceding measurement. Blanks indicate no growth.
All measurements are in millimeters. "G" is the girth :

Leaf No.

Deo. 15.

Dec. 22.

Dec. 29.

Jan. 5.

Jan. 12. ; Jan. 19.

Jan. 26.

(9.5)

I 2

(11)

(22)

5
20

1 3

( 1

(65)

10
28

(11)

1 2

(7) ! '2.5 ! 1

(18)

H \ 3

(12)

11 i 11

8 !

i 4

8 i

'f '

(11)
(37)

III i.

2
3
4
S

(66)
(67)

4
23

2
14
44

2
11
46

1 !
4 i

(180)

IV !i J

(20)
(40)
(29)
(56)
(103)
(67)

v \

i
1

VII :

VIII

2
3
4
5
G
1
2
3
4
5
6
G

/ 1
2
3
4
5
6
7
8

, G
1
2
3
4
5

. G

7
38
39

2
23
36

2
20
41

(89)
4

1
8

38
43
3

2
3
29
54
4

13
53

(28)
(16)
(46)
(80)
(109)
(120)

16
51

18
53

14
53

(142)

48
49
2.5

2
51
56

4.5

33
65

(28)
(5)

(46)
(103. 5)
(204)
(469)
(586)
(399)

7
109
71

28
81

1
33

3
4

(352)

• 92

(60)

(38)
(126)
(390)
(633)
(342)*

(57.5)

25
69

2.5

6
64
3

11
21

Under fair conditions each leaf of a young tree grows decidedly more
rapidly than the next older one, and in seedlings which are of the size of
the ones mentioned above, several leaves grow rapidly at the same time.
While the plants represented in this table were under observation the
growth of their roots was prevented by frequent moving. This injury
was reflected by a slower development of the shoot before the measure-
ments ceased. Each leaf had less than the normal advantage over its

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predecessor, and its period of rapid growth was abnormally short, so that
in most cases only a single leaf was growing vigorously on each seedling.

Working as I did in the open and therefore largely depending on nature
for modifications of the environment, it was very difficult to secure any
reliable data on the influence of the individual factors of the environment
on so slow a process as growth. Of the plants represented in the fore-
going table, those with even numbers were watered twice daily during the
first two weeks. As compared with the alternate ones, which were placed
in an otherwise drier place and which received as much as 1 millimeter
of rain but once in fourteen days, the growth of the watered plants was
much slower, but the relative rapidity of development was not affected by
reversing the positions during the succeeding fortnight; from which it
appears that the difference was inherent in the individuality of the plants,
and that it is a matter of practical indifference to seedlings of the ages of
the ones which I was observing whether they be given much water or very
little. Observation of a seed bed where more than 5,000 nuts were placed
to germinate justifies this conclusion. Differences in the exposure of
different parts of this bed were not reflected in the growth of the seedlings.
Until the area of the leaves permits an appreciable transpiration, the nut
must contain all the water the seedling normally demands for its growth.
Tf the husk is entirely dry the roots do not emerge from it, but this may
as well be due to the extreme toughness of the dry husk as to the abnormal
loss of water from the roots and to any inability on their part to absorb
water. After this time a removal of the roots or a prevention of their
growth by frequent moving stunts the development of the seedlings, and
no amount of water will altogether obviate this result, though, of course,
the injury is fatal only when excessive dryness or some other cause pre-
vents the development of new roots. Whether the injury to the growth
of the shoot of well-watered plants is correlative 7 or because enough
water can not be absorbed is uncertain, but in either case the leaving of
the seedlings in the germinating bed after the nut's supply of water ceases
to satisfy all demands, will result in injury when they are transplanted,
even under the most favorable conditions.

The available moisture determines the rate of growth of the leaves of
older plants to the practical exclusion of the influence of all other factors.
My work on these older plants began after the influence of the dry season
was seriously felt. Drought interferes first with the growth of the young-
est individuals, the larger one suffering less, in proportion to the depth
and extent of their root systems. The following table shows the growth
of one plant (A) the development of which had practically been arrested,
and of another (C) which up to the time of observation had compara-
tively been but little affected. In each case a leaf tip barely protruded

7 Kny: Correlation in the Growth of Roots and Shoots. Ann. of Bot. (1894),
8, 265. Townsend: The Correlation of Growth Under the Influence of 4 Injuries,
Ibid. (1897), 11, 509.

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from the mass of bases. A stout stake was driven into the ground until
its fop was exactly even with the tip of this leaf. All measurements given
are from the top of this stake and are expressed in millimeters. Incre-
ments since the preceding measurements are indicated by boldface type.
The heights of the stakes were, respectively, 500 and 1,320 millimeters.
The experiments began on February 8 :

Date.

Lea

f A.

Lea

f o. •

Feb. 10
Feb. 17

1
2. 5

190

1.5

150

Feb. 22*

306

110

Feb. 24

(16)
88

(13)

<S5

Mar. 1

404

Mar. 10

311

228

550

140

Mar. 17>»

494

183

665

115

Mar. 23*

659

1«5

772

107

Mar. 30

784

125

885

113

Apr. 6<»

895

111

1,004

110

11 Plant watered.

'> Leaf begins to expand.

« Watered last, March 20.

d Marked part of both leaves expanded.

The following contains a more detailed tabulation of the growth of
these two leaves for a portion of the time included in the preceding one
and shows the relative growth by day and by night. All measurements
given are the increments during the preceding periods :

Date.

Hour.

Leaf A.

Leaf C.

Day.

Night.

Day.

Night.

Feb. 22
Feb. 23

Feb. 24

Feb. 25
Mar. 10

Mar. 11

Mar. 12

Mar. 13

6 a. m.
9 a. m. a
9 p. m.
6 a. m.
12 m.
6 p. m.
6 a. m.
6 p. m.
6 a. m.

___ __

1.5

11.5

1.5

15.5

6 a. m.
6 p. m.
6 a. m.
6 p. m.
6 a. m.
9 p. m.
6 a. m.

a This interval follows the first watering of leaf A too promptly for the growth to be at all
normal.

A few measurements at other times agreed entirely with those given
above in demonstrating that the measurable growth very largely took
place at night, the diurnal growth of the plants which were seriously

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suffering from drought falling to nil. Indeed, a slight but unmistakable
shortening occurred on certain of the days of observation. The reason
for this strikingly unequal distribution of the growth is that the active
transpiration during the day creates an internal scarcity of water and
reduces the content of that liquid in the plant to such an extent that any
considerable enlargement is impossible. A similar, but much less pro-
nounced, daily periodicality of growth is reported for the bamboo, 9 10
correlated with the relative humidity. Every factor which contributes
to the more active transpiration during the day is also in part responsible
for the cessation of growth. 10

It is a very common practice in Mindanao to plant coconuts and abaca
together, in the expectation that the abaca will support the commercial
undertaking until the coconuts mature. This may be expedient, from a
business standpoint, where the cost of clearing is the chief item in the
establishment of a plantation; and after the first two or three years the
coconuts suffer less than the abaca in this competition; but the maturing
of the former is delayed by probably two years, and the trees are never
as robust as those which were better illuminated from the start. The
ultimate diameter of the trunk of a palm is determined in its youth. 12

The heliotropism of the coconut is illustrated by the well-known dis-
position which trees along the- beach have to bend toward the water (fan-
tastically ascribed to the tree's love of the sea) and by the tendency of
those around the outer edges of a grove to lean outward in every direction.
This heliotropism is the more interesting because the actual growing
region, where the curving takes place, is deeply seated below the visible
tip and covered by the bases of many leaves.

The negative geotropism of the trunk causes a prostrate tree to turn
upward with a curve the radius of which often does not exceed twice the
ultimate diameter of the trunk. This abrupt curvature is rendered pos-
sible only by the harmonious reaction of many growing leaf bases, those
beneath developing more and those above less rapidly than the ones in
the middle. Each leaf base executes its own appropriate curve. These

9 Lock: Annals Bot. Gard. Peradeniya (1904), 2, 211. Not seen.

10 Kraus (Das Lilngenwachsthum der Bambusrohre, Ann. Jard. Bot. Buitenz.,
1895, 12, 196), working at Buitenzorg, With almost daily rain, found the diurnal
retardation of the growth of bamboo slight compared with that reported here for
Cocos.

11 At least the larger proportion of the experiments which are supposed to show
that light exerts a direct retarding influence on the growth of stems and leaves
are questionable because they do not exclude the possibility of the direct influence
of the illumination on the transpiration and a consequent indirect retardation of
growth. While the immediate effect of light is to retard growth, adequate
illumination is of course eventually indispensable for the healty development
of the plant.

12 The nuts in a seed bed are usually placed horizontally because the trunks
grown from such seeds are supposed to be stouter. Drude, in Natiirlichen Pflan-
zenfamilien, 11, 3, 3, states that some palms, such as Sabal and Ceroxylon,
normally develop stouter trunks if their earliest growth is horizontal.

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reacting bases are organically connected only by means of tissue which
must completely have ceased to grow (it is not available for measure-
ment), and the harmony of the entire reaction is no evidence of any
communication between the units concerned in it. 1 ' 1

Anatomy of the leaf. — In describing the anatomy of the coconut leaf
nothing need be said about the iibro-vascular tissue except that the finest
longitudinal veinlets are hardly more than 0.1 millimeter apart, so that
water in order to reach any cell of the parenchyma only needs to pass an
exceedingly short distance by osmosis. The structure of the individual
veins and veinlets offers no peculiarities.

The most striking structure in the leaf is what may be called the
"hinge/' Eunning ventrally for its entire length along each side of the
midrib of the pinna is a narrow strip, sharply differentiated from any
neighboring living tissue by its colorless contents. A crease along the
middle of each of these strips makes the leaf thinner at this point than
anywhere else, the colorless hinge tissue occupying more than half the
thickness of the leaf but not entirely crowding out the green mesophyll.
The epidermis of the hinge, as seen in transverse section, is remarkable
for its exceedingly convex outer walls. The two accompanying figures
(15 and 16) make this structure clear.

Because of the convexity of the outer walls of the individual cells, the
wall of the epidermis, in this situation, as a whole is very much wrinkled ;
so that a bending or even a stretching can obviously be accomplished by
a very slight and easy bending of walls at right angles, without giving rise
to the uncompensated stretching of any one unit. Other parts of the
leaf have the thick outer walls practically plane, and as any bending would
involve the extension or direct compression of the whole of one of them
these parts are practically rigid. Therefore, the crease mentioned above
facilitates movement not only because it makes the leaf thinner at this
point but also because it increases the convolution of the walls and reduces
their resistance.

The active tissue concerned in the movements of the hinge is the color-
less mesophyll. Its cells are large, and they have thin walls which are
easily bent or even stretched. It is without intercellular space, so that
the slightest alteration in the volume of the individual cells changes that
of the entire tissue. The volume of the cells must obviously vary with
their water content. When the leaf is well supplied with water the cells
of the hinge are distended to their full capacity and it is open, thus hold-
ing the two sides of the pinna as far apart as possible. When the supply
of water is insufficient the reverse takes place. By this means the expo-
sure of the pinna to the rays from the sun or sky is lessened and a "dead
air" space, though usually a very imperfect one, is formed under it. In
both of these ways the further loss of water is checked.

When the pinna is losing water faster than it is being furnished from

13 Cf. my paper, "The Geotropism of Split Stems," Bdt. Gaz. (1900), 29, 189.

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below, the hinge responds before the cells of the green mesophyll begin
to suffer. The explanation is as follows: All the cells hold their water
through the osmotic activity of their contents; the turgor of the
chlorophyll-bearing cells is such that plasmolysis begins in about 0.5 nor-
mal potassium nitrate, while the cells of the hinge begin to plasmolyse in
less than 0.3 normal, as a consequence the latter will lose the greater
amount of water in the shorter time, thus causing the hinge to close.

The actual behavior of the hinge is sufficiently illustrated by the follow-
ing table, which gives the distance, in millimeters, between the edges of
the two pinnae, each measured 20 centimeters below the tip, at intervals,
for two days :

Leaf.

Dec. 7.

7 a. m.

8 a. m.

Z a. m.

10 a. m. 11 a. m.

12 m. 1 p. m.

A
B

20.3
25

17.5
21

15 i 13

20 18

12.5
17

12. 5
16.5

Leaf.

Dec. 7.

p. m.

Dec. 8.

2 p. m.

3.30 p. m.

5.10

6.30 a. m.

7.30 a. m. i 8

20.3

25 1

.30 a. m.

A
B

13
16

17. 5

1
2

7
1.5

20.3

20
23

Leaf.

A
B

c. 8.

Dec. 9,
6.30
a. m.

9.30a.m.

10.30

a. m. i

12 m.

1 p. m.

| 2 p. m.

4 p.m. 5 p. m.

16.5
21

13.5 ,

18.5

12
16

13
16.5

12.5
15

13.5 ■ 16.5
17 21

20.5

As the accompanying records show, 14 the months between November
and April were exceedingly dry at San Eamon. The influence of this
climatic condition on the behavior of the hinge is shown by the following
measurements, in millimeters, made on the same leaves at the same points
one month later than the date of the preceding table :

Leaf.

Jan. 11.

Jan. 12,
7 a. m.

18
23

Feb. 8,

6.30 a. m.

7.30 a. m.

7 a.m.

17
21

A
B

18
23.5

The surface of leaf B was moist on the morning of January 11, and this
fact demonstrated that its failure to open as widely as it did a month

14 See hygrometric readings appended.

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before had become chronic. This was due to the prolonged drought and
not to the age of the leaf, for in seasons of fair precipitation the pinna?
lose none of their original power of expansion, at least until they are
much older than the ones measured in these experiments.

Aside from the hinge, the mesophyll is differentiated into the green
assimilating, and what, in deference to custom, I will call a water-storing
tissue. The latter is composed of two layers of cells, immediately beneath
the upper epidermis. The upper of these layers has the cells elongated
at right angles to the length of the pinnae, as is shown by figs. 17 and 18,
while those of the inner layers are considerably deeper and larger. Both
are almost perfectly transparent and their contents consists almost
entirely of water. They form no inconsiderable part of the volume of
the leaf. Their walls are not sufficiently thin either to be collapsible or
to stretch very easily, so that only an insignificant part of the water which
they contain can ever be available to replace any loss on the part of other
cells. They are primarily rather to be regarded as a screen, the function
of which is to mitigate the injurious effects of too extreme insolation on
the underlying green cells. The same is true of the thick-walled, so-
called water-storing tissue of many other plants.

The green mesophyll is but feebly differentiated. There usually are
two layers which may properly be termed palisade cells, and about four
more, the cells of which are irregularly placed; but the leaf throughout
is too compact for any tissue appropriately to be designated as spongy.
The turgor of the assimilating tissue is equal to about 0.5 normal potas-
sium nitrate.

The cells of the epidermal tissue are approximately isodiametric in
surface view, their least diameter being the depth. They are devoid of
chlorophyll, and hyaline. Their turgor is about that of the hinge cells,
but their heavier walls prevent any considerable variation in their water
content. The outer wall of the upper epidermis is 6 to 7 /* thick ; that of
the nether, 5 /*. The surfaces are glabrescent.

The stomata of the coconut leaf are confined entirely to the nether surface,
where they number about 145 per square millimeter. They average in size about
30 by 33 p with an area for the pores and for both guard cells of 740 fx square.

As the accompanying drawing of the transverse section (fig. 19) shows,
the stomatal apparatus is practically superficial, the back of the guard
cell being sunk just enough to make room for a hinge in the wall outside
it and to permit it to move without interference from the thick, outer
wall of the epidermis. The mechanism is exactly that of Schwendener's
type of Amaryllis. 1 * 10 The back wall of the guard cell is so thin that it
collapses and wrinkles in plasmolysis. The ventral half of each, namely,
the one next to the pore, is strengthened by the powerful ridges of

10 Schwendener: Ueber Bau und Mechanik der Spaltoffnungen, Monatsber. Akad.
(I. Wiss., Berlin, 1881, 833.

10 Copeland: The Mechanism of Stomata, Ann. of Bot. (1902), 16, 33$.

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entrance and exit and by the neighboring, comparatively heavy parts of
the wall. Anticlinal walls never strike the guard cells midway. A more
detailed explanation of the mechanism of these stomata would be super-
fluous here. However, there are some interesting features about their
turgor and their behavior under changes of illumination and with the
gradual withdrawal of their water which render it worth while to intro-
duce some measurements. The agent employed by me to withdraw the
water was potassium nitrate. The solutions were 0.3 normal, 0.5 normal,
and normal. Measurements are in microns:

Stoma:

Length _

Width ...

Pore, width_

Ridge of exit

In pure ; 0.3 nor- j 0.5 nor- 1 nor-
water. ! mal. i mal. mal.

35
30
3

28
1.2

34
20

C.i

The normal solution plasmolysed the guard cells and caused the contents of
other epidermal cells to collapse until they occupied hardly half the previously
visible area. Remaining ten minutes in this solution killed many of the former,
and others opened the pore only after the solution was replaced by water and the
slide exposed to the direct sunlight. The two stomata described below half
opened in water and completely in the sunlight. Measurements are in microns:

Leaf.

Direct
sun.

Obscure light.

Microscope stage.

15 min-
utes.

31
4

30
3

75 min-
utes.

10 min-
utes.

15 min-
utes.

31
4

31
3

A
B

Width:

Stoma _____

32
5

30.5
5

30
0.5

30.5
3

30.5
2

Pore

Width:

Stoma ._

Pore _

It appears from these measurements that seventy-five minutes in quite
diffuse light affects the degree of opening of the pore about as much as
does immersion in 0.5 normal potassium nitrate solution. The recovery
of turgescence with better illumination occurs with amazing promptness
when one considers the great change in turgor which precedes and causes
it. In this experiment, as is always necessary when stomata are under
prolonged microscopic study undertaken with sufficient care to permit of
accurate measurements, they are immersed in water. When they are in
the natural condition on the living plant they respond much more quickly
and thoroughly to the withdrawal of the light, as is shown by experiments
to be reported below, in which the rapidity of transpiration is determined
by the cobalt test.

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While all recent writers on the subject have assumed that changes in
turgor are responsible for the changes in turgesccnee with variations in
the illumination, it has never, so far as 1 am aware, been demonstrated
that the turgor really does vary. 17 J myself have tried to measure such
a change with divers plants, but without success. However, with the
coconut it is easy to determine that the turgor is much higher in light
than in darkness, though the actual differences are rather inconstant.
The turgor of a single pair of guard cells can be demonstrated to change
during a prolonged experiment; but as this involves plasmolysing the
pair at least twice, and, as a rule, subjecting it to several strong plasmo-
lysing solutions, each of which must be given time to act, the cells are
likely to suffer changes from this treatment. The evidence taken from
the observation of many different stomata, in their natural condition, at
different times of day, is more valuable.

The turgor on sunny afternoons is usually about equal to normal potassium
nitrate. Sometimes it exceeds even this high figure. Thus at 3.30 p. m. Novem-
ber 25 these measurements, in microns, were made:

Pore, width .

0.5 nor-
mal.

0.7 nor-
mal.

1 nor-
mal.

Closed.

While the particular stoma under observation was not measurably open, about
one in five on the section was open to the extent of at least 1 /u, the plasmolysis
of any guard cells being very doubtful; but when the normal potassium nitrate
was replaced by glycerin, plasmolysis was evident everywhere, and all stomata
were closed. If they were examined early in the morning the guard cells were
usually found to have their turgor equal to somewhat less than 0.7 normal potas-
sium nitrate but rarely below 0.6 normal. In direct sunlight the increase is an
immediate one.

The action of prolonged darkness is very different from that of the
mere nocturnal lack of light. A leaflet was kept in darkness, inside a
wooden cylinder, for ten weeks, at the end of which time its turgor, as
compared with that of a neighboring pinna under ordinary conditions,
was:

Name.

From
darkness.

From nor-
mal leaf-
let (in
morning).

Epidermis.

0.5

0. 9-1.0

0.25-0.3
.6 - .7
.7 - .6

Guard cells, _

Parenchyma __ _

17 The term "turgor" is used to express the osmotic pressures of the internal
fluid of a cell. On the other hand, the expression "turgescence" applies to the
strain resulting from the interaction of the force of the osmotic pressure (the
diffusion tension of the solute) on the one hand and that of the resilience of the
cellulose membrane on the other. Copeland, Ann. of Bot. (1902), 16, 330.

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In my paper, "Ueber den Einfluss von Licht und Temperatur auf den
Turgor/' 18 I showed that in leaves growing or grown in darkness the
turgor is higher than in normal ones; but the pinna of the coconut which
1 had under observation did not, at least in area, grow during the
experiment, therefore the explanation in this case must be a different one.

TRANSPIRATION.

Three general methods have been used in research on the transpiration
of plants : First, measuring the water absorbed by the subject of the ex-
periment; second, determining the loss in weight of the subject and its
container; third, ascertaining the amount of transpired water after it
leaves the plant. I have used all 'of these in my work on the coconut.

The first method is of the least value because it does not directly meas-
ure the transpiration, and because the amount absorbed and that given
off in a given time are not necessarily equal. I employed it in some pre-
liminary experiments only, when my equipment did not permit the use of
either of the others. As the pinnae which served as subjects always lost
weight almost from the beginning of the experiments, absorption being
less rapid than transpiration, the method is inapplicable when any meas-
ure of accuracy is desired. It will, of course, be understood that all
ordinary means of keeping the absorption normal were employed.

In all experiments on the transpiration of this plant in which the
subject is to be weighed the use of single pinnae is practically compulsory,
for even young seedlings are so heavy that the loss of water from the
limited leaf area in such time intervals as one hour would escape notice.
Entire leaves have the same disadvantages as do pinnae, and besides they
are most unwieldy. When it can be used at all, the determination of
the loss of weight of subject and container is the most reliable method of
ascertaining the transpiratory activity of any plant, and when, as in this
case, the use of whole plants is impracticable, it is usually feasible, with
proper care and precaution, to be sure that isolated parts of them behave,
at least for some time, as they would in their natural positions. I have
used this method in the larger part of my work, but, in contrast to expe-
rience with other plants, have found it quite impossible to make single,
isolated pinnae of the Cocos maintain the normal rate of transpiration
for more than a very short time. Leaves cut under water, with the cut
surface at all times protected from exposure to the air, approximated
normal transpiration but little if at all more closely than those treated
without this care. This has repeatedly been my experience. One rather
extreme illustration will suffice to demonstrate it: The cut surface was
never exposed to the air. The first weighing was immediately after cut-

18 Dissertation, Halle, a. S., 1800.

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ting. The loaf was exposed to direct sunshine during the greater part of
the time:

Interval.

Loss of
weight.

Loss i>er
minute.

Minutes.
6

Grain.
0. 15

Gram.
0. 025

.17

.013

.26

.005

310

.70

.002

The average loss per minute during the last interval was only 8 per
cent of that during the first. Transpiration does not usually cease so
promptly, and the relative loss is less, the longer the first period is made.
It is a general rule, in experiments of this kind, to permit the subject to
stand, for a time after cutting, and. thus to become accustomed, to its new
conditions before observations really begin. If this is done with Cocos
the rapid initial transpiration can not be observed, and thus the abnor-
mality of the results obtained must escape suspicion. Many of my tables,
which seemed satisfactory when made, are valueless on this account.
When the transpiration of a leaf varies during a single half day by 92 per
cent of its maximum activity, independently of any change in the environ-
ment, it is obvious that any modification of the latter must have results
which are comparatively too insignificant to be studied with any con-
fidence. Therefore, I was forced to seek a means of preventing the usual
reaction to the cutting of the pinnae.

The water in which cut pinnae stand ceases to be clear, becoming a pale,
often opalescent, brown. This is sometimes evident within half a day
after cutting, but usually it is not seen until a day or more has elapsed. 19

Suspecting that an exudation from the cut surface (though none was
visible) might be preventing the absorption of water, I tried renewing the
cut. It was doubtful if the transpiration was accelerated ; certainly such
acceleration was not enough to be applicable in drawing any conclusions.

It was shown by Janse 20 that, while boiling a part of the path of the
transpiration stream ultimately results in interference with the movement
of water, this result is not immediate, and is due to changes in the part
remaining alive, not in that killed. It occurred to me that boiling the
bases of the pinnae might prevent the checking of their absorption for at
least a few days. As a matter of fact, the cessation was less immediate
and less complete in pinnae so treated than in others, but it was still so
great that the results obtained by this method alone are far from satisfac-
tory. They are shown in the next table.

10 This is a conspicuous exception to Sachs's statement that nothing escapes from
such cut surfaces into water.

20 Janse, J. M. : Die Mitwirkung der Markstrahlen bei der Wasserbewegung im
Rolz, Jahrh. wiss. Hot. (1887), 8, 1.

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The fact that neither renewing the cut nor killing the lower ends of
the pinnae prevented the practical cessation of the transpiration would
suggest that this cessation is due to some reaction on the part of the
stomata, hut this can hardly he true, for, as already noted, the cut pinna*
lose weight during the experiments. The only explanation J can suggest
for the persistent refusal of the cut pinnae to absorb water at least as
readily as they normally secure it from the rachis of the leaf is that a
pressure of less than one atmosphere within the tracheae is a condition
for the ready movement of water through them, and that offering water
to the pinnae at a higher pressure than the usual one, instead of making
them absorb more, is in itself the cause of their absorbing less. I am not
ready to support this suggestion here, and know that it is contrary to the
generally accepted opinion that water travels through wood with equal
readiness regardless of whether the motive force is applied as a pressure
(above one atmosphere) or as a suction (less than one atmosphere). It
seems to me that this may be true in some cases and not in others, depend-
ing, for one thing, on the amount of air in the conducting elements.

Determining the water given off by leaves by absorbing and weighing
it is a method which has long been in use. A decade ago, in a paper not
accessible to me at the time I carried out this work, Stahl introduced
the use of anhydrous chloride of cobalt, the rapidity of transpiration
being estimated by its change in color from blue to pink as the salt absorbs
water, because cobalt salts are blue when anhydrous, red when hydrated.
As standards I used pieces of absorbent paper saturated with cobalt-
chloride solution, one set not quite as blue as it would be if entirely anhy-
drous, the other not as red as if entirely hydrated; these sets were
separately sealed in glass vials. While changing from the color of one of
these to that of the other, a piece having an area of 100 square centimeters
absorbed 0.46 gram of water. By the use of this cobalt paper the trans-
piration of pinnae in their natural positions on the tree could be tested, the
evil effects of cutting being entirely obviated. However, the method has
compensating disadvantages.

The cobalt paper must be directly applied to the transpiring surface,
and it must be protected against the possibility of absorbing water from
the atmosphere. This is accomplished by holding it in place with glass
(microscope slides serve the purpose well), the latter in turn being held
by clamps. This method is likely to make the transpiration abnormal
by interfering with the wind, by cutting off some of the illumination, and
by placing a portion of the leaf, at least for a part of the time, in an
abnormally dry atmosphere.

Transpiration is exceedingly sensitive to changes in the illumination,
so much so that if a slide which is locally corroded be used over either
surface, the paper under the etched spot will be noticeably slower to turn
red; therefore clear and perfectly clean glass must be used. However,

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there is no avoiding interference on the part of the cobalt paper itself;
but nearly all of the light to which the plant has access comes from above,
and the disturbing effect of cutting off that from below is correspondingly
moderate.

The wind affects the transpiration in two ways — by constantly changing
the air immediately outside the stomata and by agitating the leaves and
thus causing a circulation within the intercellular spaces and an egress
and ingress through the stomata. The disturbance of the first of these
effects is inoperative in this case because of the drying action of the cobalt
paper ; and as the pinna as a whole remains fairly movable, only the small
part between the slides being rigid, and the intercellular spaces are con-
tinuous, the interference with the circulation is at most but partial. The
disturbance of the transpiration by cutting off the wind is therefore not a
serious matter.

That the cobalt-chloride test of transpiration places the leaf in an
abnormally dry atmosphere is a great and unavoidable objection. Even
if the plant did not react to this condition other than as a surface of water
would, namely, by more rapid evaporation, this error would be very diffi-
cult to control ; for while the blue paper must constantly surround itself
with very dry air, this medium becomes damper as the paper turns red. 21
In practice, the matter is far from being as simple as if we were studying
evaporation from a water surface only. When the cobalt paper is applied
to a surface with open stomata it suddenly makes an increased demand on
the water vapor in the intercellular spaces which are in immediate contact
with the open pores, and most particularly on the water in the guard
cells themselves. An abnormally active escape results, this in turn causes
the stomata to close, checking the loss, and this process presently brings
the transpiration below the normal. Thus, the decreased illumination
and abnormal dryness work together in reducing the transpiration, and
their combined effect is to cause the paper to change color, at first more
rapidly than the normal transpiration would make it do so, but afterwards
much more slowly.

That the rapidity of reddening of the cobalt paper comes far from
indicating the actual rapidity with which the plant loses water is clearly
shown in the last preceding table, in which the time intervals are those
required for the reddening to take place. As the first column shows, the
initial reddening took place in one-fiftieth of the time consumed in the
last interval. The second column shows the relation of the reddening to
the actual, though abnormal, transpiration. The area of this pinna was
75.4 square centimeters. Of this, 19 square centimeters was under the
slide, leaving 5(1.4 square centimeters free; 56.4 centimeters of cobalt
paper would absorb 0.26 gram of water in changing color. Evidently

21 Very soon after paper in contact with actively transpiring leaves is really red,
water begins to precipitate on the glass.

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the cobalt paper withdrew water from the leaf during the first two periods
more rapidly than it transpired from the free surface but much less
rapidly during the last period. The change from an acceleration to a
retardation occurred in about half an hour ; it often appears more quickly.
The measurement of transpiration by weighing cut pinnae and their con-
tainer was deemed unavailable when this experiment showed that the rate
fell during a few hours to 8 per cent of the initial. As determined by
the cobalt test, the rate fell during the same experiment to less than 2 per
cent. This exhausts the really distinct methods of making continuous
direct determinations of the transpiration of a single subject.

Neither of these usually reliable methods being alone available in
working on the coconut, I next had recourse to combinations, attempting
to check a continuous experiment with one method by applying frequent
corrections obtained from observations by the other; thus at the same
time having the advantage of accuracy in the weighing method, and that of
working with uninjured pinna? on the tree by the cobalt test. I first tried
to reach these ends by determining at intervals of several days the loss of
weight of pinnae placed in bottles of water, and at the same time com-
paring the rate at which cobalt paper was turned red by these cut pinnae
with that at which it was altered when it was applied to pinnae in situ on
the tree. My most satisfactory experiments of this kind furnished
material for the following table :

The pinnae A, B, and C were cut on the afternoon of January 17 and the cut
ends killed by insertion in nearly boiling water. The leaf D was freshly cut at
2.30 p. m. January 18, and its ends not killed. All weights are in grams. The
loss was determined regularly at one-hour intervals during the day. The bottles
were hung in the tree, putting the pinnae as nearly as was possible in natural
conditions. The bottles themselves were shaded to prevent heating.

Date.

Hour.

Behavior of cobalt paper.*

Jan. 17

5.30 p.m.

Jan. 18

6.30 a.m.
7.30 a.m.

0.03

0.12
.02

0.02

Red in 8 minutes; leaves were damp, i

8.30a. m.

.14

.09

C and T change equally; not com-
pleted in 60 minutes.

>>9.30a. m.

.10

.08

.09

A and T the same.

10.30 a.m.

.23

.13

.09

B red in 40 minutes; T in 26 minutes.

11.30a.m.
12.30 p.m.

.72
.61

.42
.40

.27

.40

I—

One-third faster on T than on A.

1.30 p.m.

.71

.63

.50

A red in 55 minutes; T in 13 minutes.

2.30 p.m.

.43

.74

.51

A red in 55 minutes; T in 20 minutes.

3.30 p.m.

.53

.50

.35

0.51

D red in 45 minutes; T in 13 minutes.

4.30 p.m.

.39

.86

1.02

1.17

D red in 17 minutes; T in 13 minutes.

5.30 p. m.

.14

.16

.12

.41

D red in 40 minutes; T in 18 minutes.

Jan. 19

6.30 a.m.

.10

.05

.09

.10

(These are totals for 13 hours dark-

ness).

•T=Tree.

bSun strikes A at 10.20, B at 10.25, C about 10.40.

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During the following day the transpiration was much slower and too
abnormal to be worth reporting in detail. The totals for the twenty-four
hours ending January 19 and January 20 were:

Knding-

Jan. 19 :
Jan. 20 !

I B. I C.

4.13 I

4.10
1.71 i

3.55
1.33

2. 02

If now the transpiration of a pinna in situ, be computed from the loss
of weight by pinnae in water, and the relative rapidity with which these
and the former turn cobalt paper red, the following result is obtained :

Hour.

Grams.

Remarks.

7,30 a.m

0.03

Observed for A.

8.30 a.m

.14

Do.

9.30 a.m

.10

Do.

10.30 a.m

.23

Do.

11.30 a.m

.96

4/3 by 0.72.

12.30 p.m

.81

4/3 by 0.61.

1.30 p.m

3.02

4.25 by 0.71.

2.30 p.m

1.19

2.75 by 0.43.

3.30 p.m

1.78

3.5 by 0.51.

4.30 p.m

1.53

17/13 by 1.17

5.30 p.m

.91

2 2/9 by 0. 41

Night _ _

.10

Observed for A.
For one pinna and

Total

one

10.30

day.*

a The tree area of leaves furnishing this figure averaged about 120 square centimeters, the rate
therefore equaling 8.57 grams for 1 square decimeter. Haberlandt (Anatomisch-physiologische
Untersuchungen uber.das tropische Laubblatt, Sitzber. Wiener Akad. (1892) 101, I; 804,807) found a
rate for Cocos at Buitenzorg of 0.89 gram per diem per square decimeter of surface.

Allowing 150 pinnae to the leaf and 25 leaves to the tree, this indicates
a total daily transpiration for the tree of 38,551 grams. My estimates
made in this way have ranged between 28 and 45 liters. These calcula-
tions are based on determinations made on sunny days, and # some of them
are doubtless higher than the average transpiration of the tree for all
days. On the other hand, it is to be observed that no allowance is made
for the fact that not all parts of the pinnae under experiment were free to
transpire.

Another way of combining the cobalt test with the weighing method
is to use fresh leaves at frequent intervals. This combination offers the
advantage that the transpiration of the subjects weighed is never very
much below the normal, but the disadvantage that it is difficult, with such
a frequent change of subjects, to apply a control based on the continuous
use of the same pinna. In practice, if the cobalt paper is always applied
to a fresh part of the pinna, it will turn red once or twice after the pinna
is cut, at practically the same rate as before. Under ideal conditions this
method will furnish really accurate results, but the test of a method is

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its usefulness under unfavorable circumstances, and under them the lack
of continuity becomes too great an objection ; in addition, the observations
demanded at short intervals on several pinnae at once require a dangerous
haste in manipulation. This method is serviceable where immediate
results will answer, as, for example, in testing the effect of shading. Esti-
mates of the total daily transpiration by this method, based on determi-
nations made in the sun, run higher than those just given — sometimes as
high as 75 liters per diem.

After this necessarily prolonged discussion of method, a brief consid-
eration of the relative transpiration from the upper and nether surfaces
of the leaves, the influence of their age on their transpiration, and the
effect exerted from without by the illumination and the wind will be
possible.

Almost the entire transpiration of the coconut is through the stomata
of the nether surface of the leaf. In experimenting on the transpiration
from the upper surface, and at no other time, have I found it necessary
to seal the edges of the glass slides to prevent interference by the moisture
of the atmosphere ; of course, it was also necessary to guard against the
passage of moisture from the nether surface to the upper. These pre-
cautions being taken, it requires at least six hours of continuous sunshine
to enable the cobalt paper to change color. If the leaf is placed in the
shade or in the dark, the hydration is somewhat slower. On January 21,
a day when there were occasional clouds, the average time of reddening,
when the paper was placed against the lower surface, was eleven minutes,
but against the upper, seven hours; this interval, from 9 a. m. to 4 p. m.,
was required for the change; and paper blue at 11.25 was still of the same
color at 5.30, but red at 8.

Experiments were made on the transpiration of leaves which were just
full grown, those about six months older, and those a year beyond matu-
rity. Two series of determinations were undertaken with the individuals
of each age. These varied in detail, as is true with all of this work, but
the relation was constant — the leaves six months beyond maturity trans-
pired rather less than those which had just grown, while those a year old
were decidedly the most active of all. For example, the total transpira-
tion for seven hours, from 9.20 a. m. to 4.20 p. m., February 14, was —

Grams.

Mature leaf 2.70

Six months older 1-68

One year older 3.37

The result for the leaf of mean age is too small ; this is due to its being
the first to become greatly abnormal. The totals for 4| hours, from 1.50
to 5.20 p. m., February 15, were —

Grams.

Mature leaf 0.78

Six months older 75

One year older 1-50

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When I first observed this phenomenon I was surprised that the oldest
leaves showed the most active transpiration, but a few weeks later a paper
by Bergen 22 was received showing that the coconut is not peculiar in this
respect. The figures given above are not corrected for area ; if this were
done it would still further emphasize the difference, because in both cases
the oldest leaves had the least exposed area. The relative activity of cut
pinnae and those in situ was at first exactly the same in all cases and so
demanded no correction, but the oldest leaves were always the last to show
an extreme depression. The transpiration from the upper surface was
slightly more active in the latter, but it was not enough so to account for
any great proportion of the extra quantity. A considerable part of the
total area of the oldest leaves was occupied by small, scattered brqwn
spots, and the leaf was dead two months after these observations. The
tree was a young one.

Thirty or more determinations of the transpiration during the night
have all shown concordant results, the rate being about 1 per cent or even
less of the greatest; during the day; the total transpiration for an entire
night was about one-tenth of that during one hour of sunlight at midday.
Three factors are responsible for this great nocturnal depression — the
darkness, the lower temperature, and the higher relative humidity. The
complete experimental analysis of these three factors was practically
impossible, but the cobalt test, being independent of the moisture of the
environment, is capable of showing the inflence of the illumination inde-
pendently of the relative humidity.

By this test it has repeatedly been proven that a very slight shade will
to a certain extent almost immediately depress the transpiration. Of
course, actual darkness has a very much greater effect. In using the
cobalt test I held the glass slides to the leaf with cork clamps, and there-
fore the spot immediately between these was in approximate darkness.
When, in the first test, the paper reddened in about four minutes, the
change was not appreciably hindered by the cork; but if this first test
required more time, and always during subsequent tests, the darkened
part of the paper was very evidently slower in turning. Beginning at
9.18 a. m. January 21 the intervals required for reddening were ten
minutes and nine minutes ; then, with a light haze over the sun, fifteen
minutes ; all these for the illuminated part of the paper. After the last
determination, the paper was left until the part under the cork was red-
dened; in about forty minutes water was precipitating on the glass over
the lighted leaf, but the darkened paper was still bluish, only becoming as
red as the standard after ninety-five minutes — that is, it took more than
six times as long to change as it did when a mere haze weakened the light.

22 Bergen, J. Y. : Relative Transpiration of Old and New Leaves of the Myrtus
Type, Bot. Gaz. (1904), 38, 446. "The leaves of six out of the eight species
studied transpire more for equal areas when fifteen to eighteen months old than
they do when they have just reached their maximum area (i. e., at three or four
months )."
36540 3

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In observing another leaf, the intervals at the same time were respectively
fourteen and eighty-two minutes, the ratio being practically the same.
The effect of the passing of a cloud before the sun was observed very many
times; it naturally varied with the depth of the shading. In similar
cases the test by weighing shows a depression in transpiration, but I could
detect no additional one to be ascribed to the higher humidity.

It is clearly in large part because the direct sunshine heats the leaf
above the temperature of the surrounding air that the transpiration is so
much more rapid in it than in the brightest diffuse light. The follow-
ing table shows the extent of this overheating. The temperature was
determined by tying a leaf backward around the bulb of a thermometer :

Temperature.

Hour.

In shade.

In sun.

In leaf.

7 a. m.

20.3 21.8

21.9

8 a. m.

24.3

25.2

27.4

9 a. m.

30.7

33.1

10 a. m.

26.9

35.4

11 a. m.

27.8

31.5

» 34. 7

12 m.

28.3

34.7

37.7

1 p. m.

1*31.5

2 p. m.

28.5

31.5

3 p. m.

28.8

36.7

4 p. m.

28.6

30.6

36.4

ft p. m.

27.7

6 p. m.

26.6

27. 6

28. 5

» Light cloud.

b Cloudy.

How great a difference in evaporation, as a merely physical process, these
differences in temperature will exert is shown by a consideration of the variation
in the tension 28 of water vapor with changes of temperature. Thus, at noon the
temperature in the shade was 28.°3; at this point the tension of water vapor is
28.560 millimeters; at the temperature of the exposed leaf, 37. °7, the vapor
tension is 48.463 millimeters; at 11.30 a. m., with a temperature 28.°4, the
relative humidity was 66. The tension of vapor in the air at that time was
18.89 millimeters, making a relative humidity for the temperature of the leaf of
only 39; the unsatisfied possible tension of vapor in the air was 9.69 millimeters
in the shade, while it was 29.583 millimeters for the leaf.

The actually observed excess of transpiration in strong, direct light
over that in the shade was greater, as a rule, than that of evaporation from
a water surface under the same temperature conditions ; the change from
a light haze, under which the leaf is already somewhat overheated, to full
illumination, frequently multiplying the rate of transpiration by four.
This extra effect may in part be due to the action of the stomata, and
must in part be ascribed to the expansion of the gas in the intercellular
spaces, with the consequent ejection, as the leaf is warmed, of a portion

23 Tables of Landolt and Bernthsen.

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of this gas loaded with moisture. Of course, the opposite change in the
volume of this included air would take place as the leaf cools.

It was impossible for me to make observations of any great value on
the influence of the wind, because I could not regulate or measure its
velocity. With a good subject, the concomitant use of the cobalt test
and the weighing method should make it possible accurately to analyse
the wind's influence, showing how much is due to mechanical agitation
and how much to the constant change of the air outside. But no work
on the coconut is sufficiently accurate and reliable for such an analysis.
As was to be expected, the wind made a much greater difference in the
transpiration of the leaves which were exposed to the greatest illumination
than it did in that of the shaded ones. Thus, in one instance, the transpi-
ration in direct sunshine was four times as great in a wind I estimated to
be at 5 miles an hour as it was in a calm; but the increase was usually not
more than 100 per cent. In the shade, a wind of this velocity added less
than 50 per cent to the transpiration. . I was unable to cut off the wind
from a shaded plant without further interference with its illumination.

Any estimate of the total water transpired by entire trees can not be
more than a rough approximation, because, aside from all possible inac-
curacies in the observations on individual pinnae, different days and
seasons are unlike; and different neighboring trees, as well as different
parts of the same individual, interfere with each other's transpiration.
For these reasons any estimate based on observations made entirely in
direct light must be too high. As already stated, some calculations
obtained in this way are as high as 75 liters per diem. In the experiment
from which the estimate of 28 liters was obtained the pinnae were under
as normal conditions as possible, taking their share of shading with the
other pinnae of the tree and being under check by observations on pinnae
in the natural position. The day was bright, but was not quite cloudless,
and not especially warm.

At the rate of 28 liters per diem the annual transpiration is 10,220
liters. In this volume of water the plant takes up the mineral food to
be used in its permanent growth and enough more to cover the annual
loss in the nuts and cast leaves. The amount of mineral food perma-
nently bound up in the growth of the stem and roots can not be very
considerable, and that in the roots which die is already in a place to be
absorbed again. The average dry weight of a fallen leaf may roughly
be put at 3 kilograms, of which 8.5 per cent is ash and nitrogen. Allow-
ing a fall of 16 leaves per annum, the loss of matter taken up in solution
by the roots is 4,080 grams. In each nut the tree loses ash as follows :

Grams.

In the husk 33.84

In the shell 3.36

In the copra 13.83

In the milk 5.97

Total 57.02

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If the tree produces but 20 nuts per annum, which is more than the
recent average at San Ramon, the loss of mineral matter in these is
1,140 grams and the total loss in leaves and nuts 5,220 grams. If this
were absorbed in 10,220 liters of water the concentration would be 0.051
per cent. This is considerably above the average concentration to be
found in ground water, as determined by analyses from water in wells
and springs, but as a general proposition the water in intimate contact
with the ground particles, and, when there is but little water in the soil,
all of it, will be more concentrated than that which will run freely from
wetter ground ; and the valuable mineral food of plants is absorbed from
such dilute solutions in greater proportion than is the water in which it is
dissolved.

Effect of drought.— The season during which I carried on my work at
San Ramon was characterized by extreme dryness, and this condition has
interfered with my study of the plant's normal physiology, but at the
same time it has given me an opportunity to observe the injury done by
the abnormal conditions. The following table contains my measure-
ments of the rainfall for this year and Mr. Haviee's for the corresponding
months a year ago :

Month.

1904-5.

1903-4.

Relative

humidity,

1904-5.

November _

mm.
(15-30)91.5

2.5

12.5

mm.
(1-30) 208

260

431

232

Per cent.
79. 9

79. 2

75. 65

72. 35

75.43

74.9

December _ _ _

January __

February

March

April

The third column gives the average relative humidity at or near the
beach at 11.30 a. m. for November and at noon for the remaining months.
Details as to the rainfall and humidity during my work are presented in
the appendix to this paper. While the .dryness of the air certainly has
some direct effect on the coconut trees — for example, in influencing the
movement of the hinge, without regard to how well the roots may have
been supplied with water — I do not believe that serious damage is ever
done to the tree except by the dryness of the ground. In other words,
trees judiciously irrigated have nothing to fear from' a drought, however
severe.

The cultivated part of the San Ramon farm is well supplied with
ground water, which, as a rule, finds the surface through a number of
large springs. Two months after the drought began, some well-cultivated
spots were still wet from below every morning. During November,
December, and January, I frequently examined the young tips of roots,
and through these months there was no important change in the condi-
tion of the ground and accordingly none in the roots. After the latter

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part of December there was a rapid drying fmck of the streams running
to the farm from the mountains, and the desiccation of the ground became
rather abruptly evident a month later. Through January, surface culti-
vation kept all but the most porous ground in good condition, but after
this time it was practically useless so far as the soil was concerned.
By the middle of March the soil, where it was not sandy and ready to
crumble, was as hard as if baked, and under the thoroughly cultivated
surface it was full of fissures as much as a centimeter in breadth. ' The
hardness was shown by the behavior of main roots nearly 1 centimeter in
diameter, to whose disposition to grow in a straight line the tree owes its
firmness. These, upon entering the cracks, turned almost at right angles
and started to follow them.

In such a soil it is obvious that, in a short time, growth will be
suspended. On March 21, I was unable to find any roots apparently
normally active. -The cessation of growth had been accomplished, or
initiated, by the shortening of the growing region until the hardened
hypodermis had advanced to within the root cap, obliterating the white
absorbing surface. The disappearance of the absorbing region in the
small branch roots, with short caps, was at first less complete, but by
April 11 that portion remaining unlignified at the tip even of these was
more or less flaccid, even in the early morning.

The turgor in the cortex of these roots equals nearly 0.4 normal potassium
nitrate. Approaching the meristem it is higher, probably 0.5 normal. In the
cap and epidermis I was unable to determine it. It will be noticed that the in-
crease in turgor caused by desiccation and cessation of growth is more than half
what it is when the cessation of growth and immersion in 0.5 normal potassium
nitrate act together. This shows what proportion of the increase in the latter
is directly due to the absorption of the salt. 24

Of course, the roots of a tree do not all suffer alike, because different
strata of the soil do not become equally dry. I tested the amount of
moisture in the soil on April 11, at depths of 20, 60, and 100 centimeters,
determining the weight lost by drying at a temperature of 40.3° C, the
dew point being 25.5° C. The loss was —

At depth of — Per cent.

20 centimeters 16.0

60 centimeters 21

100 centimeters 25 23.2

24 For the influence of rather concentrated solutions on the turgor of immersed
roots, see Stange, in Bot. Zeit, 1892. For the influence which the mechanical
prevention of growth exerts upon the turgor, see especially Pfeffer, Ueber Druck-
und Arbeitsleistung, » 1893. For a general treatment of the dependence of the
turgor upon the rate of growth, see my paper, Ueber den Einfluss von Licht
und Temperatur auf den Turgor, loc. cit. 1896.

25 The difference in available water is much greater than these figures Would
indicate, for at 20 centimeters in depth the soil is the hard clay already mentioned,
while at 100 centimeters it is a sandy loam, crumbling readily; at 60 centimeters
it is intermediate in character.

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A very large part of the roots of the coconut grow in the stratum
between 20 and 50 centimeters, and a tree to which water is available
only at a greater depth must suffer. If conditions exist which permit
roots to grow only at a greater depth, the obvious result will be a larger
proportion in this deeper situation; in this way trees growing in dry
places adapt themselves to their environment. However, trees which are
compelled to adapt themselves to unfavorable conditions of any descrip-
tion can not be expected to be prolific. This is well illustrated by the
dearth of nuts on the Co cos-clad hills about Romblon and Masbate. The
water which can be drawn from a dry soil contains a greater proportion
of mineral substances dissolved in it than that which is available when the
soil is wet, so that the proportion between the quantity of available min-
eral food and the amount of water absorbed is not constant.

The shoot suffers from the inactivity of the roots. The influence of
the drought on the growth of the leaves, and on the action of the hinge,
has already been shown. The leaflets, which under these conditions are
more folded, absorb less light, so that the leaf area which the tree has at
its disposition is less efficient in photosynthesis. A normally active tree
produces from twelve to twenty-four or more. leaves a year. After Decem-
ber, during this drought, no new leaves appeared on trees which were
less than 2 years old, and not more than one on any tree less than 5 years
old. As a general rule, the older the tree the later it begins severely to
suffer, the probable cause being that its roots run deeper than do those of
the younger ones ; but the growth of the leaves of individuals of all ages
was very evidently retarded during February. This, in itself, would
result in a decrease in the number of leaves borne at one time; but
another factor is at least equally efficient in bringing about this result.
The old leaves of the coconut are cast in a succession which, in adult
trees, normally keeps pace with the appearance of the young ones, so
that the number present at any one time does not materially vary. The
internal factors causing the fall of the leaves have never been investigated,
but there is no doubt that dryness is one of them. The "physiological
dryness" caused by the outside drought naturally finds expression in a
more rapid aging and falling of the leaves. In fact, the first, and for a
long time the only, noticeable symptom of dryness is the number of leaves
pendant or falling. It has already been noted that trees without a
rather indefinite minimum number (say, twenty) of leaves, have not the
vitality which is necessary to ripen nuts. An individual with only ap-
proximately this number will naturally not bear many. A retardation
in the production of leaves and an acceleration in their loss, when acting
together, will rapidly bring even the strongest trees toward this limit.

The flowering branches are formed in the axils of the leaves, and the
formation of fewer of the latter must in itself ultimately result in the
growth of fewer of the former. However, in practice, the development
of these branches themselves is dependent, like any other growth, on a

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sufficiency of water; it is arrested at the same time as is that of the
younger leaves, long before the ones formed during the drought would
bear flowers on their axillary branches, even in the most favorable
weather. Thus the number of branches whose pistillate flowers were
"opened" on a certain tree during the six months ending with April,
1905, was six, whereas during the preceding six months it had been nine.
The flowers do not open until more than six months after the first appear-
ance of the subtending leaf.

The number of nuts which can be borne depends upon the number of
fruiting branches, and on every branch there are more pistillate flowers
than can possibly give rise to mature nuts. The number which develop
is a matter of individual difference between the trees; some regularly
bear as many as ten, others never more than three. My observation of
mature trees has not shown that the drought exercises any influence on
the number which blast. It has seemed to me that in a grove in which
the trees are in the first year or two of bearing a somewhat larger propor-
tion than usual was blasting during the drought, but then it is also true
that a very large percentage always do blast on such trees (on the first
branches no nuts mature), so that this effect is uncertain. Neither have
I been able positively to determine that the drought exerted any influence
on the rapidity of the ripening of the nuts. If there is such an influence
it will be toward a more rapid ripening, the tree thus producing smaller
nuts, with less store of food. The records of the San Ramon farm show
the number of nuts cut and the number of nuts and amount of copra sold,
but they do not show how many nuts have been picked up from the
ground nor at what times nuts have been used for seed ; and these items
are so considerable that I can draw no sufficiently accurate conclusions
as to the yield of copra per nut. 26

The direct result of the checking of the growth of the young leaves and
flowering branches will be a deficiency in the yield of nuts, beginning not
less than nine months after the drought first makes itself felt (nine
months being about the minimum time between pollination and maturity)
and ending at least eighteen months after the drought is broken (that
being the usual time elapsing between the appearance of a leaf and the
maturing of the subtended nuts).

There are other considerations which make it necessary to extend this
period of depression in both directions. When more than a minimum
number of nuts are borne on a branch the latter itself is unable to sustain
the weight, so that the additional support must be furnished by the
petioles of the lower leaves. The untimely casting or depression of these
leaves withdraws this support and leaves the branches carrying the great-
est load in a condition in which breakage is likely to occur. The nuts

26 Judging by the eye alone^ I can say positively that the nuts cut during April,
1905, averaged distinctly smaller than usual.

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are heaviest about three months before maturity, and the loss by premature
falling becomes considerable within five months after a drought first
becomes serious. At about the same time the drought makes itself felt in
injury to the crop through another channel. At all times some nuts are
destroyed by crows, but the loss is usually inconsiderable. However, in
a period of drought, when other food is scarce and the water courses are
dry, they concentrate their attention on the young coconuts and accom-
plish no little destruction.

The injury to the tree's vitality during a prolonged drought is so severe
that the return of favorable weather conditions is but slowly followed by
the resumption of the normal activity. When rains come, the roots must
awaken from a state of defensive rest in which a prompt response can not
be expected. The partly folded condition of the pinnae, induced by the
dryness, seems permanently to remain; at any rate, recovery from it is
very slow. A tree which through unfavorable conditions has only twenty-
five leaves remaining has not the strength, even under the best conditions,
at once to return to the formation of new leaves at the rate which is neces-
sary for the maintenance of a head of thirty. Recovery after a drought
is a building-up process, and it must be a slow one. It can hardly be
complete in two years, and the return to the normal crop of ripe nuts
which can be produced during uninterrupted good seasons can only be
well under way in this time.

There is no record of the rainfall at San Ramon prior to September,
1903. The beginning of that year was a period of drought, like the
one which has characterized the early months of 1905, but the former
can not have been as intense as the latter, for the springs did not so com-
pletely disappear. The following record of the number of nuts cut shows
how gradually this drought made itself felt and how prolonged its effects
have been. 27

January, 1903 55,160

May, 1903 50,000

August, 1903 45,000

November, 1903 40,723

February, 1904 30,637

May, 1904 , 33,800

August, 1904 .„.. 39,765

November, 1904 30,208

February, 1905 31,972

May, 1905 61,550

The report of the superintendent of the farm for June, 1902, states
that there were at that time 5,7.22 coconut trees in bearing on the farm
and that 1,809 trees should begin to bear within two years from that date.

'■" The nuts are cut every three months. The work is done by contract, at the rate
of 2 pesos per 1,000. This record is made from the "general-expense vouchers"
for the expense of cutting.

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With this increase in the number of trees, without any improvement in
their yields, if there had been no drought, the total cut of nuts for 1904
should have been over 300,000; the actual number was 134,410. The
record just given shows that the period of depression which followed the
former drought was identical in character with the one to be anticipated
from the present condition of the trees. The first real step in return to
a fit yield was the cutting of May, 1905, about two years after the former
drought ended; the return can not go much farther before the effects of
this drought will head it off.

It is then the experience at this farm that a "dry season" occurring
only every other year will constantly keep the yield of nuts at consid-
erably less than half of what it would be if the supply of water were
always sufficient for the tree's needs. It is obvious that a coconut plan-
tation will be a probable source of continual profit only in localities where
dry seasons may never he expected or where it is feasible by irrigation
always to keep the ground sufficiently moist to enable the roots to preserve
their full, normal activity.

CONCLUSION.

We have just seen that a considerable supply of water must constantly
be at the disposal of the coconut, or it will protect itself against injurious
desiccation by a partial suspense of its vitality. The necessity of this
water as the carrier, in solution, of the plant's mineral and nitrogenous
raw food has previously been touched upon. I made no direct experi-
ments in the fertilization of the coconut, but it is the unanimous experi-
ence of those who are acquainted with the subject that an increase in
some of the constituents of its mineral food has a very marked favorable
effect on the production of the fruit. 28 At San Kamon certain trees are
pointed out as particularly productive because they have long received
the waste from the kitchen. The quantity of mineral food which the
tree takes is roughly proportional to the amount of water which it
absorbs. 29 Increasing the plant's transpiration has, then, the same effect

28 Experiments with the object of determining whether the soil surrounding the
coconut roots contains nitrifying organisms were undertaken by Dr. W. B.
Wherry, of this Bureau. Unfortunately Dr. Wherry left Manila before the work
could be completed. Indications of nitrification were not lacking in his work,
which is sufficiently encouraging to be continued. The assistance of nitrifying
organisms would be a material advantage to the coconut, although it has been
shown above that the amount of water which the tree takes up and transpires
would, even in such poor soil as that encountered along the beach, contain a
sufficient quantity of inorganic constituents to allow* the plant to thrive. — P. C. F.

29 It is true that in a wet soil the food is in more dilute solution than in a dry
one, but this is partially compensated for by the selective absorption of nutrient
salts from very dilute solutions, the solution absorbed being more concentrated
than that in the ground. The more dilute the solution the greater is this selective
power.

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as applying a fertilizer to the ground. The amount of transpiration can
be increased in two ways — by increasing the amount of water at the
disposal of the roots and by improving the conditions for its evaporation
from the leaves.

In seasons, of drought the first method does the plant a double service,
for the water which is artificially furnished is not only valuable in itself
but also because of the substances dissolved in it. However, during other
seasons, irrigation may not merely be useless but even very injurious, for
ground too wet does not favor the activity of coconut roots any more than
that which is too dry.

We have seen that the transpiration of the coconut is somewhat accel-
erated by the wind, and greatly so by intense illumination. Therefore,
so long as the roots are not in too dry a soil, it is in the plant's interest
to be exposed as much as is normally possible to these two agents. On
any considerable tract devoted to coconut culture this can be done in but
one way — by not planting the trees too close together. I have never seen
a grove in which the trees were sufficiently far apart so that, unless other
conditions were very unfavorable, the trees around the outside were
not much more productive than those in the interior. At San Ramon,
a considerable proportion of the trees are planted in double rows, one row
along each side of a narrow road. In such a row, which contained no
nonbearing trees, I found the yield at one cutting to average 22 nuts to
the tree. A row of trees along the well-drained bank of a slough yielded
an average of 27 nuts, all trees producing. A single tree standing by
itself in the open yielded 55 nuts. In the interior of an old grove, the
average for the producing trees was about 11, and in the same situation
in a large one on the neighboring hacienda of Talisayan the average for
bearing trees was only 8; the individuals in the area where this count
was made were as a rule about 18 feet apart, their crowns interlaced
freely, producing a rather dense shade, and many trees were without ripe
nuts.

I have no doubt that up to a distance of at least 15 meters any
increase in the intervals between trees will result in an appreciable
advance in the average yield per tree, but by planting beyond the inter-
vals at which the interlacing of roots and of leaves would bring the trees
into keen competition for water and light, and would also largely break
the wind passing through the crowns, the increase in the yield of nuts
for the individual trees would not be commensurate with the area of
land in use. In my opinion, the trees in a grove can usually best be
placed at intervals of about 9 meters. In exposed rows they may well be
closer together, and where intense cultivation is economically possible the
distance between them may be a little less.

The natural habitat of the coconut is the strand. It is restricted to
this because it bears fruit too large to be practically transportable by any

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other natural agent than the water ; and it is adapted thereto by possessing
superficial roots which are uninjured hy temporary exposure to concen-
trated solutions, hy having a tough, very elastic trunk, and hy producing
leaves which are not merely tolerant of the most intense insolation and
wind hut which are unable to work to the best purpose without more light
and wind than many plants can endure. As is true for every cultivated
plant, it is possible to create for the coconut conditions altogether more
favorable for its utmost thrift than are ever known to Qccur in nature.
It naturally grows in a "poor" soil — that is, in one in which its mineral
and nitrogenous raw food is present in very dilute solution. We can
improve its environment in this respect, and can profitably carry this
improvement much further than is the general practice at present. But
the coconut must not be expected to thrive, even in the richest soil and
with the best cultivation, if its supply of light is restricted by other trees
or in any other way, or where the air is too still or an adequate supply of
water is not always available near the surface of the ground.

There is another method of increasing the yield of coconuts, slower but
more permanent than improved cultivation; this is by the selection of
seed. I have done nothing with this subject, and only mention it because
the results of selection can not appear for many years, and a mistaken
method would be long in showing its uselessness. Nuts obviously should
be selected for seed from trees conspicuous for the amount or quality of
their yield. It is usually not a difficult matter to decide whether or not
the tree's superior yield is due to its growing under exceptionally favora-
ble conditions. If it is, it shows how other trees may be made to bear
equally well, but there is no reason for selecting the nuts of such a tree
for seed; its offspring can not be expected to bear more nuts under
ordinary conditions than the parent would have done without its excep-
tional advantages. The environment is not -hereditary. The tree the
nuts of which should be used as seed is the one the production of which is
great in proportion to its opportunity. A tree bearing regularly 12 nuts
to the cutting under conditions which allow its neighbors but 8 should
have its nuts saved for seed in preference to those of an individual having
30 nuts among equally productive neighbors.

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Hygrometer readings, San Ramon farm.
NOVEMBER, 1904.

Date.

Beaeh.

Rain-
fall to 4
p. m.

6 a.m. I 1

>m.

Dry.

4 p. m.

Dry.

Wet.

Relative
humid-
ity.

Dry.

Wet.

Relative
humid-
ity.

Wet.

Relative
humid-
ity.

Per cent.

o
25
23.1

24.9
26.3
26. 2
29.1

28. 5
28.6
24.3
26
28

29. 6

23. 6
22. 9
23.8
24. 6
24.2

26. 4
26. 3
25. 7
23.4

24. 5
24.6
24.1
24.2

Per cent.
89

93-

mm.
'21

3.5
29

7
Trace.
Trace.
Trace.

ir»

23.6 1 23.1

85+

91-

91 —

91-

24.1

25. 5

27.5

29.1

29.8

28.9

28.6

29.7

23.6

23. 5
29. 5
2(5. 6
25. 5
27.3
26. 1
25. 4
25. 7
24.6
23.3

85
88
95
75
82
80
77
72
72
62

17 _

23.9

24. 5

24.2

24.8

24.5

27.9

24. 5

24.6

21.2

22.1
23.7
23.8
23.8
23.2
23.4
25. 4
23.5
21.6
23.4
21.2
20.2

18 _

21 _

27 _

27. 5

2<S . _ ___ „

30 _

27.9

24.8

Average

88.8

79.9

83.3

91.5

Date.

Interior.

6 a. m.

12 m.

4 p. m.

Dry.

Wet.

Relative
humid-
ity.

Dry.

Wet.

Relative
humid-
ity.

Dry.

Wet.

Relative
humid-
ity.

Per cent.

24.5

25. 5

27.5

28.4

23.5

25.9

26.2

27.2

23.3

22.9

23.3

24.2

24.5

25.5

25.2

25.6

22.8

24.5

24.4

23.5

24.5

Per cent.
90+

91-

82
83
80
94
89
85
69
80

23.9

23.5

27.5

24.3

22.5

26.9

24.5

23.9

23.8

21.8

22.5

23.2

23.5

23.4

24.5

23.4

22.6

20.8

20.2

95+

91-

23.2
25.3
24.5

28.5

29.4

28.4

28.3

28.9

28.5

29.4

22.9

23.1

23.5

25.5

25.7

25.4

24. 5

69+

| 26

! 27 ___

27.8

25.2

Average

91.5

81.2

87.6

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Hygrometer reading*, San Ramon farm — Continued.
NOVEMBER, 1904— Continued.

Temperature and humidity.

Averages.

Reach.

Interior,
o

Difference

Temperature:

6 a. m

21.3

23.7

0. 6

12 m

28
26.8

• 27. 5
26

4 p. m . _ .

- .8

Humidity:

Per cent.

6 a. m

88.8

91.5

+2.7
+ 1.3
+4.3

12 m. __

79.9

81.2

4 p. m_ _

83.3

87. e

DECEMBER, 1904.

Date.

Beach.

7.30 a. m.

11.30 a. m.

4 p. m.

Dry.

Wet.

Relative
humid-
ity.

Dry.

Wet.

24.5
24
24

Relative
humid-
ity.

Dry.

Wet.

Relative
humid-
ity.

Per cent.
76

1 __

22.6
25
27. 2
24.3
25.5
27.4
26.4
25.1
25.3
26.9

21.6
22. 3
23.6
22. 7
22. 6
24.1
24.4
23.2
24.1
24.5

Per cent.
92

87
78
76
85
85
91
81

26.4

28.5

Per cent.

66
69

27.9

26. 2

27.6

29.1

27.2

28.3

27.8

27.6

27.3

28.1

28.5

24.6

23.9

23. 5

24. 2

24.5

25.1

24.8

25. 5

25.5

25.3

25.5

4 _. _

5 _

28.8

28.3

28.9

28.5

23.7

24.3

25. 5

25.9

26.3

65+

7_ ___ _ _

8 _

10 _ _

11 _

12 _

26. 2
26.4
26.2
26.8
26.5
25.7

26. 5
25
25.5
24

25. 3
25.9
25.7

25. 6
24.4
26.3
26.7

23.7

24.3

25. 7

24.7

23.9

23.6

24.4

22. 7

23.7

24.2

24.6

24. 3

83
79
85
92
86
86
81
89
91
89
87
83
87
89
80
87
82
80
81
83

27.7

24.8

79
79

13 _

27.7
28.1
29.1

25. 5
26. 1
25.3

84
82
73

29.5

28.9

28. 2
27.5

26. 3
27. 2
27.7
28.5
26.6
26.9

25.6

27.2

25. 5

26.3

24.8

25.9

24.6

24.7

83
84
76

87
80
83
84

19 _

28. 6

28.3

27. 5

27.5

27.1

27.7

25. 3
25. 2
25.4
24.2
25. 5
24.8
24.8

77
78
85
76
82
83
79

20 __ _

85 j
83

27 _

27.4
27.3

25.3
25.1

85
84

26. 8
27.6

25.4
25

89
81

28- _

29 __

25 1 22. 5
26.5 24
26.2 i 24

28.5
27. 2

25. 1

25. 2

28.1

Average

84. 27

79.2

80.52

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Hygrometer readings, San Ramon farm — Continued.
DECEMBER, 1904— Continued.

Date.

Interior.

7.30 a.

11.30 a

4 p. m.

Rain-
fall.

Dry.

22.5

28.3

24.3

25. 5

26.9

25.9

24.9

26.3

Wet.

21.9

22.8

25.2

22. 5

24.4

24.5

24.2

24.5

Relative
humid-
ity.

Dry.

Wet.

Relative
humid-
ity.

Dry.

Wet.

Relative
humid-
ity.

Percent.
95

o
26.5

28.7
28.7

24.6
25.4
25.6

Per cent.

26.4

26. 5

27.2

28.1

27.2

26.8

27.5

27.6

27.9

24.7

23.5

24.2

24.1

23.9

25.1

25.7

25. 4

24.9

Percent.

86
74

78
72

83
86
83
87
82
85
84
78

mm.
Trace.

27.9

28.6

30.6

27.9

25.8

26.1

27.5

72
79

84
82
78
86

Trace.

Trace.
Trace.

1
Trace.

Trace.
Trace.

1
Trace.
Trace.

0.5

11 __

26.1

26.3

26.5

25.4

25.3

26.6

25.8

25.5

23.7

21.8

26. 5

25. 1

24.1

26.8

25.5

27.7

27.1

24.6

23.5

25.6

23.9

24. 2

24.2

24.6

23.3

23.1

24.5

22.9

24.1

24.9

84
83
85
85
83
89
81
87
93
94
88
81
86
91
91
86
83
80
74
83

27.9

25
24.3

79
74

27.6
27.6

27.8

25.4
25

24. 5

84
81
76

27.5
28.3
28.1
27.6
27.5
26.2
27.3
27.4
27.4
26.2
26.5

25. 7

25. 5

24.3

24.8

24.7

24.8

24.4

24.5

82
81
78
87
77
85
82
80
81
86
85

17— _

27.6

28.5
28.4
27.6
27. 5
27.2
27.5

25
25. 6
25. 4
24.2
25. 2
24.2
24.5

81
79

78
76

84
78
78

24_ _ .._

25.

27.2
27.9

25.1
25.3

85
81

26.7
27.6

24.6
24.4

29.6

28.5

25
25.5

27.5

24. 5

7«

Average

79.28

81. 85

2.5

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Hygrometer reading*, San Ramon farm — Continued.
JANUARY, 1905.

Datt«.

Beach.

Relative
humid-
ity.

Per cent.

7.30 a. m.

i Relative
Wet. humid-
! ity.

Dry.

11.30 a.m.

Relative
Wet. i humid-
! ity.

Dry.
o

4 p. in
Wet.

Dry.

Per cent.

Per cent

24.8

27.6

25.7

24.7

25.5

25. 4

26.8

22.9

24.1

24.3

24.2

23.2

24.4

23.7

23.8

22.5

85
87
86
76
81
87
87
86
87
79
97

29.4

28.6
27.5
27. 5

24.2 65
24.5 71
23. 9 74

27. 5

26.6

27.1

27. 5

26. 5

27. 5

26.5

26.3

27.3

24.5

24.8

23.8

24.6

24.4

24. 5

24.5

25.1

78
80
77
83
73
82
84
82
85
86
84

4 _ .

5 _

6 ...

25
23.6

82
69

9 ___

28.3
27.5
28.3
29.7
27.6

24. 6 74

10 _

24.3
25. 1
26
24.9

77
77
74
80

12 _ __

13 ___

29.1
27.6
27.4

28.8

24.6
24.6
24
24

25. 5
25. 8

78
75
67

82
84

27.8

28.8

27. 5
27.2

27. 6
28.5
26.8
27.8
28.9

24. 5

24. 2
24. 5
24.7

25. 3
24.8
24.7

25. 2

25. 3
25. 8
24.8
25.1
25.6

82
74
75
76
75
84
80
85
84
80
85
80
77

17 __ _ _ _

24.4
24.1
25. 1
24.3
25. 4
27.6

21.9
22. 5
23.4
23. 1
23.3
24.8

80
87
87
91
84
80

28. 8

27.5

28.7

28.9

29.4

25.9
25
25. 3
25. 9
25. 1
25. 8

79
82
80
80
73
75

24 -

25.1
26

25.2
24.5
24. 5

23. 5
24.1
23.4
21.8
22. 5

87
85
86
79
85

27 _

28 .

. 22.5

28.2

24.8

84.74

75.65

80. 28

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Hygrometer readings, San Ramon farm — Continued.
JANUARY, 1905— Continued.

Date.

Interior.

7.30 a. m. j 11.30 a

4 p. m.

Rain-
fall.

mm.

Trace.

Dry.

Wet.

Relative
humid-
ity.

Dry.

Wet.

Relative
humid-
ity.

Dry. Wet.

O ] o

Relative
humid-
ity.

Per cent.

1 _

Per cent.

3__

26.9

26.5

27.9

26.5

26.2

25.2

25.5

25.9

24.4
23.9
23.5
24.5
23.7
24.5
23.6'
23.6
24 -2

81
81
81
76
79
87
87
85
87
79
98

29
29

28.2

28.5

24.2

23.6

66
68
69

27.3 24.1

28 24. 7 .
26.5 • '22.fi

77
76
78
84
74
82
83
80
86
87
83

4 ___

25 77

26.5
27.2

24.4
23.6
24.2
24.3

24.8
24.3
24.3
24.7

7___

23.8

8__i

26.6

28.5

27.7

29.4

25.4

24.7

25.7
24.4

72
78
78
74
81

26. 5
27. 5
26.1
26.5
26.9

12 _ —

27. 5 '24 fi

23.1

22.8

29.4
27. 5
27. 5

28.8
28. 5
29

25.4
24. 6
24
23.7
25. 5
26.3

72
79
75

26.5
27.3
27. 3

24. 5

24.1

24. 2

24.3

25. 5

25.1

25.4

25. 2

24.5

25. 2

24.4

24.7

24.3

27.7

22.6
22.9
23. 2
23.3
23.3
24.7

81
88
88
92

87
78

77 !

78
78 n

68 j 27.3

78 j 28
80 '27

20 _ _ _

78
85
86
85
81
80
80
78
78

Trace.

21 __

27.5

27.4

28.5

28.6

28.7

24.6
25

25. 5

25. 6
24.9
25. 4

80
78
79
79
73
75

27.1

27.7

27.5

28.3

24_

24.9
26.4
25.6
24.7
25.6

23. 5
24.4
24
22

22.5

89
85
87
79

25 .

26___

29 __ _

26.3

31 ._ ___

23.7

27.6

24.3

Average

84.13

74.65

80.60

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Hygrometer reading, San Ramon farm — Continued.
FEBRUARY, 1905.

Date.

7.30 a.

Relative
humid-
ity.

Per cent.
87

11.30 a

4 p. m.

Rain-
fall.

mm.

Trace.

Dry.

Wet.

22.7

22.1

22.4

21.4

22.6

22.5

21.7

22.1

20.5

21.8

Dry.

o
27.2

Wet.

Relative
humid-
ity.

Per cent.
84

Dry. j Wet.

O ! O

28.5 25 •

Relative
humid-
ity.

Per cent.
75

24.6

24.8

24.4

23.9

24.4

24.1

23.1

21.5

o
24.9

3 .

27.6
29.3

23. 5

72
71

28. 5 24. 3

71
74

23. 5

6 _

28.6
29

28.7
28.8
27.2
27.8

25
25. 3
25
24.8
23. 5
25.1

75
74
74
72
73
80

28. 5

24.9
24.5
25.4

75
74
75

10_

28.8

24.3

24.5

23.6

24.3

22.6
21

21.8
20.8
21.9
22

85
84
82
90

87
82

28.1

28.3

28.4

24.5

23.7

24.4

23.4

72
75
70
73
66
69

28
28.8
28.3
28.6

24.9
24.2
23.9
24.4
23.7

78
68
69
71
70

14 .

15 _

20_

24.1

22.4

22.6

20.4

22.1

22.1
20.6
20.9
16.3
17.5
20.4

84
85
87
85
75
87

28.1
28.2
27.4
26.8
26.8
28.5

24.5

22.2

24.5

71
74

76
59
68
72

27.8
28.4
28.4
27.5
27.6

23.1

22.6

73
69
69
69
65

21 _ _

22 ___

27.3
27.4

27.8

23. 5
23.2
24

72
70
72

19.8
24.2

16.2
21.2

69
76

27.5

28.6

23.5

24.5

72
71

Average

84.16

72. 35

71.4

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Hygrometer readings, San Ramon farm — Continued.
MARCH, 1905.

7.30 a. m.

11.30 a.

4 p. m.

Rain-
fall.

Date. ;

Dry.

Wet.

Relative
humid-
ity.

Dry.

Wet.

23.5

24.6

Relative
humid-
ity.

Per cent.
70

Dry.

Wet.

Relative
humid-
ity.

Per cent.

22.4

24.3

23.1

20.4

19.5

Per cent.

82
83

28.3
27.8
28.4
28

28.5
27. 5

24.5
25
24.1

mm,

Trace.

3 ._

4 _ . _

23.5

20.6

29.1
29

28. 2

28.7

28.2

28.5

28.6

29.1

28.6

29.8

29.5

29. 5

29.5

29.1

29.3

24.6
24.9

27. 5
26. 9
26.8
27.9
27. 5
27.4

24.3
24.4
23.5
24

23. 5

24. 6

77
81
75
72
71
80

23.6

24.8

23. 2

24. 5

25. 2

25.5

24.7

25.8

26.1

24.5

26.5

26. 2

21.2

21.7

22. 1

23.3

23.5

22. 9

23.8

22. 5

23.4

23.9

22.8

23.3

87
86

78
84
78
85
85
77
84
84
86
85
83
84
80
80
83
78

23.6 68
23.6 63
24.2 69
24.6 i 74
25.5 J 78
26 81
25. 4 75

; 14 _

28.9
28.6
28.7
28

25.5
25. 5
25
25. 4

78
74
81

i 15

: 16

25.8

77
79
SI

; 17

! 18

, 19

26. 3 7fi

29
27.9
28.9
29.2

26.1
25.7
26.1

25. 9

84
80

' 20

26. 4

26. 5
27

26.3
26. 5
25. 9

80
79
82
80
80
7X

21 _ _

22 .

23 __ _ -

24 _

29. 8
28.3

26 4

25 _ _

25.8 1 82
1

26.7

26.2

27.4

23.6

24.6

24.1

78
81
80

29.7

29.6

29.3

29.6

27. 1 HI

29.7

26.5

28 _

26
27
26

75
73

29 _ ___

29.8
29. 8

26.3
'>£ 1

77
76

31_„

26.3 j 77

30 | 26.8

Average

81.96

75. 46

77.30

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Hygrometer readings, San Ranwn farm — Continued.

APRIL, 1905.

Date.
1

7.30 a

i""~

1 Relative
humid-
| My.

11.30 a

4 p. l

31.

Relative
humid-
ity.

Rain-
fall.

Dry.

! O

; 26.4

Wet.

o
24.9

Dry.

Wet.

o
25. 9

Relative
humid-
ity.

Percent.
84

Dry.

Wet.

Percent.

i w

o
28.1

Percent.

mm.
0.5

Trace.

3
Trace.

9
Trace.

3 j

28.8

30.5

30.6

28.8

29.4

30.6

28.9

28.7

26. 2
27.6
25.3
26. 2
25. 9
26
26.4
26. 6
26. 2
26.1
26. 2

81
77
66
70
72
80
79
73
80
80
82

29.3

28.9

30.5

28.6

29.9

29.4

25. 9

25. 5

25. 3

26.9

25.4

26.1

26. 5

24.4

79
72
70
76

75
76
77
73
85
80
87

[27.!
26.9

1 25.6
26.6
26.7
26.9
25
25. 2

24.5
24.1
23.8
24. 5
24.6
25. 1
23.4
23.2
23.6
23.9

81
79

84
84
86
87
85
91
85

11_

12 _

24.7
25. 8

26.1

26. 7

23.8
23.8

29.3

26.4

30.7

26. 2

18 _ _

27. 2
26.5
27. 2
27.7
26.3
26. 8
27. 2
26.6
27.3
26.9
26. 6

24.3

24.1

24.9

24. 2

23.3

24.3

23.9

24.8

24.1

23.7

78
81
83
79
83
73
78
79
81
78
77

29.4

29.8

29.6

30.6

30.7

31.2

30.1

31.1

26.8

25.9

26.2

26.1

27.4

26.3

26.6

75
77
72
74
70
68
73
73
69

28.6

28.8

29.3

29.9

30.4

25.5

26. 2

26.7

25.9

26.6

26.3

26.7

77
79
71
77
64
71
75
71
83

22 _

23___ _

24 _

25 _ _

32.2

27.3

32. 3

27.9

Average

81.875

74.9

75.32

12.5

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ILLUSTRATIONS.

Plate I.

Fig. 1. Transverse section of old root, showing continuously thickened endodermis
and neighboring tissues.

2. Transverse section, 9 centimeters from tip of root, showing young endo-

dermis, "e."

3. Transverse section of root 4.5 millimeters in diameter, 10 centimeters

from tip, the hypodermal shell forming.

4. Transverse section, hypodermal shell of old root.

5. Longitudinal section, cortical parenchyma of young root in 5 per cent

potassium nitrate, showing wrinkled walls.

(All figures magnified 160 diameters.)

Plate II.

Fig. G. Root 8 millimeters in diameter, 1 centimeter from tip, surface view.
(160 diameters.)

7. Same, longitudinal section of epidermis. (160 diameters.)

8. Same, transverse section. (160 diameters.)

9. An old pneumathode. (1.25 diameters.)

10. Longitudinal section of young pneumathode: S = stele, Co .= cortex,
Ca = cap. (2.5 diameters.)
. 11. Detail, area "x" in fig. 10. (20.5 diameters.)

12. Diagram of small pneumathode, showing relation to loose inner cortex

of parent root. (20.5 diameters.)

13. Stellate cells, cortex of pneumathode. (87.5 diameters.)

14. Thickened cortical cells, base of old pneumathode. (87.5 diameters.)

Plate III.

Fig. 15. Transverse section of hinge, chlorophyll-bearing tissue indicated by sti-
pelling. (87.5 diameters.)

16. Diagram of axis of leaf: A = fibro-vascular bundle, B = schlerenchyma

sheath, C = upper epidermis and hypodermis, D = green parenchyma,
E = hinge, F = nether epidermis and hypodermis. (20.5 diameters.)

17. Upper epidermis, transverse section. (160 diameters.)

18. Same, longitudinal section. (160 diameters.)

19. Transverse section of stoma. (160 diameters.)

20. Tangential section, nethermost layer of green parenchyma; contents

indicated only where bordering an intercellular space. (160 diameters.)

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Copeland: On the Water Relations, etc.]

hil. Journ. Sci., Vol. I, No. 1.

Plate I.

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Copeland: On the Water Relations, etc,

[Phil. Jourk. Sci., Vol. I, No. 1.

Plate II.

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Copeland: On the Water Relations, etc.]

[Phil. Jovrn. Sol, Vol. I, No. 1.

Plate III.

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THE COCONUT AND ITS RELATION TO THE PRODUC-
TION OF COCONUT OIL.

By Herbert S. Walker.
{From the Chemical Laboratory, Bureau of Science.)

THE SOIL.

Coconut production from the standpoint of the quality and quantity
of the oil yielded has hitherto not been investigated, and it was decided
to enter into this subject as fully as possible. The first problem which
presented itself was the influence of the soil in which the trees grow on
the yield of nuts, copra, and oil. It had been noticed for a long time that
coconut trees growing near the seashore at San Eamon produced much
more fruit than those standing farther inland, and it had also been stated
that the former trees bear a better quality of nuts than the latter.

To determine how far these facts might be accounted for by a greater
fertility of the soil near the sea, the following analyses were made of a
number of soils in which coconut trees were growing, the samples being
taken at the beach as well as farther inland, and two from Davao, where
coconut trees flourish :

Analyses of San Eamon soils.

Sample.

Fine
earth.

Moisture.

Loss on
ignition.

P 2 ;V

K 2 0. N.

Fine
earth, CI.

Coarse
earth, CI.

60 mesh.
22.5

37.5

45
3.7
2.1
30 mesh.

26.9

37.2
UO mesh.

43.6

85.7

2.65
2.45
1.99
5.11
7.82
7.33
2. 55
2.65

2.52
2.96
2. 32

7.6
24

5.83
3.06
1.68
7.93
5.97
6.03
1.53
1.45

1.35
1.71
2. 29

1.79
6.04

0.08
.07
.07
.33
.08
.08
.10

0.36
.52
.55

.58
.45

.48
.88

0.18
.03
.02
.13
.04
.03
.003
.02

.01

.004

.01

.05
.11

0.012
.018
.009
.018
.004
.006

0.001
.002
.002
.001
.001
.001

A 2

A 3

Bi _ _ _

B 2

B 3

C 3

.11
.11
.07

.08
.24

.18
.62
.65

.40
.21

D 3

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Moisture on samples E and F determined at San Ramon; on all others at the
laboratory, Manila.

Fine earth determined on original samples.

Loss on N, P 2 5 , K 2 determined and percentages calculated to original sample
on soil dried at 100°-105°.

Soils marked "A" were taken at a distance of GO feet from the sea, A t being
the surface, A 2 18 inches, and A 3 3 feet below.

The B soils were taken from 2,800 feet inland, 40 feet above sea level, where
trees were not bearing so well, and at the same depths as the A soils of correspond-
ing numbers.

The C soils were from the same place as those marked "A," but were taken at
a greater depth so as to reach the locality of the deepest roots, G, being from
4 feet and C 3 from 8 feet below the surface.

The D soils were taken from the same place and depths as the C soils.

Soil E was taken at a depth of 3 to 4 feet, G feet distant from a very healthy
5-year-old tree near the sea.

Soil F was taken at a depth of about 3 feet and about 1,800 feet from the sea,
where trees do not bear so well.

Davao soils.

Sample.

Fine
earth.

Mois-
ture.

Loss on
ignition.

p 2 o 5 .

K 2 0.

Cat).

I
II

h0 mesh.
95

91.9

7.60
1.30

5. 42
1.42

0. 16
.11

0.26
.13

0.05
.03

2. 85
2.06

Soil marked "1" was taken at a distance of 50 yards from the Davao River
about 1 mile inland from the sea, where trees were growing well.

Soil marked "II" was taken at the mouth of the Davao River about 50 feet
from the sea. In this location a few young trees were doing fairly well.

Both samples were taken at a depth of about 1 foot.

Chemically, the results of these analyses show very little difference
between the soils near the shore and those farther inland. The latter,
contrary to what would be supposed, were found to be somewhat superior
to the former, although neither could be called extremely fertile. Chlo-
rine was determined in the first six of these samples, with the idea that
this element might play some part in the better growth of trees near the
sea, but the amounts found were so small as to be almost negligible.
From these results it is evident that the inferior quality of the inland
trees can not be explained by the analytical difference in the soils;
neither does the salt from the sea appear to an appreciable extent, even
around those trees which are actually growing on the beach.

However, the superior growth of trees near the sea might well be
accounted for theoretically by the physical characteristics of the soil
alone. For example, the soil marked "E" in the foregoing table is prac-
tically nothing but a very porous sand which, at a depth of 3 feet, is
completely saturated with moisture; while F is a very stiff clay, such as
the Spaniards formerly used for making bricks. While it is true that
the latter contains more total moisture and plant nutriment than the

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former, the amount available to the tree is probably not by any means as
great, owing to the difference in porosity. 1 In view of the large amount
of water necessary to the life of the coconut tree, one would naturally
expect it to grow better in an easily permeable soil rather than in one
from which water and soluble nutriment can only be taken up with
difficulty. The objection has been raised that according to chemical
analyses the soils near the sea do not appear to contain sufficient plant
food to support life of any kind, much less that of a large and heavily
productive tree like the coconut.

From analyses of coconuts made at this Bureau we have found that
nuts from San Ramon contain nitrogen, potash, and phosphoric acid in
approximately the following amounts:

Part.

Nitrogen.

Potash .

Phos-
phoric
acid.

Husk

Grams.
1.609

660

4.683

1.542

Grams.
3. 915

.947

2.475

1.313

Grams.
0.017

.459

1.740

.171

Shell

Meat

Milk

Total

8.494

8.650

2.387

In 1 hectare of land on which about 173 trees are growing and produc-
ing, a total of about 7,000 nuts per annum may be expected. 2 Under
these conditions there is exhausted from the soil by the nuts alone a
total of —

Kilos.

Nitrogen 59.43

Potash G0.55

Phosphoric acid 10.73

In addition to this there is a large weight of material withdrawn by
falling leaves. Each tree on an average will lose annually lfi leaves,
weighing about 3 kilos each, making about 8,300 kilos per year lost by
173 trees. Analysis shows that in this weight of dry leaves there is
approximately —

Kilos.

Nitrogen 31.09

Potash 74.82

Phosphoric acid 24.05

We have then a total annual drain on the soil per hectare of —

Kilos.

Nitrogen 91.12

Potash ! 135.37

Phosphoric acid 41.38

1 See the paper by E. B. Copeland on the character of the roots of the Cocos.

2 This is on the basis of 40 nuts per tree per annum, a very high average for
San Ramon trees.

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fil

Assuming those figures to be approximately eorreet, it would appear at
first glance somewhat of a puzzle to determine how the tree manages to
thrive and take up so much nourishment each year from a soil seemingly
so devoid of fertility as that along the sea at San Ramon. However,
when we consider the total amount of soil available to each tree, the
problem becomes a simple one. The root mass of a coconut draws nutri-
ment from a depth of at least 2 meters below the surface of the ground
and outward on all sides for from 3£ to 6£ meters distance from its base.
It thus comes in contact with an exceedingly large mass of material and
it makes use of all the available nourishment therein.

In 1 hectare, or 10,000 square meters, of land there is available to the
coconut trees planted thereon a total of at least 20,000 cubic meters of soil,
or, if' we allow a specific gravity of about two, 40,000,000 kilos.

From the table of analyses of San Ramon soils, we find that the soils
near the sea average about as follows :

Per cent.

Nitrogen 0.07

Potash 50

Phosphoric acid 07

In 40,000,000 kilos we have—

Kilos.

Nitrogen 28,000

Potash 200,000

Phosphoric acid 28,000

From the amount taken from the soil in each year, even though no
fresh addition were made, we can calculate the number of years required
completely to exhaust this soil of its plant food as follows :

Years.

Nitrogen 307

Potash 1,478

Phosphoric acid 077

These figures are naturally only an approximation, but they show that
even in a comparatively poor ground there exists more than an abundance
of nourishment for the coconut tree, provided the soil itself is sufficiently
porous and well watered. 3

It seems very probable that in San Ramon at least, if not in most plan-
tations along the seacoast, the nutritive material comes not from the soil
in which the trees are actually growing but from an inexhaustible supply
of water, laden with plant food, which is constantly seeping down from
the higher ground toward the ocean. This underground water supply
would account for the flourishing condition of trees in a sandy soil near
the sea, even in times of drought, when individuals farther inland in
higher, less permeable ground would be dying from want of water.

3 See the paper by E. B. Copeland on the transpiration of the coconut and the
amount of water taken up by an individual tree.

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Fertilization and irrigation. — In the case of the less permeable soils,
artificial irrigation during the dry season would seem to be of the utmost
importance, and any addition to the fertility of the land, either in the
form of manure or of a chemical fertilizer, would probably be repaid by
an increased yield of fruit. For soils near the sea, under conditions such
as exist at San Kamon, irrigation is of course unnecessary excepting in
times of extreme drought, and fertilization would be of doubtful advan-
tage, as the trees in such a location seem to be growing under the
best conditions possible without any attention whatsoever. Fertilizing
material in such localities would probably be leached out and carried into
the sea before it could be of much value to the trees.

THE NUT AND ITS OIL PRODUCTION.

The analytical methods used in compiling the accompanying tables
were as follows: The weights, in grams, of husk, nut minus husk, shell,
and milk were determined directly. To avoid loss by evaporation the
meat itself was not weighed but was assumed to be the difference between
the weight of the whole nut (minus the husk) and the combined weights
of shell and milk.

Copra. — The meat from each nut was allowed to dry in the air over night, so
as to assume a fairly constant weight, and was then weighed directly; 25 grams
were then cut into fine pieces and dried to constant weight at 100° C. for the
determination of anhydrous copra, the latter being calculated back to per cent
in the fresh meat. To approximate the amount of commercial copra obtainable,
an addition of about 10 per cent should be made because of the water ordinarily
contained in this product.

Oil. — The anhydrous copra prepared at San Ramon was sealed in glass bottles
and shipped to Manila for analysis, the majority of the oil determinations being
made by Mr. George F. Richmond, of this laboratory. Before this time much
work had been done in devising a method for the rapid and accurate estimation of
oil in copra. It was found to be almost impossible to make a complete extraction
by the ordinary method of cutting fine pieces and extracting with ether in a
Soxhlet cone. Even after the apparatus had been running for forty hours, a
small increase in weight was obtained by extracting for eight hours more. Grind-
ing with sand and then extracting with ether produced some improvement.
Extraction with hot chloroform alone took out a little more oil, but it was
necessary to continue the operation for at least sixteen hours. The method finally
used was as follows:

A 2-gram sample was intimately ground with fine sand in a glass mortar, the
mixture transferred to a Soxhlet cone, the mortar washed two or three times
with fresh sand, and then finally wiped with fat-free cotton. The extraction with
hot chloroform takes three hours.

The chloroform is then distilled and the remaining oil dried to constant weight
at 100° C. Experiment demonstrated that practically all the oil was extracted
in two hours. The chloroform extract made in this way proved to be entirely
soluble in absolute ether. The sand used was prepared from ordinary sea sand
by taking all which went through a 30-mesh and which was retained on a 100-
mesh sieve, heating this product for some time to destroy organic matter and
then afterwards extracting with chloroform.

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Age in reference to quality of the nut. — One of the first and most
important of the problems which presented itself was to determine the
effect of the age and the relative maturity of the nut on the percentage
of its various constituents ; in other words, to find out the most favorable
time for opening a nut to obtain the largest and best yield of copra and
of oil. With this end in view, the following analyses were made of four
series of ten nuts each :

Series I consisted of 10 nuts selected from a pile which had just been
picked from the trees and which were ready to be used for making copra.
These nuts were all fairly ripe, although the husks were still green in
color and full of water.

Series II was made up of 10 nuts from the same pile as Series I, but all
were very ripe. The husks were dry and of a dead-brown color.

Series III represents nuts which had been selected for seed and set out
to sprout about three months before the time of analysis. They each
contained a small embryo or "foot" and had green sprouts protruding to
a height of about 6 inches. The husks had absorbed a large amount of
water while lying on the ground.

Series IV was a rather abnormal lot of nuts which had been set out for
seed similarly to those in Series III, but for some reason the individual
ones had failed to sprout, although they had been standing for six months.
The meat had become somewhat softened and in several cases it was
discolored and possessed a bad odor. To a greater extent than any
other this series shows what large variations may exist among nuts of
the same age.

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64
Series I. — Ten nuta, fresh from trees but fairly ripe (all green husk*).

No.

Average

2, 702
2, 725
3,039
3, 182
2,830
2, 316
2, 872
2,930
2,100
3,787

2,848

Husk.

1,160
1,265
1,510
1,547
1,300
1,106
1,157
1,350
925
1,915

1,323

42.9
46.4
49.7

48.6
45.9
47.8
40.3
46.1
44.0
50.6

46.2

Nut minus
husk.

1,542
1,460
1,529
1,635
1,530
1,210
1,715
1,580
1,175
1 , 872

57.1
53.6
50.3
51.4
54.1
52. 2
59.7
53.9
56.0
49.4

Shell.

290
330
395
340
299
239
338
345
260
395

1, 525

53.8 j 323

10.8
12.1
13.0
10.7
10.6
10.3
11.8
11.8
12.4
10.4

Meat.

725
590
639
585
606
541
652
580
505
717

11.4

26.8
21.7
21.0
18.4
21.4
23.4
22. 7
19.8
24.1
18.9

45. 2
43.9

51.8
32.8
44.5
46.1
43.9
48. 5
53.2
51.7

21.8

46. 5

54.8
56.1
45.2
67.2
55. 5
53.9
56.1
51.5
46.8
48.3

53.5

No.

Average

Copra (anhydrous).

Milk.

67.2
66. 4
69. 3
59.8
63.4
64.9
62.3
63.0
65.3
68.7

65.0

32.8
33.6
30.7
40.2
36.6
35.1
37.7
37.0
34.7
31.3

35. 10. 2

S.c ! •&

12.1
9. 5

11.5
6.0
9.5

10.8

io. q

9.6
12.8
9.8

588

19.5
19.8
16.3
22.3
22.1
18.6
25. 2
22.3
19.5
20.1

20.6

Oil.

Calculated to per cent in
nut free from husk.

18.8
22. 6
25. 8
20.8
19.5
19.8
19.7
21.8
22. 1
21.1

21.2

47.0
40.4
41.8
35.8
39.6
44.7
38.0
36.7
43.0
38.3

40. 5

21. 2
17.7
23.0
11.7
17.7
20.7
16.7
17.8
22. 9
19.8

18.9

31. 2
37.0
32.4
43.4
40.9
35.5
42.3
41.5
34.9
40.6

11.3
11.8
15.9
7.0
11.2
13.4
10.4
11.2
15.0
13.6

12.4

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Series II. — Ten /<«/<*, very ripe (dead-brown hn$kx).
[Selected from pile of several thousand.]

Husk.

9_
10 _

Average

2,616
1,935
2,025
1,681
2,070
2,192
2, 945
1,948 |
2,049 |
1,735 !

665
350
460
332
480
647
460
437
500
425

Nut minus
husk.

1,951
1,585
1,565
1,349
1,590
1,545
2,485
1,511
1,549
1,310

2, 120

476 22.6 1,644

74.6
81.9
77.3
80.3
76.8
70.5
84.4
77.6
75.6
75.5

77.5

Shell.

Meat.

262
283
320

309
260

13.5
17.0
13.0
16.8
15. 5
17.4
14.6
17.0
15.1
15.0

326 I 15.1

774

602
644
596
585
715
980
641
675
590

ft-

29. 6

43. 5

31.1

59.9

32. 5

50.9

35.5

51.5

28.2

51.6

32.6

56.3

33.3

42.4

32.9

56.9

32.9

51.7

34.0

54.4

56. 5
40.1
49.1
48.5
48.4
43.7

57. 6
43.1
48.3
45.6

680 32.3 j 52.0 48.0

Copra (anhydrous).

4____

6_
7_
8_
9_
10 _

337
360
328
307
302
402
415
365
349
321

Average j 349

54.0
66.4
61.7
62.2
59.6
58.9
58.1
66.3
63.3
63.1

46.0
33.6
38.3
37.8
40.4
41.1
41.9
33.7
36.7
36.9

61.4

38.6

-m 3

Milk.

12.9
18.6
16.2
18.3
14.6
18.3
14.1
18.7
17.0
18.5

825
655
659
j 470
| 685
' 450
|» 1,075
[ 540
; 565
! 460

16.7

638

Oil.

. 5 182

1. 8 239

31,

33.

31.8 | 202

28.

33.

20.

36.

27.

29.7

7.0
12.3
10.0
11.4

8.7
10.8

8.2
12.4
10.8
11.7

10.3

Calculated to per cent in
nut free from husk.

18.0
20.7
16.7
21.0
20.1
24.6
17.3
21.8
19.9
19.9

20.0

39.7
38.0
41.2
44.2
36.8
46.3
39.4
42.4
43.6
45.0

41.7

17.3
22. 7
21.0
22.8
19.0
26.0
16.7
24.2
22.5
24.5

21.7

42.3
41.3
42.1
34.8
43.1
29.1
43.3
35.8
36.5
35.1

9.3
15.1
12.9
14.2
11.3
15.3

9.7
16.0
14.3
15.5

13.4

a Milk very turbid.

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Series III. — Nuts stored three months, just beginning to sprout.

No.

4__

Average __

'53
o

6
>,

Husk.

Nut minus
husk.

be o
1 £

Shell.

bo o

£ Ph

Meat.

c .

0) f-,

<u is
p-

G .
« S

2, 935

1,313

44.7

1,622

55.3

326

11.1

711

24.2

57.2

42.8

2,133

1,060

49.7

1,073

50.3

232

10.9

553

25.9

50.7

49.3

1,966

729

37.1

1,237

62.9

275

14.0

557

28.3

55.7

44.3

1,666

565

33.9

1,101

66.1

242

14.5

509

30.6

52.8

47.2

2,791

1,653

59.2

1,138

40.8

232

8.3

561

20.1

49.9

50.1

2,537

1,395

55.0

1,142

45.0

285

11.2

505

19.9

52.8

47.2

2,664

973

36.5

1,691

63.5

299

11.2

752

28. 2

49.9

50.1

3,993

2,731

68.4

1,262

31.6

281

7.0

536

13.4

51.5

48.5

5,062

3,115

61.5

1,947

38.5

398

7.9

849

16.8

40.3

59.7

2,300

1,160

50.4

1,140

49.6

273

11.9

540

23.5

51.7

48.3

2,805

1,469

49.6

1,335

50.4

284

10.8

607

23.1

51.3

48.7

No.

Copra (anhydrous).

0) g

Milk.

Oil.

Calculated to per cent in
nut free from husk.

Average.

62.4
59.5
63.8
63.6
65.1
58.7
60.0
60.6
62.2
62.1

37.6
40.5
36.2
36.4
34.9
41.3
40.0
39.4
37.8
37.9

13.9
13.1
15.8
16.1
10.0
10.5
14.1
6.9
6.8
12.1

19.4
12.3
19.8
20.4
11.6
13.7
22.2
11.0
13.5
13.8

8.7
7.8
10.1
10.3
6.5
6.2
8.4
4.2
4.2
7.5

20.1
21.6
22.2
22.0
20.4
25.0
17.7
22.2
20.4
24.0

51.5
44.9
46.2
49.3
44.2
44.5
42.5
43.6
47.4

25. 1
26.1
25.2
24.4
24.6
23.3
22.2
21.9
17.6
24.5

35.2
24.5
31.5
30.9
28.6
30.4
34.9
34.9
35.2
27.8

15.7
15.5
16.0
15.5
16.0
13.7
13.3
13.3
10.9
15.2

309

61.8

11.9

427

15.8

7.4

21.6

45.8

23.5

31.4

14.5

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Series IV. — Xuts stored six months which had not sprouted.
[Most nuts of this age have sprouts 20 to 30 centimeters long.]

No.

I H

Average

2,908
2, 541
3,419
3, 154
2,023
2, 276
3, IK)
2, 403
3, 238
3, 585

Grams.
6

Husk.

* _|_

1,272
1,382
1,743
1,462
1,123
1,228
1,939
1,443
-1,800
2, 225

43.7
54.4
51.0
46.3
55.5
54.0
62. 2
60.1
55. 6
62.1

. 2,866 1,562 54.5

I ; I

Nut minus
husk.

1, 636
1,159
1,676
1,692

900
1,048
1,176

960
1,438
1,360

1,305

56.3
45.6
49.0
53.7
44.5
46.0
37.8
39.9
44.4
37.9

45. 5

Shell.

259

12.6
7.8
10.5

8.8
12.5
7.0
8.4
7.5
8.1
7.6

9.1

683
492
666
800
500
478
536
453
696
638

Meat.

594

23. 5
19.3
19.5
25. 4
24.7
21.0
17.2
18.8
21.5
17.8

20.9

51.3
33.0
44.1
51.3
54.7
33.2
37.3
29. 3
34.9
38.2

40.7

48.7
67.0
55. 9
48.7
45.3
66.8
62.7
70.7
65. 1
61.8

59. 3

Copra (anhydrous).

No.

Average.

350
170
294
410
274
136
200
132
242
244

61.4
67.7
69.0
68.4
74.4
56.3
66.2
74.1
63.4
58.5

65.1

38.6
32.3
31.0
31.6
25.6
43.7
33.8
25. 9
36.6
41.5

34.1

12.1

6.7
8.6
13.0
13.5
6.0
6.4
5.5
7.5
6.8

;.6

Milk.

20.1
18.5
19.0
19.5
7.1
18.0
12.2
13.6
14.8
12.5

Oil.

Calculated to per cent in
nut free from husk.

7.4
4.5
5.9
9.9
10.1
3.4
4.2
4.1
4.7
4.0

22.5
17.0
21.5
16.4
28.0
15.3
22.1
18.7
18.2
20.0

41.6
42.5
39.7
47.3
55.6
45.6
45.6
47.2
48.4
46.9

21.4
14.7
17.5
24.2
38.3
13.0
17.0
13.8
16.8
17.9

46. 19. 5

35.5
40.5
38.8
36.3
15.9
39.1
32.3
34.1
33.4
33.1

34.0

13.1
9.9
12.1
16.6
22.7
7.3
11.3
10.2
10.7
10.5

12.4

The variation among individual nuts in the foregoing analyses was rather
greater than had been expected, and it is doubtful if even an average of ten nuts
gives more than an approximation of their true value at a given age.

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However, considering the average percentages as calculated to the nut
free from husk, there appears a gradual increase in the proportion of
meat, copra, and oil from Series T to Series III, with a corresponding
decrease in the percentage of milk, indicating that the meat is becoming
firmer, is losing some water and gaining oil, as the nut increases in age.
In Series IV, those nuts which had been kept for six months, the meat
remains practically the same in amount, but there is a marked drop in
the proportion of copra and oil, probably due to decomposition or other
changes which are beginning to take place in the meat. However, No. 5
of this series, a nut in which decomposition had already set in, shows
an abnormally high percentage of both copra and oil, a fact which is very
hard to account for, although it is possible that this individual may have
been still higher in these substances before decomposition began. In
both Series I and IV the percentage of oil in the anhydrous copra is
considerably higher than it is in II and III, though this is more than
counterbalanced by a much lower proportion of copra in the meat. Both
in very fresh and in overripe nuts there is a considerable deficiency in
oil, but the principal loss is in the amount of copra to be obtained, this
result being due to a higher percentage of water as compared with solid
matter in the meat. In all these nuts it will be noticed that the propor-
tion of shell to the whole nut varies but little.

Analyses of nuts from the same trees but of varying degrees of ripe-
ness. — In order as much as possible to eliminate the variations in the
individual nuts, and to discover if those taken from the. same tree would
not show greater uniformity in their composition, fifty nuts from one tree
near San Kamon were procured for analysis.

Ten of the least ripe among these were analyzed as shown in Series V. All of
the individuals of this series were well developed externally, but were full of.,
milk, and not yet sufficiently mature to be picked for making copra.

The ten ripest nuts of the lot were next selected (Series VII). Their husks
were of a dead-brown color and thoroughly dry.

The remaining thirty were in a condition which might be termed "fairly ripe" —
that is, they were of the kind ordinarily used for making copra. Nine of these
were analyzed at once (Series VI), and the remainder shipped to Manila for
storage and future analysis. In Series V, VI, and VII "total solids" in the
milk were determined in addition to the regular analysis.

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Series V. — Ten nuts nut fully vij>e, fresh front tree.

Husk.

Nut minus
husk.

Shell.

eat.

Copra (an-
hydrous).

A '

<U i +J

a . ; c .

*: +-» c

! C I ■*>

a> as ' a> t?

^ , j=: i a)

: o \ A

v-i

-5 : .£ < °
o j £ | aS

.fie

'S3

\ O ! bC

'53

u o

H : £ 1 5U

&■

' ft i £

ft | ft

f£

4,227 2,995 ! 70.9

1,232

29. 1

232 5.5 ! 410

9.7

33.2

66. 8

136 !

4,018 2,770 69.0

1,248

31.0

240 ; 6.0 i 428

10. 6

34.3

65. 7

147

6(i. 9

4,012 ! 2,882

71.9

1,130

28.1

220 i 5.5 i 378

9.4

30.0

70.0

114

63. 9

4_ .

4,535 ! 3,380
3,737 ! 2.655

74. 5
71.0
70.9
72.7
68.1
69.4

1,155
1,082
1,144
1,069
1,267
1,240

25. 5
29.0
29.1
27.3
31.9
30.6

21
20
21
21
24
23

» 1 4.8 394
> 5.5 ! 362

8.7
9.7
10.6
8.9
10.6
11.1

27.7 72.3
26.0 74.0
33.2 66.8

29.8 70.2
37.2 62.8
37.5 62.5

109
94
139
103
156
152

64.5
56.
62.

64. 6

m. 9

65. 8

3,931
3,919

2,787
2, 850
2,700
2,806

4 1 5.5

2 5.4
4 6.1
J 5.9

418
347
419
450

3,967
4,046

Average _

3,187 ! 1,965

61.7

1 . 222

38.3

I) ! 7.5

445

14.0

48.2 j 51.8

214

69. 9

3,958 2,779

70.0 1,1

79 ! 30.0 j 22

__!_ 1 ...

llr

7 : 5.8 405
Oil.

10.3
Cal

33.7
dilate

66.3

136

64. 5

Copra (an-

d to per cent in

hydrous).

mt free fron

l husk

cc u

No.

ft
ft

ft
O

«3 £

£ C

<x>

r£

<x>

C/2

3.2
3.7

6.0

94.0

590
580

13.9
14.4

18.8
19.2

33.3
34.3

11.0

11.8

47.9
46. 5

7.9

33.1

5.9 i 94.1

2.4

3-_

36.1
35. 5

2.8
2.4

6.5 93.5
6.5 ! 93.5

532

542

13.2
12.0

73
70

1.8
1.6

19. 5
19.0

33.4
34.1

10.1
9.4

47.1
46.9

6.4
6.1

44.0
38.0
35. 4
33.1
34.2
30.1

2.5
3.5
2.6
3.9

6. 7 93. 3

515
512
510
604
551
537

13.8
13.0
13.0
15. 2
13.6
16.8

53
86
67
104
100
150

1.4
2.2
1.7
2.6
2.5
4.7

18.9
18.7
19.8
19.3
19. 3
19.6

33.5
36. 5
32.6
33.1
36.3
36.4

8.7
12.2

9.6
12.3
12.3
17.5

47.6
44.8
47.7
47.6
44.4
44.

4.9

7.5
6.2
8.1
8.1
12.2

7.5

6.0
6.6
6.7

94.0
94.4
93.3

9 _

3.8 6.0 94.0
6.7 j 5.6 ; 94.4

Average _

35. 5

3.5 : 6.3 93.7

| 1

547

13.9

2.3

19.2

34.4

11.5

46.4

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Series VI. — Nine nuts from same tree as Series V, but fairly ripe.

No.

l»_

2«_

3»».
4^_
5«_
6<=_
7«_

Average _

1,644
1,670
2,300
2,164
2,519
1,948
3,467
2,512
3,230

2, 384

Husk.

602
650
1,115
1,075
1,294
992
2,262
1,440
1,985

1,268

36.6
38.9
48.4
49.7
51.4
50.9
65.2
57.3
61.4

51.1

Nut minus
husk.

Shell.

1,042
1,020
1,185
1,089
1,225
956
1,205
1,072
1, 245

1,116

63.4
61.1
51.6
50.3
48.6
49.1
34.8
42.7
38.6

48.9

12.6
12.0
10.0
10.0
9.1
9.6
6.7
7.9
7.1

9.4

Meat.

Copra (an-
hydrous).

28.0
27.3
22.0
21.4
19.9
20.5
13.7
17.9
14.6

50.7
54.6
51.8
50.5
49.5
53.6
45. 5
50.4
44.3

20.6

50.1

49.3
45.4

48.2
49.5
50.5
46.4
54.5

49. 6

55. 7

49.9

63.8
62.7
64.3
64.1
64.1

65. 8

66. 9
64.9
65. 7

No.

8 t

Average

Copra (an-
hydrous).

36.2
37.3
35.7
35.9
35.9
34.2
33.1
35. 1
34.3

35.!

14.2
14.9
11.4
10.8
9.8
11.0
6.2
9.0
6.4

Milk.

375
364
450
407
493
370
500
425
545

10.4

22.8
21.8
19.6
18.8
19.6
19.0
14.4
16.9
16.9

18.9

4.4
4.1
5.0
4.9
5.7
5.2
5.6
5.8
6.0

d 95.6
^95.9
95.0
95.1
94.3
94.8
94.4
94.2
94.0

94.8

Oil.

150

9.0
9.3
7.3
7.0
6.3
7.3
4.1
5.9
4.2

6.7

Calculated to per cent in
nut free from husk.

19.9
19.7
19.3
19.9
18.9
19.5
19.3
18.4
18.4

19.3

44.1
44.6
42.7
42.7
40.9
41.8
39.2
42.0
37.8

41.7

22.4
24.3
22. 1
21.5
20.3
22.5
17.8
21.2
16.7

21.0

36.0
35.7
38.0
37.4
40.2
38.7
41.5
39.6
43.8

14.3
15.3
14.2
13.8
13.0
14.8
11.9
13.7
11.0

39.0 I 13.6

a "Dead ripe."

"Ripe."

"Fairly ripe."

d Oil separated.

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Series VII. — Xutx from Minn' tree (in Series V, hut dead ripe.

1 HUSk - N "lUHk." W Sh0 "'

! i

Meat.

Copra (an-
hydrous).

No.

i ^

S k'

C 1 **

B i +*

*■* B

£ 4=

a> ' .£

A 1 o

«->,_•

c
H

1,624

a be

<y he

be w

0>
Oh

P< ; £
66.4 217

a>
Oh

13.4

'53

545

33.6

1,079

462

28.4

51.9

48.1

240

63.9

1,493
1 , 427

486 32.6 1.007

67. 4 202

13.5
13.0

450
415

30.1
29.1

55.1
58.6

44.9
41.4

248
243

66.0
66. (J

547

38.3 i 880

61.7

185

1,495

445

29.8 | 1,050

70.2

187

12. 5

438

29.3

45. 3

54.7

198

65. 3

1,568
1,437

528
472

33.7 1.040

66.3
67.2

202
198

12.9
13.8

441
437

28.1
30.4

53.5

5(5.7

46. 5
43.3

236

248

64. 2
67.1

32.8

965

1,716
1,564
1,452
1,806

631
489
450
612

36.8
31.3
31.0
33.9

1,085
1,075
1,002
1.194

63.2
68.7
69.0
66.1

202
206
188
219

11.8
13.1
13.0
12.1

476

483
436
496

27.7
30.9
30.0
27.5

51. 8
53.3
53. 5
53.6

48.2
46.7
46. 5
46.4

246
261
233
266

67. 5
65.
65. 6
68.3

Average _

1,558

520

33.4

1,038

66. 6

201

12.9

453

29.1

53.3

46.7

242

66.0

Copra (an-

Mil lr

Oil.

Calculated to per cent in

No.

hydrous).

nut free from husk

t-H
ft

o .

CJ-t-5

«3

*«

<x>

g c

2
ft

•£P

"q3

36. 1

14.8

400

24.6

4.5

95.5

153

9.4

20.1

42.8

22.2

37.1

14.2

34.0

16.6

355

23.8

4.3

95.7

164

11.0

20.0

44.7

24.7

35.3

16.3

33.4

17.1

280

19.6

5.0

95.0

162

11.3

21.0

47.2

27.6

31.8

18.4

34.7

13.3

425

28.4

4.3

95.7

129

8.6

17.8

41.7

18.9

40.5

12.3

5 _ -

35.8
32.9
32.5

15.1
17.2
14.4

397
330
407

25.3
23.0
23.7

4.1
4.5
4.0

95.9
95.5
96.0

152
166
166

9.7
11.6

19.4
20.5

42.4
45.3
43.9

22.7
25.7
22.7

38.2
34.2
37.5

14.6
17.3
15.3

9.7 18.6

35.0

16.7

386

24.7

4.3

95.7

170

10.9 19.2

44.9

24.3

35.9

15.8

34.4
31.7

16.1
14.7

378
479

26.0
26.5

4.6
4.3

95.4
95.7

153

182

10.5
10.1

18.8
18.3

43.5
41.6

23.3
22.3

37.7
40.1

15.3
15.2

Average _

34.0

15.6

384

24.6

4.4

95.6

160

10.3

19.4

43.8

23.4

36.8

15.5

While there is still some individual variation among nuts from the
same tree, these last analyses very conclusively show the change which
is taking place as the fruit becomes riper. The average percentages of
copra and oil, for example, in the nut free from husk in the green fruit,
are only 11.5 and 7.5, respectively, but they rise to 21 and 13.6 in the
"fairly ripe" nuts, and assume a maximum of 23.4 and 15.5 in the case
of the series which had been allowed completely to ripen while still on
the tree. This gain is partially due to an increase in the percentage of
meat, which runs 34.4, 41.7, and 43.6 in Series V, VI, and VII, respec-
tively, at the expense of milk, which falls from 46.4 to 39 and finally to
36.8, but it is also largely accounted for by the increase of solid matter
and loss of water in the former. The percentage of anhydrous copra in

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the meat of the green fruit is XlSt '; it rises to 50.1 in that of the "fairly
ripe" nuts and increases to 53. 3 in those marked "dead ripe/' Tin*
"Fairly ripe" nuts which' had been sent to Manila showed 51.1 per cent of
anhydrous copra in the meat after standing during one month, and, after
two, 53. 9 per cent, this last figure being very nearly the same as that
obtained from the "dead-ripe" nuts taken directly from the tree. The
amount of oil obtainable from this copra also seems slightly to increase
with age, running G4.5, G4.7, and 06 in the three series (V, VI, and VII),
and in those nuts which had stood for one and two months it was found
to be (57.09 and 67.11, respectively. However, it is also quite possible
that these changes of oil content in the copra in greater part are due to
individual variation in the nuts themselves.

Another interesting fact brought out by these analyses is the gradual
decrease of the amount of the total solids in the milk as a nut grows riper.
In green nuts this quantity averaged G.3 per cent and the milk has a
sweet, pleasant taste and is saturated with a gas which I have proven to
be carbon dioxide. The occurrence of an alcoholic fermentation in the
center of a sound, growing fruit, with absolutely no access of air to the
milk inside, is practically impossible, and, besides, analytical tests have
proven the absence of alcohol in the fresh milk, so that probably the
carbon dioxide is a by-product of a process, possibly due to enzymes, which
is constantly changing sugar and water into fat and cellulose. The milk
from the nuts called "fairly ripe" was not so pleasant to the taste, con-
tained very little, if any, carbon dioxide, and had decreased in total solids
• to 5.2 per cent; while the "dead-ripe" samples produced a milk which was
rather insipid, which contained no gas, and which ir* most cases had a few
drops of clear oil floating on the surface; the total solids in the latter had
been further reduced to 4.4 per cent.

Changes taking place during the ripening of a coconut. — From the
foregoing data, and from observations made on very young nuts, the
following are probably the changes which a young coconut undergoes
before it reaches maturity :

When the young fruit first appears it consists of a white, astringent
tasting, semifibrous mass, which afterwards is destined to form the husk ;
and of a thin, green outer skin. The nut gradually increases in size, with
very little change in composition, until it has grown to be about 3 inches
in diameter. Jt then has a comparatively small, hollow space in the
center which is completely filled with a watery fluid of an astringent,
slightly acid taste, and which is much like the juice from a green husk.
As this period begins, a rudimentary shell is formed around the inner
surface of the nut; at first this is very thin and soft, hut slowly it becomes
thicker and harder. Not until the nut has reached its maximum size,
with its shell completed, is there any indication oi meat or of oily
material. When the shell has been formed the milk changes in character,

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it Incomes rather sweet, and a slimy, gelatinous mass, having a sweetish
taste ami containing comparatively little oil begins lo deposit on the
inside of the former. At first this forms cliielly on the lower half of the
nut, hut finally it covers the whole inner surface. This pulpy mass soon
grows thicker and denser, it increases in oil content at the expense of
sugar in the milk, until it assulfl^^he well-known characteristics of
ordinary coconut meat. During this last stage the evolution of carbon
dioxide which previously was mentioned occurs. Even in ripe nuts, after
they have been picked from the tree, there seems to be a slight continua-
tion of the hardening process in the meat, covering a period of from two
fo three months, or until the sprout makes its appearance. Then other
changes occur, the reverse of those which had taken place previously ; the
nourishment concentrated and stored up as fat is now transformed into
sugars and other bodies capable of being directly assimilated hy the young
plant. As this process goes on the embryo or "foot" gradually increases
in size until it occupies tlie whole space inside the nut and makes use of
all the nourishment contained therein for the growth of the young tree.

Therefore, for the largest yield of copra and oil, only thoroughly ripe
nuts (the husks of which have begun to turn brown) should be used, and
it is often advisable to allow the latter to stand in a dry place for a few
weeks before they are opened. The greatest care should be taken to avoid
using green nuts, as it is shown by the tables given above that a loss of
almost 50 per cent may thus result.

On the other hand, coconuts should not be stored too long, for in about
three months the embryo begins to grow, and, even before that time, 'those
nuts which may have been cracked or bruised in gathering, have a
tendency to become rancid.

Analysis of nuts of different color. — In a certain portion of San
Ramon farm there exist, growing side by side in the same kind of soil,
two apparently different varieties of coconut trees, one of which uni-
formly produces nuts of a golden-yellow color, while the other bears a
light-green fruit. Both varieties eventually turn brown at maturity.
Analyses of these nuts are given in the accompanying tables, Series VIII
being ten ripe nuts from a tree which bears a green fruit, while Series IX
is made up of nuts from a tree about 50 feet away whose product is
yellow until it becomes "dead ripe."

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Series VIII. — Ten thoroughly ripe nut* from one tree.

[The nuts on this tree all have a green husk until they become "dead ripe," when they change

to a dull brown.]

1_
2_
3_
4_
5_
6_
7_
8.
9_
10 _

Average .

1,490
2, 100
1,632
1,482
1,862
1,517
1,702
1,623
1,900
1,673

1,704

Husk.

Nut minus
husk.

Shell.

58ft
640
657
437
665
395
567
520
700
475

39.3
29. 6
40.3
29. 5
35.7
26.
33.3
32.0
36.8
28.4

33.1

(50.7
70.4
59.7
70.5
64.3
74.0
66. 7
68.0
(53.2
71.6

204

275
227
235
265
255
260
265
270
210

13.7
12.4
13.9
15.9
14.2
16.8
15.3
16.4
14.2
12.6

14.6

Meat.

397
(563

428
438
482
467
498
476
505
521

26. (5
30.7
26.2
29. 5
25. 9
30.8
29. 2
29.3
26. 6
31.1

28.6

44. 6
52. 6
46. 3
44.4
44.4
53. 5
46. 8
51.3
44.6
57.

;* i

55. 4
47.4
53.7
55. 6
55. 7
46. 5
53.2
48. 6
55. 3
43.0

48. 5

51.5

Average

Copra (anhydrous).

64.2
62.5
62.7
62.6
60.8
65.0
67.0
64.3
65.9
64.6

64.0

35. 8
37.5
37.3
37.4
39.2
35.0
33.0
35.7
34.1
35.4

36.0

11.9
16. 1
12.1
13.1
11.5
16.5
13.7
14.9
11.9
17.7

13.!

Milk.

20.4
26.9
19. 6
25.1
24.2
25.7
22.2
22.3
22.4
27.9

23.7

Oil.

7.6
10.1
7.6
8.2
7.0
10.7
9.2
9.6
7.8
11.5

8.S

Calculated to per cent in
nut free from husk.

22. 5
18.1
23.3
22. 5
22.1
22. 7
22. 9
24.0
22. 5
17.5

21.8

43.9
43.6
43.9
41.9
40.3
41.6
43.9
43.2
42.1
43. 5

42.8

19.6
23.0
16.1
18.7
17.9
22.3
20.5
22.0
18.8
24.8

20.4

33.6
38.3
32.8
35.6
37.6
34.8
33.2
32. 8
35.4
39.0

35.3

12.6
14.3
12.7
11.7
10.9
14.5
13.8
14.1
12.4
16.0

13.3

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Series IX. — Ten thoroughly ripe ants from one tree.
[Those nuts have a golden-yellow eolor until dead ripe, when they look like those of Series VIII.]

No.

Average ___

No.

9_
10 _

1,702

Husk.

428
520
375
353
335
560
510
380
497
486

444

26.5
20.7
22.6
22.0
20.3
35.5
28.7
23.0
31.1
25.2

26.2

Nut minus
husk.

1,185
1,440
1,282
1,255
1,318
1,017
1,270
1,270
1,100
1,440

1,258

73.5
73.3
77.3
78.0
79.7
64.5
71.3
77.0
68.9
74.8

73.8

Shell.

230
256
240
235
245
205
252
247
225
257

14.3
13.0
14.5
14.5
14.8
13.0
14.2
15.0
14.2
13.4

14.1

Meat.

495
589
547
545
568
432
533
538
495
591

533

30.7
30.0
33.0
33.9
34.4
27.4
29.9
32.6
30.9
30.7

31.3

s l

47.1
53.6
53.4
52.7
53.1
49.6
53. 6
51.2
43.4
51.2

50.9

52.9
46. 4
46. 6
49.3
46.9
51.3
46.4
48.8
56. 6
48.8

49.1

Copra (anhydrous).

•§§•§

14.5
16.1
17.6
17.8
18.2
13.6
16.0
16.7
13.5
15.7

Average ____ 272 16.0 485 28.4 174 10.2 19.1

Milk.

28.5
30.3
29.8
29.6
30.5
24.1
27.2
29.4
23.8
30.7

Oil.

9.2
10.3
11.3
11.4
11.7

8.7
10.2
10.7

8.6
10.0

Calculated to per cent in
nut free from husk.

19.4
17.8
18.7
18.7
18.6
20.1
19.9
19.5
20.5
17.9

19.6
21.9
22.8
22.9
22.8
21.1
22.4
21.7
19.5
21.0

38.8
41.3
38.6
37.9
38.3
37.4
38.2
38.2
34.5
41.1

21. 6 38. 4

12.6
14.0
14.6
14.6
14.6
13.5
14.4
13.9
12.5
13.4

13.8

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Very little difference can be observed between tbese two varieties; tlie
average weigbt is almost exactly the same; the percentage of husk and
shell is somewhat lower in the yellow nuts, but this advantage to a large
extent is counterbalanced by their percentage in milk, so that the amount
of meat in the two remains practically the same. The yellow nuts
average 272 grams of anhydrous copra against 238 grams in the green
ones, which is quite decidedly in favor of the former.

Unfortunately, the copra from Series IX was spoiled in transit to
Manila. Calculations on the oil contents of this series were therefore
based on the assumption that this copra would have contained 04 per
cent oil — that is, the same percentage as that found in Series VIII.
Figuring the yield of oil on this basis, we have an average of 174 grams
for the yellow nuts against 154 for the green ones. However, it will be
noticed that these tables show a difference of over 100 grams in each
series between the maximum and minimum weight of oil, therefore if
another series of analyses of nuts from these two trees were to be made
possibly the slight advantage in favor of the yellow nuts might be
reversed. At any rate it may be concluded that the color of a nut has
very little, if any, influence on its composition.

Nuts from different localities. — In order to test the truth of the state-
ment that coconuts produced by trees growing along the seashore are of
a quality superior to those taken from farther inland, ten nuts were
selected at random from a large pile gathered near the sea and analyzed
as shown in the accompanying Series X, while a like number was secured
from a similar one containing the product of trees growing some 1,800
feet inland (Series XI).

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Series X. — Ten mtlxfmut <i ftife nf 1,000 taken from tree* nenv the sea.

Hu.sk. j N '^;^ nUS ! Shell

| Moat.

No,

'53

^ i

S j
o 1

H i

be
1

a 1 bo

* ! 1

a, ! £

i 1 s

a. ! £

v ' bo

£ i 2

i
c

c .
53 «

c .

1»

3, 125 ; 1

420

45.4 i 1,705

54.6 i 310

9 9

745

23. 8

54.3

45.7

2'»

' i
2,165 !

033

29.2 1,532

70.8 1 285

13.2

027 29.0

59. 1

40.9

2,520 j 1

,210

48.0 1,310

52.0 ' 301

12.0

549 ; 21.8

54.8

45. 2

4>>

3,492 ; 1
2,292
3,215 1

, 500
992
, 355

44.7 | 1,932
43.3 1.300

55. 3

56. 7
57.9

425
300
359

12.1
13.1
11.2

775 j 22.2
608 ; 20.5
701 j 21.8

45.

57. 8
•19.8

55.
42. 2
50. 2

5 a

6<*

42.1

1,860

2, 785 1

-105

50. 4

1,380

49.6

291

10. 5

594

21.3

42. 2

57. 8

8''

2,512
3, 240

792
,320

31. 5

40.8

1,720
1,920

68. 5
59. 2

340
380

13.5
11.7

738
780

29. 4
21.1

57. 3
51.5

42.7

48. 5

10*

Average

2, 705

,170

42.3 1,595

57. 7

262

9.5

083 24.7 1

49. 7

50.3

2, 81 1

1 , 1\SG

41.8

1,625 1 58.2

325

11.7

080

24.4 j

ited to ]
free froi

52. 2

>er cen
31 husl

47.8

No.

Copra (anhydrous).

Milk.

Oil.

Calculi
nut

t in

03
O .

"53

<x>
a
u

PUi

34.7
32.7

fifi

u
o

12.9
17.1

'53

650
620

a>
o

20.9
28.6

'53

264
249

C
a>

8.4
11 ft

o3
t-t

1_ _.

404
370

05.3
67.3

18.2
18.6

43.7
40.9

23. 7
24.2

38.1
40.5

15. 5
10.3

2 _'

300

65.7

34.3

12.1

460

18.2

201

23.0

41.9

23.4

35.1

15. 4

4 _

349

64.0

36.0

10.0

732

21.0

224

6 4

22.0

40.1

18.1

37.9

11.6

349

69.8

30.2

15.2

392

17.1

244

10 1

23.1

46.8

26.8

30.1

18.7

.349
251
423
402
339

10.9
9.0
16.8
12. 4
12.3

800
495
642
760
650

24.9
17.8
25.6
23.4
23.5

19.3
21. 1
19.8
19.8
16.4

37.7
43.0
42.9
40.6

42.8

18.8
18.2
24.6
20.9
21.3

43.0
35.9
37.3
39.6
40.8

11.2
15.6
13.2

7 __ _

61.6
63.6

62.8

38.4
36.4
37.2

155
269
253

5.6
10.7
9. ft

Average

354

65.0

35.0

12.9

620

22.1

232

8.8

20.1

42.1

22.0

37.8

14.7

a Yellow-green.

b Brown.

c Yellow.

e Brown-yellow.

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Series XT. — Ten nut* from a pile of J, 000 taken from tree* inland almvt 1,800 feet.

No.

1»

2»>

3 b

4»>

6<>

7»>

9»

10'»

Average

4,114
2,500
2,512
2,763
2, 745
4, 102
2, 485
1,423
2, 675
3, 620

2,894

Husk.

1,612
865
652
863
815

1,592
525
425

1,000

1,170

39.2
34.6
26.0
31.2
29.7
38.8
21.1
29.9
37.4
32.3

952

32.0

Nut minus
husk.

2, 502
1,635
1,860
1,900
1,930
2,510
1,960
998
1,675
2, 450

1,942

60.8
65. 4
74.0
68.8
70.3
61.2
78.9
70.1
62.6
67.7

68.0

Shell.

Meat.

540
352
352
337
343
452
345
235
342
439

13.1
14.1
14.0
12.2
12. 5
11.0
13.9
16. 5
12.8
12.1

13.2

857
726
746
766
752
911
820
473
603
936

20.8
29.0
29.7
27.7
27.4
22. 2
33.0
33.2
22. 5
25. 9

45.3

50.9
57.

45. 4

51 . 2

45. 5
49.3

59. 3
37.3
49.3

54. 7

27.2 I 49.1

49.1
43.0
54. (»

48.8
54. 5
50.7
40.7
02. 7
50.7

50.9

Average

Copra (anhydrous).

57.7

59.8

425 I 65.1

59.3
63.7
62.0
58.8
61.4
63.5
67.8

61.9

42.3
40.2
34.9
40.7
36.3
38.0
41.2
38.6
36.5
32.2

9.4
14.8
16.9
12.6
14.0
10.1
16.3
19.7

8.4
12.7

38. 1 13. 5

Milk.

1,105
557
762
797
835

1,147
795
290

26.9
22.3
30.3
28.9
30.4
28.0
32.0
20.4
27.3
29.7

Oil.

5.4

8.8
11.0
7.5
8.9
6.3
9.6
12.1
5.3
8.6

Calculated to per cent in
nut free from husk.

21.6
21.5
18.9
17.7
17.8
18.0
17.6
23.5
20.4
17.9

27.6 230 8.4 | 19.5

34.2
44.4
40.1
40.3
38.9
36.3
41.8

15.5
22. 6
22.8
18.3
20.0
16.5
20.6

47.4 | 28.1

36.0

38.2

13.4
18.8

44.2
34.1
41.0
42.0
43.3
45.7
40.6
29.1
43.6
43.9

9.0
13.5
14.9
10.9
12.7
10.3
12.1
17.2

8.5
10.6

19.7 | 40.7

12.0

„ i

a Green.

c Yellow-green.

(l Yellow.

In selecting nuts for the two preceding series of analyses no attempt
was made to secure uniformity as to size and age. On the contrary, they
were picked out with a view of obtaining fairly representative samples of
the largest and of the smallest, as well as of the most and of the least
mature in each pile, so that they would vary through a wide range of
color and weight. On comparing the two lots it will be seen that the
results agree very closely. Series XI averages a little higher in the total
yield of copra, but the oil content of this copra is somewhat lower than in
Series X, so that they yield almost exactly the same quantity of oil per
nut. The proportion of husk taken from the seashore nuts (41.8) is
much larger than it is from those gathered from the interior (32), but

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this is compensated for by the fact that the percentage of milk in the nut,
free from husk, and of water in the fresh meat is considerably lower in
the former than in the latter. Therefore it appears to be very evident
that the superiority of trees growing near the sea is solely due to the
quantity and not to the quality of nuts they produce.

Analyses of large numbers of nuts. — As a check on these last results,
secured on a small scale, it was decided to determine the actual weight
of the various products of the coconut under the conditions ordinarily
obtaining in the manufacture of commercial copra, and, with this end
in view, 1,000 nuts were procured from trees growing near the seashore
and the same number from those standing in the interior. After lying
for one month the nuts were put through the regular process for making
copra which has previously been described. The weight in pounds of the
whole nuts, husks, meat and shells, dried shells, and copra was determined
directly on an ordinary Fairbanks scale, the meat and milk being obtained
by difference. Five hundred nuts from each lot were sun dried and 500
grill dried and the resulting weight of copra multiplied by two to give
the yield of 1,000 nuts by each method. For the determination of moist-
ure and oil in this copra, twenty samples were taken from each lot, cut
into small pieces, and quartered down to about 100 grams. The moisture
was determined at once, after which the copra was sealed and sent to
Manila to secure the determination of the oil content. Both moisture
and oil were determined in triplicate.

Series XII.

Portion determined.

Weight of 1,000___

Husks

Nuts minus husks
Meat and shell ___

Milk

Shell (dry)

Meat

Seashore nuts.

Weight in
kilos.

Per cent.

2,363

100.0

897

38.0

1,466

62.0

929

537

22.7

282

11.9

647

27.4

Inland nuts.

Weight in
kilos.

Per cent.

2,286

100.0

703

30.8

1,582

69.2

979
603

26.4

291

12.7

688

30.1

Portion determined.

Copra

Oil

Moisture in copra .
I Oil in copra

Seashore nuts.

Sun dried.

Weight
in kilos.

302.1
182. 2

Per
cent.

12.8
7.7
9.2

60.3

Grill dried.

Weight j Per
in kilos. | cent.

330.2 j
198.9 I

14.0

8.4
8.6
60.2

Inland nuts.

Sun dried.

Weight
in kilos.

322. 9
191.1

Per
cent.

14.1

8.4

59.2

Grill dried.

Weight Per
in kilos, cent.

333.0
189.8

14.6

8.3

10.1

57.0

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This work, performed as it was on a large scale, agrees rather more
closely with the results obtained from the series of ten nuts each than was
to be expected. Here, again, it may be observed that the proportion of
husk from the seashore nuts is considerably higher than it is from those
from the interior, while the total amount of water is correspondingly less,
so that nuts from the two localities yield practically the same amount of
copra and oil.

While weighing out 1,000 nuts from the seashore trees it was found
that 55 of them, or 5.5 per cent, were in such a bad condition as to be
unfit for making copra, and fresh nuts had to be substituted. Out of the
same number from the interior only 15 were spoiled. The cause of this
difference is probably found in the fact that the nuts from trees near the
sea fall upon harder ground and are therefore more apt to become bruised
and injured, and it is very possible that the inferior yield of sun-dried
as compared with kiln-dried copra, in the case of the seashore nuts, is
due to this. Given perfectly sound coconuts, the two methods of drying
should produce equal amounts of copra, but a green nut, or one which
has begun to decay, would undoubtedly be more subject to the attacks of
mold, bacteria, and insects during the comparatively long alternate
heating and cooling incident to the sun-drying process than if it were
dried quickly at a higher temperature.

The figures obtained in this last series on a commercial basis establish,
even more firmly than do the results of analyses alone, the fact that there
is practically no difference in quality between the nuts gathered along
the seashore and those from farther inland. They should also be of some
value as representing the average yield in copra and oil from nuts pro-
duced in the southern parts of the Islands.

NUTS FROM DAVAO.

The following analyses were made of ripe coconuts, collected near
Davao, about 1 mile inland from the sea. In this region two varieties of
trees have been noticed, one producing large nuts rather pointed in shape,
the other bearing a smaller, rounder fruit.

Series XIII consists of ten of the small nuts, Series XI Y of the large
variety. On examining these figures it will be noticed that Series XIII
shows very much the same proportion of its various constituents, as well
as the total of oil, as the average lot of ripe nuts from San Ramon.

Series XIV excels in total weight of oil simply because it is made up
of larger nuts. The percentage of oil in the nut, free from husk, is the
same in both series. The nuts in these two series were fairly uniform in
composition, with the exception of No. 7 in Series XIV, which had a
total weight of only 92 grams of oil, less than one-half of the average
amount.

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No.

1 _

2_
3_
4_
5_
6_
7 _
8_
9.
10.

81
Series XIII. — Daraonnt*, small.

No.

o
H

2,016
2, 220
1,902
2,151
2,153
1 , 823
2, 232
2,019
2,157
2,098

Hus

480
548
385
404
488
455
427
451
396
364

23.8
24.7

20. 2
18.8
22. 7
25.0
19.1

22. 3
18.3
17.3

Nut m
hus

1,536
1 , 672
1 , 517
1,747
1 , 665
1 , 368
1 , 805
1,568
1,761
1,734

in us

76.2
75. 3

79.8
81.2
77.3
75.

80.9
77.7
81.7

82.7

to
*S

296
347
317
35(5
360
272
337
300
370
382

ell.

672
639
644
721
665
531
786
(J48
673
717

o
w

o
a.

33.3
28.8
33.9
33.5
30.9
29.1
35. 2
32.1
31.2
34.2

'at.

c .

o ZJ

£*

51 . 8
46. 5
44.2
45.0
48. 5
56.2
57. 2
51.7
49.4

14.7
15.6
16.7
16.5
16.7
14.9
15.1
14.9
17.2
18.2

48.2
53. 5
55. 8
55.0
51.5
43.8
42.8
48.3
50.6
49.2

2_*

3 „ . .

4 _ _ _

8_ _ .

10 _

50. 8

Average

2, 077

440

21.2

1,637

78.8

334

16.1

669

32. 2

49.9

50. 1

Average

16.1
15.4
18.9
18.4
15.9
12.8
15. 1
15.5
15.8
16.8

pra.

C
0)

61.1

38.9

40.6

59. 4

51.5

48. 5

58.6

41.4

58. 2

41.8

60.8

39.2

58.6

41.4

54.5

45. 5

52. 3

47.7

51.2

48.8

54.7

45. 3

Milk.

568
686
556
670
640
565
682
62Q
718
635

28.2
30.9
29.2
31.2
29.7
31.0
30.6
30.7
33.3
30.3

634 .| 30. 5

Oil.

9.8
6.3
9.7
10.8
9.3
7.8
8.8
8.4
8.2
8.6

Calculated to per cent in
nut free from husk.

t/2

19.3
20.8
20.9
20.4
21.6
19.9
18.7
19.1
21.0
22.

182 I 8.8 20.4

43.7
38.2
42. 5
41.3
39.9
38.8
43.5
41.3
38.2
41.4

40.9

21.1
20.5
23.7
22.7
20. 6
17.0
18.6
20.0
19.3
20.4

20.4

37.0

41.0

36. 6

38.3

38. 5
41.3

37.8
39.6
40.8
36.6

12.9
8.3
12. 2
13.3
12.0
10.4
10.9
10.9
10.1
10.4

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Series XIV. — Davao nuts, large.

Husk.

No.

3,070
3,092
2, 391
2,737
2,483
2,367
1,897
2,271
2, 444
2, 526

29.6
23.4
25.7
23.4
30.3
32.3
32.0
29.2
20.2
20.4

Average _ 2,528 j 669 | 26.7

Nut minus
husk.

2,160
2,367
1,777
2,098
1,731
1,602
1,289
1,608
1,949
2,010

1,859

70.4
76.6
74.3
76.6
69.7
67.7
68.0
70.8
79.8
79.6

73.3

Shell, j

Meat.

14.7
15. 6
12.9
12.4
13.4
13.5
12.9
14.4
13.5
12.8

13.6

25.
27.4
31.9
31.5
28.8
29.0
28. 2
30.3
32.5
31.6

43.7
52. 3
53.9
47.7
54.5
43.9
31.2
47.4
49.9
51.6

56.3
47.7
46.1
52.3
45. 5
56.1
68.8
52.6
50.1
48.4

29.6

47.6

52. 4

Copra.

442
411
411
390
301
167
326
396
413

10.9
14.3
17.2
15.0
15.7
12.7
8.8
14.4
16.2
16.3

14.2

No.

Copra.

10».

59.3
62.9
60.7
64.1
65. 7
64.9
55. 3
61.0
63.8
60.8

Average __ ; 61.9

40.7
37.1
39.3
35.9
34.3
35.1
44.7
38.0
36.2
39.2

38.1

Milk.

Oil.

942
1,039
700
892
680
596
504
589
825
875

30.7
33.6
29.3
32. 6
27.4
25. 2
26. 5
25.9
33.8
34.6

30.0

199
278
250
263
256
195
92
199
253
251

6. 5
9.0

10.4
9.6

10.3
8.3
4.9
8.8

10.3
9.9

8.8

Calculated to per cent in
nut free from husk.

20.9
20.4
17.3
16.2
19.2
20.0
18.9
20.3
16.9
16.1

18.6

35. 5
35.7
42.9
41.1
41.3
42.8
41.5
42.8
40.8
39.8

40.4

15. 5
18.7
23.1
19.6
22. 5
18.8
13.0
20.3
20. 3

20. 6

43.6
43.9
39.4
42. 5
39.3
37. 2
39.1
36.6
42.3
43. 5

9.2
11.7
14.0
12.6
14.8
12.2

7.2
12. 4
13.0
12.2

12.0

a Oil separated from the milk, hence the nuts were very ripe.

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THE KEEPING QUALITIES AND THE CAUSES OF
RANCIDITY IN COCONUT OIL.

By Herbebt S. Walker.
{From the Chemical Laboratory, Bureau of Science.)

In almost every work on fats and oils, coconut oil is cited as being
especially prone to become rancid. Lewkowitsch * states that, when
fresh, it possesses a bland, pleasant taste and odor, but that on standing
it quickly becomes rancid. Samples analyzed by him contained from
5 to 25 per cent of free acid. Schestakoff 2 says that pure coconut
oil shows an acid value (milligrams of caustic potash) of from 2 to 5.
On standing under abnormal conditions, this may in one year rise to
60 or 70.

Coconut oil is in enormous demand as the basis of edible products such
as "vegetable butter," etc., and therefore it is of the utmost importance
to be able to produce an oil which, as nearly as possible, is free from
fatty acids, rancid odor or taste, and which at the same time may be
shipped without fear of deterioration.

The experiments to be described were undertaken with the view of
discovering the conditions which induce a rapid deterioration of coconut
oil, and, if possible, of ascertaining a means of improving its keeping
qualities. In the course of this work it was noticed that the oil does
not change with as great rapidity as is generally believed to be the case.
The ordinary commercial oil, bought in Manila, contains from 5 to 10

1 Lewkowitsch : Chemical Analysis of Oils, Fats, and Waxes.

2 Schestakoff : Uber den Gehalt an f reien Fettsauren natiirlicher Fette und Ole.
Chem. Rev. Fett. u. Hans. Ind. 9, 180.

36540 6 117

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118

per cent free acid, and there is no very great increase in acidity even
on prolonged standing. Mr. Richmond, of this laboratory, in some
experiments on a commercial oil, showed that it was not affected by
passing a current either of dry or of moist air through the liquid for five
days. An oil prepared by drying fresh coconut meat at 80° to 90° C,
and then extracting with petroleum ether, was sterilized and sealed in a
glass tube on August 16, 1904. At that time it contained 0.13 per cent
free acid (calculated as oleic). This sample was allowed to stand until
February 21, 1905, and it was then again tested, with the result that it
was in as good condition as at the time of the previous examination ; there
had been absolutely no increase in free acid. A sample of the same oil,
kept in a sealed tin tube, on February 21, 1905, contained 0.34 per cent
of free acid, an increase of only 0.21 per cent in six months. This same
oil was allowed to remain in tin, unsealed, until April 11, 1905; the
acidity had then increased to 0.46 per cent. On further standing in a
glass-stoppered bottle until August 16, 1905, the figure was 0.50 per cent.
An expressed oil from the same preparation of copra, kept under similar
conditions, showed :

Per cent.

February 21 0.77

April 11 0.78

August 16 0.96

This oil, from the start, had a slightly burnt odor and taste and in
time it deposited a dark-brown sediment. However, neither of the two
oils showed any signs of "rancidity" and even after a year had elapsed
they were almost as pleasant to the taste as when first prepared.

In order more fully to study the effect of age and method of prepara-
tion on the keeping qualities of coconut oil, the following samples were
prepared, their condition noted, and their exact titer determined. These
oils will be allowed to stand for several years if necessary, until final
results are obtained as to their respective rates of deterioration, but in
the meanwhile the change up to the present time is given in the table
which follows:

DESCRIPTION OF OILS USED AND DESCRIBED IN TABLE I.

(A) Expressed oil from vacuum-dried copra. Has been heated for two hours
at 100° and filtered twice through paper. A light-colored, clear oil with the
characteristic coconut taste and odor.

(B) An oil similar in every respect to "A" except that it was prepared from
copra dried at 80° to 90°, without vacuum.

(1) Fresh coconut meat grated and dried at 80° to 90° on August 16, 1904;
was allowed to stand in a covered specimen jar until March 11, 1905. At that
time it was still of a pleasant odor and taste, although both odor and taste were
rot quite as good as when the specimen was freshly prepared. No mold growth
was piesert. A sample of oil was expressed from a portion of this copra by
using a hydraulic press with a final pressure of 450 kilograms per square cen-

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timeter. This oil, after filtration, was of a light-yellow color and it was of a
pleasant, although slightly burnt, odor and taste.

(2) Oil No. 1 was heated at 100° for three hours, while at the same time a
current of air in a partial vacuum was passed through it. This process leaves
the color and free acid unchanged but removes almost all of the burnt odor,
leaving a bland, almost tasteless, oil.

(3) An oil from the same copra as Nos. 1 and 2 but prepared by extraction
with petroleum ether. Afterwards it was treated in the same manner as No. 2.
It differs from Nos. 1 and 2 in being practically colorless.

(4) Commercial coconut oil treated with alcohol and animal charcoal and then
filtered; the alcohol was afterwards distilled and recovered. This oil was rather
unpleasant to the taste, but it had no odor.

(5) Commercial coconut oil treated with live steam; this removes the odor,
but the unpleasant taste remains.

(6) Fresh meat, ground and dried in vacuum at 70° to 80°. The oil was ex-
pressed and once filtered; it possessed a very pleasant coconut-like odor and taste.
It still contained a considerable amount of sediment.

(7) Coconuts cut in halves and dried in vacuum at 75° to 85°. The oil ex-
pressed and filtered twice. It had a very pleasant odor and taste.

(8) The same oil as No. "7, heated at 100° for one and one-half hours and
filtered hot. ^

(9) The same as No. 7, heated at 100° for one and one-half hours, while at the
same time a current of air was passed through the oil under partial vacuum.
Filtered hot and bottled.

(10) Fresh coconut meat, ground and pressed in a hand press to remove most
of the milk. Afterwards this meat was dried completely by spreading it in the
sun for about five hours. The oil expressed from this copra was almost water
white and without taste or odor.

(11) Coconuts split in halves and dried in the sun for five days. Ground and
expressed. Yielded a cloudy, light-colored oil, very hard to filter, with a peculiar
but not unpleasant taste and odor. This sample was strained through cloth but
not filtered.

(12) Same as No. 11, strained and filtered slowly through paper.

(13) Same as No. 11, heated at 100° for two hours and filtered through paper.

(14) Fresh nuts, split in halves and allowed to stand during one week in the
air at room temperature (about 30°). A vigorous mold growth and an un-
pleasant odor developed. This moldy meat was dried in a vacuum and the oil
was expressed. This was highly colored and was rather unpleasant to taste
and smell.

(15) Commercial coconut oil shaken with 2 per cent of solid calcium oxide
(burned lime), heated to 100° and filtered. The filtrate was treated with animal
charcoal and again filtered; there resulted a colorless oil which was very free
from an unpleasant odor or taste.

(16) The same copra as that used for No. 1; was allowed to stand one month
longer in an open jar, then expressed.

(17) Oil expressed from vacuum-dried copra which had stood for one month
exposed to the air; the oil was heated to 100° and filtered.

(18) Expressed from sun-dried copra and treated in the same manner as
No. 17. Both of these samples were of as pleasant a taste as oils from fresh
copra. r ,

(19) Vacuum-dried copra which had stood in a closed desiccator o*ve<- wafer ftfr^
one month, and which had accumulated a very decided growth of moid/** ft was
dried for one hour and expressed. The oil had a considerable color and was
slightly unpleasant as to taste and odor. Heated to 100° and filtered.

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(20) Sun-dried copra treated in the same way as No. 19. Yielded an oil
somewhat darker in color but otherwise much the same as No. 19. Filtered
without heat.

(21) Same as No. 20, heated to 100° before filtering.

(22) The same copra as that used for samples 1 and 16 was allowed to stand
for three weeks over water and for one week in air, and then dried and pressed.
A vigorous mold growth appeared in the copra and a peculiar ethereal odor was
apparent. The oil itself was of a light-yellow color, with a pungent, rather
unpleasant, odor and an extremely disagreeable taste.

(23) Expressed from commercial copra, first quality, sun dried, Tacloban,
Leyte. The unfiltered oil is dark colored and cloudy, depositing a black sediment.

(24) Same as No. 23, filtered. Almost colorless.

(25) Expressed from commercial copra, grill dried, Laguna (second quality).
Not filtered.

(26) Same as No. 25, filtered. Light yellow in color.

( 27 ) Expressed from commercial copra, grill dried, Romblon ( considered second
quality). The filtered oil is light yellow in color.

(28) Expressed from commercial copra, first quality, sun dried, Iloilo. The
filtered oil is light yellow in color. 3

(29) "Lcmgis" coconut oil, prepared by the customary native process of grating
the fresh meat, exhausting it repeatedly with water, and boiling down the
emulsion thus obtained until it is nearly dry. The oil is then poured off from the
brown coagulum which sinks to the bottom of the vessel. A freshly prepared oil,
isolated in this manner, is very light in color and it possesses a decidedly pleasant
coconut odor and taste. Before filtration it is more or less turbid, owing to the
presence of a small amount of water and of albuminoids.

(30) Same as No. 29, filtered. The oil is water white.

(31) Best grade commercial coconut oil, probably made from fresh meat. It
is light colored but very turbid and contains considerable water and suspended
matter.

(32) Commercial coconut oil, probably made from copra. Very clear but
highly colored.

(33) Commercial coconut oil, Manila. Probably made from fresh meat. It
contained considerable suspended matter and water.

(34) Commercial coconut oil, Cebu. A highly colored "rancid" oil. Consider-
able sediment in the bottom of the bottle.

(35) Commercial coconut oil, Tayabas. A highly colored rancid oil made
from copra. It is only a few months old.

The following table shows the change in the amount of free acid
which has been produced in these oils while they were standing from
the time of their expression up to the date of writing. The free acid
was determined in each case by dissolving a known weight (about 5
grams) of oil in 50 cubic centimeters of neutralized absolute alcohol, and

3 The copras from which these last six samples of oils were made were secured
through the courtesy of Messrs. Smith, Bell & Co. and the Companla General
de Tabacos de Filipinas, and taken directly from their warehouses. The samples
obtained were the ordinary grades of copra, ready for export, and had been
», Scored for &bout two months, during the dry season. The oils, while not especially
4 ,«,ninpl$aJ3ant to the taste, were of a sufficiently rancid character to preclude their
use as edible products unless they were first subjected to a refining process.

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then titrating with aqueous potassium hydroxide, using phenol-

phthalei'n as an indicator :

Taklk I. — Percentage free fatty aciih (m oleic).

No.

A»
B_

l._
2._
3._
4__
5__
6_.
7__
8__
9__
10-
11__
12__
13__
14__
15__
16__
17__
18__

19. _

20. _
21__
22__
23__
24__
25..
26. _
27__
28__
29__
30__
31__
32__
33__
34__
35__

At start.

Two
months.

Four
months.

Six
months.

0. Of)

0.06

0.09

0.60

0.06

0.08

»>0.48

1.2

1.3

1.5

1.9

1.2

1.5

1.7

1.4

1.6

2.1

2.6

5.3
5.5
0.10

5.9

6.1
7.6
0.30

0.16

0.19

0.16

0.18

0.19

0.27

0.16

0.14

0.19

0.30

0.16

0.18

0.25

0.16

0.21

0.28

0.13

0.18

0.25

0.28

0.13

0.10

0.14

0.13

0.09

0.15

3.5

3.7

4.0

4.3

0.32
1.6

0.88
2.0

1.7

0.09

0.14

0.16

0.18

0.25

0.27

1.18

1.14

1.34

1.58

0.69

0.74

0.85

0.69

0.74

0.82

23.3
1.4

1.6

1.8

2.0

1.4

1.5

1.7

1.8

2.6

3.4

3.6

3.9

2.6

3.1

3.5

2.1

2.4

2.5

2.8

3.0

3.5

4.0

4.7

0.08

0.38

0.60

0.69

0.08

0.13

0.16

0.19

2.0

2.9

6.8

7.5

7.9

8.1

5.5

8.7

6.9
10.2

7.2
11.0

5.0

5.5

a Through the courtesy of Prof. A. H. Gill, of the Massachusetts Institute of Technology, I have
been given some further data on the keeping qualities of this oil. A sample packed in a sealed tin
can was shipped to him at Boston and tested there when it was about three months old. On arrival
it was described as being almost water white and of perfectly sweet odor. It then contained only
0.088 per cent free acid as oleic, a figure which corresponds very closely to that obtained here at the
same time.

t>This oil was^kept in a large bottle. A sample in a small bottle showed an acidity of only 0.09
at this time.

At the present time there has been so little change in any of these
samples that no very definite conclusions can be drawn as to the condi-
tions which cause rancidity on standing. However, it may be considered
as established that a pure, fresh, coconut oil can be prepared which con-
tains a minimum amount of free acid and which shows no unpleasant

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taste or odor. Such an oil very slowly increases in acidity, and, even
after standing for one year under ordinary conditions, may still be edible
without further purification. 4 Commercial oils, on the other hand, which
contain from 5 to 10 per cent of free acid when freshly prepared, deterio-
rate much more rapidly, even though they have been filtered and are free
from impurities. For example, No. 32, which, on first examination, had
6.8 per cent of free acid, increased in two months to 7.5 per cent. This
oil is very clear, bright, and dry, being entirely free from sediment or
turbidity of any kind. The samples prepared by us from fresh copra
ranged from 0.06 to 0.16 per cent, the increase in two months being so
small as to be almost negligible. Samples Nos. 1, 2, and 3, which
contained a little over 1 per cent of free acid when fresh, increased from
0.1 to 0.3 per cent in the same time.

In fact, the increase in free acid to be expected in an oil when it is
standing under ordinary conditions may almost be considered as being
roughly proportional to its initial acidity. There are also indications
that an oil from which albuminoids, etc., have been removed by filtration
will retain its original condition better than one containing the above
impurities. No. 6, for instance, which has been filtered once but which
contained a considerable sediment, increased in four months from 0.10
per cent to 0.19 per cent, while Nos. 7, 8, and 9, oils prepared in a
similar manner but filtered more thoroughly, only showed an increase in
the same time of from 0.16 per cent to 0.19 per cent of free acid. 5 This
fact was a little more noticeable among oils prepared from sun-dried
copra. Samples Nos. 11, 12, and 13 were taken from the same lot of oil,
the only difference being that No. 11 was left unfiltered, while the
impurities were removed as completely as possible from Nos. 12 and 13.
It will be noticed that No. 11, in six months, shows a total increase of 0.15
per cent free acid, having a little more than double its original acid value.
Nos. 12 and 13 have in the same time increased only 0.01 and 0.02 per
cent, respectively.

The oils prepared from commercial copra likewise show this distinction
to a greater or less extent. No. 25, an unfiltered oil, increased from 2.6
to 3.4 per cent in two months, while No. 26, which is the same oil filtered,
shows no change at all. However, contrary to expectations, the difference

4 The sudden increase of acidity in samples "A" and "B" between the fourth
and the sixth months is due to the abnormal conditions under which they were
kept at this time. The two samples when originally prepared were kept in
500-cubic centimeter bottles which were nearly full, but during the fourth and
fifth months they were opened so frequently for the purpose of taking samples
for aldehyde and peroxide tests that only about 25 cubic centimeters remained
in each bottle. The increase in acidity is probably due to a continuation of the
surface oxidation which is discussed in a later part of this paper. A portion
of sample "B" which had previously been removed to a smaller bottle showed
practically no change at the end of six months.

8 On further standing, however, the difference in this case is not so marked.

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in behavior between a filtered and an unfiltered oil is most pronounced
during the first few months. On longer standing, the acid values tend
to approach each other.

The most important fact brought out by this work is that by far the
greatest deterioration which an oil undergoes takes place in the copra
itself. After an oil has been expressed from the dried meat, its change
on standing is very slight compared with that which is found in the
same time while it is in the copra. For instance, sample No. 1 was
prepared from anhydrous copra, which had stood in a closed jar during
about seven months (under much better conditions than copra is ordi-
narily kept) ; its free acid was 1.2 per cent; an oil expressed from this
copra when it was fresh had only 0.77 per cent of free acid after it
had stood for seven months in tin ; this same copra after remaining three
weeks over water and one week more in the air yielded an oil containing
23.3 per cent free oleic acid. Samples Nos. 19 and 20 were prepared
from copra which, when fresh, gave an oil with almost no free acid.
Fresh coconut meat on standing for even a short time in the air becomes
covered with mold and produces an oil of a more or less rancid character
(cf. No. 14). No great amount of rancidity was developed in any case
until signs of mold or bacterial growth were visible on the surface of the
copra. From this it would seem very probable that the splitting up of
fat and the accompanying "rancidity" produced in copra are in a large
measure due to the action of micro-organisms, which have an excellent
culture medium in the sugar, albuminoids, and water which exist,
together with the oil, in coconut meat.

Koenig, Spiechermann, and Bremer, 6 in their valuable paper on the
decomposition of fats by micro-organisms, have conclusively shown
that cottonseed meal containing a sufficient amount of water, is attacked
by molds and bacteria, and that the oil therein is, on long standing,
almost completely destroyed. In the accompanying experiments the
methods used by these authors were followed, with certain modifications,
which consisted chiefly in substituting freshly prepared anhydrous copra
for cottonseed meal, and in paying especial attention to the amount of
free acid developed.

The copra used for this work was prepared by grinding up fresh
coconut meat and drying it at 90° to 100° C. under a partial vacuum,
until the meat was anhydrous. It was then kept over sulphuric acid,
to be used as needed. This product had become quite brown during the
prolonged drying, but yielded an almost colorless oil, of a sweet taste,
and which contained about 0.15 per cent free acid as oleic.

Ten-gram samples were weighed out in large, stoppered test tubes and
each tube wa£ inoculated with one drop of a solution made from some

8 Koenig, Spiechermann, und Bremer : Beitrage zur Zersetzung der Futter- und
Nahrungsmittel durch Kleinwesen. I. Die Fettverzehrenden Kleinwesen. Ztschr.
f. untersuch. d. Nahrungs-u. Genussmittel (1901), 4, 721, 769.

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old, moldy copra. A definite volume of distilled water was then added
to each, and all were allowed to stand for one week at room temperature
(25°-30° C.) and for the same length of time in an incubator at about
35° C, the tubes being opened every morning and any change in odor or
appearance noted. After two weeks the whole series was dried, weighed,
the oil extracted with chloroform, and its acidity determined.

No. 1.

No. 2.

No. 3.

No. 4.

No. 5.

No. 6.

No. 7.

No. 8.

No. 9.

Weight of dry

copra ■-

10.00

Weight of water

added

0.00

0.50

1.00

1.50

2.00

3.00

5.00

7.00

10.00

Percentage

moisture

0.00

4.76

9.09

13.04

16.67

23.08

33.33

41. 18

50.00

Weight of dry

copra at end

of experi-

ment

10.00

9.99

9.70

9.20

9.30

9.10

9.20

8.97

9.15

Gain ( + ) or

loss (— )

0.00

-0.01

-0.30

-0.80

-0.70

-0.90

-0.80

—1.03

—0.85

Weight of oil __

6.79

6.77

6.61

6.64

6.68

6.82

6.78

6. 67

6.84

Gain ( + ) or

loss (— )

0.00

-0. 02

-0.18

-0.15

-0.11

(+0.03)

-0.01

-0.12

( + 0.05)

Gain (+) or

loss (— ) of

substances

other than

oil

0.00

(+0.01)

—0. 12

-0.65

—0.59

-0.93

-0.79

-0.91

-0.90

Percentage

free acid

0.15

0.18

8.7

5.2

3.9

0.46

3.0

6.1

2.9

Nos. 1 and 2 remained unchanged in appearance and odor throughout the experi-
ment. Nos. 3, 4, and 5 developed a slight mold growth and a peculiar ethereal
odor, not especially unpleasant except in the case of No. 5. No. 6 showed no
mold growth but turned much darker than the others and almost from the start
possessed a very disagreeable odor. Nos. 7, 8, and 9 soon developed a sour smell,
which, however, was not so unpleasant as that of No. 6, but they showed no
mold until they had been placed in the incubator, when Nos. 7 and 8 became
covered with a vigorous white growth with numerous patches of red. 7 No. 9
remained unchanged in appearance.

The percentage of free acid in the oil here seems very closely to follow
the appearance of a visible mold growth in the copra, being at a
maximum in No. 3, where the mold first makes its appearance, decreasing
slowly, with added moisture, up to No. 6 (no mold growth in evidence) .
increasing again in Nos. 7 and 8 (reappearance of mold growth).

As might be expected in an experiment of so short a duration, the loss
in total weight of oil was in no case large, but it was sufficiently marked
to show that it also chiefly took place in those tubes which contained a

7 Subsequent experiments indicate that this growth in Nos. 7 and 8 was due
to a loss of moisture while in the incubator.

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growth of mold; the loss of substances other than oil, on the contrary,
was considerably less where the mold was most vigorous.

As nothing was known concerning the organisms with which these tubes
had been inoculated, it was decided to repeat this experiment, without
inoculating the tubes directly, but to start the growth by simply exposing
them to the action of such organisms as might be present in the air from
day to day. Therefore, the tubes were filled as before and allowed to
stand at room temperature for two weeks, being opened and exposed to the
air for a few minutes each day. A similar set was prepared at the same
time and afterwards given to Dr. Edwards, of this Bureau, for bacterio-
logical examination.

Weight of dry
copra

Weight of water
added

Percentage mois-
ture

Weight of dry
copra at end of
experiment

Gain ( + ) or loss
(-)

Weight of oil

Gain (+) or loss
(-)

Gain (+) or loss
(—) of substances
other than oil

Percentage free
acid

No. 1. i No. 2.

9.99

(-0.01)
6.83

(-0.01)

0.15

. 10.00

10.00

0.00
6.85

(+0.02)

0.17

No. 3.

10.00

1.00

9.67

-0.33
6.24

+0.26

11.8

No. 4. ; No. 5.

10.00 , 10.00

1.50

9.59

-0.41
6.18

+0.24

12.9

2.0Q

16.67

9.39

-0.61
6.54

-0.32

13.7

No. 6.

No. 7.

10.00

3.00

5.00

23. 08

33.33

9.11

9.42

-0.89

— 1. 58

6.92

6. 81

(+0.09)

-0.02

—0.98

-0.56

No. 8.

No. 9.

10.00

7.00

10.00

41.18

50.00

8.97

—1.03

6.83

0.00

—1.03

0.47

0.24

a This tube was broken while drying.

These tubes behaved very much like those which had been used in the previous
experiment, Nos. 4 and 5 showing a growth of mold and an ethereal odor in
four and No. 3 in six days; No. 6 darkened and became putrid, while Nos. 7, 8,
and 9 simply turned " sour."

The bacteriological examination showed no organisms to be growing in Nos. 1
and 2; bacteria were found in Nos. 3 to 9, inclusive, and molds in Nos. 3, 4, and 5
only; the latter were much more numerous than the bacteria in Nos. 3 and 4,
and about equally divided in No. 5.

The mold most commonly occurring in Nos. 3, 4, and 5 was identified
as Aspergillus flavus; others, mostly Aspergilli, were also found but as
yet have not been indentified. Quite a number of bacilli were isolated
in pure cultures, but no attempt at identification has yet been made. 8

8 Experiments are now being undertaken to study the action of pure cultures
of all these organisms on copra of varying degrees of moisture. The cultures
are being prepared by Dr. Edwards. The results will be published in a later
paper.

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In this series of tubes, as well as in the preceding one, a high acid
value, accompanied by a loss in weight of oil, is evident only in those
samples which have been attacked by molds — that is, in Nos, 3, 4, and 5,
which had a water content of from 9.09 to 16.67 per cent.

No. 6, the dark-colored sample with a very disagreeable odor, showed
a slight gain in the weight of oil, probably due to the production, by
organisms, of bodies other than oil which are soluble in chloroform.
In all the other samples the weight of the oil practically remained un-
changed. The large loss in substances other than oil (sugars, albumi-
noids, etc.) is confined, on the contrary, to those tubes in which bacteria
predominate — that is, those containing more than 16.67 per cent of
moisture — indicating that bacteria obtain their carbon and hydrogen
chiefly from the sugars, albuminoids, and cellulose which are present in
copra, while molds directly attack the oil. Whether molds alone can
split up and assimilate oil from copra, or whether they may not be
symbiotic with certain bacteria, remains to be established by means of the
experiments to be undertaken with pure cultures.

The most important point to be considered from a practical point of
view is the fact that copra containing as little as 9 per cent of moisture
is still attacked by molds, with the consequent production of free acid
and coloring matter as well as loss in weight of oil. Unfortunately, the
copra produced in the Philippine Islands ordinarily contains from 9 to
12 per cent of water, a condition which is the most favorable for mold
growth and for the deterioration of the oil. The remedy for this is
obvious. A more complete drying, to reduce the water content to 5 per
cent or less, will produce a copra which is unattacked by organisms. Such
a product, kept dry, will remain fresh and sweet for a long time. In
a previous part of this paper I have shown that copra, once sufficiently
dried, may be kept during the dry season in Manila without any change
whatsoever, but recent experiments prove this not to be the case during
'the rainy one, even with anhydrous copra.

Two samples of the latter, cut into fine pieces, were exposed, in open
specimen jars, for a period of one month. At the end of this time one
sample was covered to exclude air, while the other remained open. The
covered sample soon developed a slight mold growth and a characteristic
ethereal odor, and at the end of another month the oil extracted from
it contained free acid to the amount of 3 per cent. The sample left
uncovered for two months was not changed as much, for the oil from it
contained only 0.89 free acid. This is probably due to the fact that
during the time of exposure there occurred several comparatively dry
periods of from three to four days each, during which there was very
little rain, thus giving the specimen an opportunity to become partially
dry so that the beginning growth of any mold would be stopped. The
covered and uncovered samples were found to contain 7.8 and 6 per cent
of moisture, respectively, which indicates the marked influence of a

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comparatively small amount of water on the keeping qualities of copra.
As shown in the previous experiment, copra containing 4.76 per cent of
moisture remains practically unchanged on standing under conditions
which preclude the absorption of water, while that with 9.09 per cent
produced 11.8 per cent free acid in two weeks. Between these two
extremes come the two samples mentioned above, the one with 6 per cent
of water increasing to 0.89 per cent and that with 7.8 per cent rising to
3 per cent of free acid during a period of two months.

EXPERIMENTS ON COPRA DRYING.

Since the quick and thorough drying of copra lias been shown to be
of such vital importance in order to insure the production of a pure oil,
an investigation of various methods of copra drying has been made, taking
into consideration not only the processes common in these Islands but
also those which are used in other countries.

Sun drying. — As has been stated in the introduction to this series of
papers, the simplest and most primitive mode of drying copra is to
expose the nuts, cut in halves, to the action of the sun during about five '
days. This method, although it is a slow one, under favorable climatic
conditions produces a very fair quality of copra. However, a sudden
rainstorm or a succession of cloudy days is sufficient to start mold
and bacterial growth, with the consequent deterioration of the copra.
Considerable loss due to the attacks of insects and animals is also suffered
during the long period of drying, and the finished product very seldom
contains less than 9 per cent of moisture.

Grill drying. — A much quicker method is the one carried out by laying
the half nuts, face downward, on a bamboo grating placed over a slow
fire of coconut husks. After being dried in this manner over night the
nuts are removed from their shells and are then again placed over the
fire, where they are allowed to remain for from four to five hours longer.
This process, although it is cheap and comparatively rapid, has the
disadvantage of yielding a dark-colored product which has a smoke-like
taste and odor, and it also tends to form a hard, burnt coating over the
surface of the nut while the inside is left in a comparatively moist state,
a fact which is often taken advantage of by the small producers, who
sell their copra by weight. Commercial copra prepared in this way
contains from 9 to 13 per cent of moisture.

Hot-air drying. — This method of desiccation has been used successfully
for a long time in the preparation of coffee, cacao, dried fruits, etc., and
is at present in quite extensive use for the making of copra in Ceylon,
where it is said to give a very pure, light-colored product. The type of
apparatus used in that island essentially consists of a large chamber filled
with wire trays upon which the coconuts are placed and over which a

9 Tropical Agriculturalist, 23, No. 10, supplement.

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current of hot air, driven by a fan, is passed. In Trinidad, 10 British
West Indies, there is now in operation a rotary hot-air drier which, it
is stated, is better than any other apparatus now in use.

For the purpose of testing the efficiency of the stationary form of hot-air drier,
a double-walled, rectangular galvanized-iron box, having an internal capacity of
about 0.2 cubic meter, was constructed. Three galvanized-iron trays, perforated
at one end, were set in this box in such a manner that the stream of hot air
entering through a 20-centimeter pipe at the bottom was compelled to pass over
each in turn before escaping at the top of the apparatus. A constant current of
air was obtained by means of a small electric fan which was connected with a
section of 15-centimeter pipe, so arranged that it could be heated by a small
kerosene stove to any desired temperature. The apparatus had a maximum
capacity of 24 nuts split in halves or 12 nuts when shredded.

Experiment I. — Four nuts were split in halves and placed on the
bottom tray.

Temperature of entering air, 56° C.
Temperature of escaping air, 51° C.
Time of drying, 20 hours.

The copra dried at this comparatively low temperature was very white
and of the best quality. A sample of oil expressed from it contained
0.08 per cent free acid.

Experiment II. — The meat from twelve nuts was shredded by hand and
treated for one day in the same manner as in the preceding experiment;
it was then allowed to stand at room temperature over night and com-
pletely dried on the following day. The substance in the bottom tray
naturally desiccated much more rapidly than in the other two, therefore
as soon as one tray was completely dry it was removed and replaced by the
one just above it.

Temperature of entering air, 56° C.
Temperature of escaping air, 50° C.
Actual time of drying:

Top, 14J hours.

Middle, 12J hours.

Bottom, 9 $ hours.

The less completely dried copra in the two upper trays became slightly
"soured" while standing over night. This caused a slight increase in
free acid as follows :

Tray.

Per cent

free fatty

acid.

Top

0.32
0.16
0.13

Middle

Bottom _ _

10 Journal aV Agriculture Tropicale (1904), 103.

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Experiment III. — The meat from four nuts was shredded and placed
in the bottom tray, being stirred every half hour.

Temperature of entering air, 93° C.
Temperature of escaping air, 74° C.
Time of drying, 3} hours.

The copra thus produced Avas thoroughly dry, very white, and pleasant
to the taste. The oil expressed from it contained only 0.06 per cent
free fatty acid.

In Experiment II, as would naturally be expected, it is evident that
the meat farthest away from the entering air requires a much longer
time for drying than does that which lies closer to the bottom of the
box. This is due to the fact that the air gradually becomes cooler and
more completely saturated with water vapor as it passes over the moist
copra. For practical use, therefore, a drier should be equipped with
some sort of a mechanical carrier which would constantly introduce fresh
coconut meat at the coolest part of the machine and then bring it slowly
down toward the hottest portion.

Experiment IV. — This was undertaken in an endeavor to ascertain the
approximate time required completely to dry the fresh meat, introducing
it at the top of the apparatus and shifting it gradually toward the bottom.
Four trays, each containing the freshly grated meat of 4 coconuts, were
prepared, and three of these were placed in the drier simultaneously, tray
No. 1 being at the bottom. After the latter had become sufficiently dry,
it was removed from the apparatus and tray No. 2 moved down to take its
place; this was next replaced by No. 3, and finally in the same manner
by the moist sample No. 4.

Entering air, 95° C.
Escaping air, 70° C.
Actual time of drying:

No. 1, 4 i hours.

No. 2, 5J hours.

No. 3, 6| hours.

No. 4, 4 hours.

From the above experiments it may be concluded that the average time
of drying, where the apparatus is run continuously at 95° C, will
approximately be four hours.

The rotary drier. — A section of galvanized-iron pipe 20 centimeters in
diameter by 6 meters long was set up on wheels and connected with a
small electric motor so that it could be made to revolve at any desired
speed. The same current of hot air which was previously used for the
stationary drier was connected with this apparatus. Four strips of angle
iron extending throughout the length of the pipe served to keep the moist
copra in constant motion during the time of drying. After much pre-
liminary work to determine the proper inclination necessary to allow the
material to pass through the apparatus with sufficient slowness, it was

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found that by careful manipulation the grated meat from four nuts
could be dried in about two hours so as not to contain more than 6 per
cent of moisture. The only objection to this method consists in the
difficulty of regulating the speed with which the ground meat passes
from one end of the apparatus to the other. This is dependent on four
factors: (1) The number of revolutions per minute, (2) the angle of
inclination, (3) the specific gravity of the coconut meat, and (4) the
speed of the entering current of hot air. In the machine used here an
unfortunate tendency toward a separation of the moist from the dry
copra appeared; the dry particles, being lighter, were held back by the
current of air or even blown out through the upper end of the tube,
whereas the moist and consequently heavier pieces passed through too
quickly. When these mechanical difficulties are solved this should prove
the ideal method for drying coconut meat for oil-making purposes.

Vacuum drying. — The apparatus used was a small, barrel-shaped iron
chamber, about 34 centimeters in diameter and in length, insulated with
asbestos and heated by three hollow steam plates upon which the substance
to be dried was placed. The pump connected with this drier gave a
vacuum of about 660 millimeters (absolute pressure of 100 millimeters).

Experiment I. — Four coconuts (the maximum capacity of the ap-
paratus) were split in halves, after removing the outer husk, and kept
in the drier for three hours. The meat had then contracted sufficiently
to allow of its being removed from the shell. During this time the tem-
perature had gradually risen from 30° to 80°. The meat was then
subjected to a further drying during four hours, at the end of which time,
though not perfectly anhydrous, it was fully as dry as the ordinary
commercial article.

Actual time of drying, 7 hours.

Maximum temperature, 80° C.

Vacuum, 635 millimeters.

Steam pressure, about 0.7 kilo per square centimeter (10 pounds).

Experiment II. — The preceding experiment was repeated under prac-
tically the same conditions, except that the nuts were allowed to dry
completely without removing the shell.

Time of actual drying, 8 hours.

Maximum temperature, 80° C.

Vacuum, 648 millimeters.

Steam pressure, about 0.7 kilo per square centimeter (10 pounds).

Experiment III. — An attempt was made to shorten the time of drying
by increasing the steam pressure and having the machine hot before
putting in the nuts, the initial temperature being 75°.

Actual time of drying, 5J hours.

Maximum temperature, 85° C.

Vacuum, 640 millimeters.

Steam pressure, about 4.2 kilos per square centimeter (60 pounds).

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Experiment IV. — The meat from four nuts was ground and spread in a
layer of a depth of about 3 centimeters in shallow glass dishes. The
initial temperature was 60°.

Actual time of drying, 9 hours.

Maximum temperature, 75° V.

Vacuum, 660 millimeters.

Steam pressure, 0.7 kilo per square centimeter (about 10 pounds).

Experiment V. — Four coconuts were split in halves and put into the
machine, the latter being left partly open and with no vacuum.

Actual time of drying, 11 hours.

Highest temperature, 86° C.

Steam pressure, 0.7 kilo per square centimeter (about 10 pounds) .

Therefore, under the best conditions obtainable (temperature 85° and
vacuum 635 to 660 millimeters), the minimum time required for vacuum
drying was five and one-half hours. 11

If we are to form our judgment from the great efficiency of the
vacuum evaporators used for sugar solutions and for many other liquids,
it might be supposed that this process would be equally advantageous
for coconuts. However, the two conditions are altogether different. In
the case of solutions we have a thin layer of liquid in direct contact with
a heated surface, the evaporation taking place so rapidly that the space
above the liquid is constantly saturated with moisture; the main object
of these machines is to remove and condense the surplus water vapor as
rapidly as possible and by so doing to allow the evaporation to proceed at
a comparatively low temperature. The water in coconut meat, on the
other hand, which at the most is not greater than 50 per cent of the
total weight of material, under the best conditions, diffuses very slowly
through the cells of the copra to the surface, the removal of moisture-
laden air therefore becoming a matter of secondary importance. The
principal consideration is the constant application of as much heat to
the entire surface of the material as the latter can endure without becom-
ing burnt. That this condition is not fulfilled in the best manner by
a vacuum drier is chiefly due to the poor conductivity of the rarified air
which it is necessary to heat. Although the temperature of the steam
plates in the drying oven is from 100° to 110°, that of the partial
vacuum immediately above and surrounding the copra, even after several
hours, rarely rises above 75°. To this local superheating for a long
period of time at the point of contact with the plates, probably is due the
brown color and slightly burnt taste which vacuum-dried copra almost
invariably possesses.

For the sake of comparison I append the following table showing the

11 This does not include the time necessary to produce steam and to heat up the
drier. These items must be considered unless the apparatus is to run con-
tinuously.

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approximate time required to dry copra under the most favorable condi-
tions by each of the methods previously considered :

Method. Time.

I Sun i 5 days. '

j Grill j 10 to 12 hours.

i Hot air (box) 3£ to 4 hours.

' Hot air (rotary) 2 to 3 hours. ]

| Vacuum 5| to 65 hours, j

The quality of the copra produced by the hot-air box drier is very
much superior to that yielded by any other method, since it is perfectly *
white and dry, retaining the pleasant odor and taste of fresh coconut
meat. For oil-making purposes the rotary apparatus, because it lends
itself to a continuous process and requires considerably less time, recom-
mends itself especially, although its product does not present quite so
pleasing an appearance. Either of these two methods, on account of
their cheapness and simplicity, should be preferred to vacuum drying.

Gentrifugating. — Another method of drying suggests itself, which
should prove to be very efficient, although, owing to lack of facilities,
I have not as yet been able to give it a practical test. This is to extract
the meat from coconuts by means of a rotary burr and to run this
product directly into a powerful centrifugal from which the greater part
of the water would be thrown off at once. A comparatively short, sup-
plementary drying by means of hot air would then suffice to prepare copra
for expressing the oil. Another point in favor of this method is that the
copra resulting therefrom, having lost most of its sugar and albuminoids
together with its water in the process of centrifugation, would be able to
withstand a higher temperature while drying (with a resulting economy
of time) without showing the same tendency to turn brown. Once dry, it
could be stored with less danger of deterioration through mold action than
material prepared by ordinary methods. The objection may be raised
that, during the centrifugation, a considerable amount of oil together
with the water would be thrown off from the fresh meat, and that this
would either entirely be lost or would necessitate much labor for its
recovery. This, to a certain extent, is true, as the water in coconut meat
exists in the form of a cream-like emulsion with oil, sugar, and albu-
minoids. A sample of this "coconut cream," prepared by expressing the
fresh meat in a hand press, was, on analysis, found to have a specific
gravity of 1.012 at 30° C. and to consist of —

Per cent.

Water 56.3

Total solids. __. 43. 7

Ash 1.2

Fat 33.4

Proteid (N x 6.25) 12 4.1

Total sugar as invert sugar 5.0

12 Determination made by Mr. Richmond, of this laboratory.

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The above results show that it approximates in nutritive properties
the composition of a rich, natural cream; it is very pleasant and sweet
to the taste, possesses an agreeable odor, and, when sterilized and properly
sealed, will remain indefinitely in a fresh condition. Such a product
could be used as as substitute for all of the purposes to which the so-
called "evaporated creams/' now on the market, are put, and it might
prove to be one of the most valuable by-products of the coconut-oil
industry.

THE ACTION OF ORGANISMS ON COCONUT OIL UNDER VARYING CONDITIONS.

Although, as has been shown above, the character of a coconut oil in
regard to free acid, odor, and taste is determined chiefly by the quality of
the copra used for its production, there is also in most commercial oils
a slow but steady deterioration, amounting in the worst cases to a rise
of about 0.5 per cent per month (cf. sample No. 31, p. 120), while
with pure, filtered oils this reaches only a few hundredths per cent in
the same time. It has been remarked above that samples of oil which
contain suspended impurities and water, as a rule, increase in their
content of free acid somewhat more rapidly than do similar ones which
have been clarified; a result to be expected, if, as is the case with copra,
decomposition is due to micro-organisms, since it has been proven that
bacteria and molds do not live for any length of time in pure oil. 13

The influence of impurities on the keeping qualities of oils was noticed as
early as 1855 by Pelouze, 14 who observed that various oleaginous seeds, when
crushed and extracted at once, yielded almost neutral oils, whereas if, after
being crushed, they were allowed to stand for some time before extraction, the
oil then produced contained a large amount of free acid. He considered this
action to be due to a "ferment" similar to that producing alcohol from sugar.

Pastrovich and Ulzer, 15 using a mixture of oleomargarine with 0.5 per cent
casein and 1 per cent water, observed an increase of acidity from 0.888 to 1.259
per cent in one week, and in fourteen weeks 0.888 to 10.270 per cent. They
make no attempt to explain this effect, evidently attributing the saponification
to some change brought about directly by the presence of albuminoids, although
it is very probable that it was produced by bacteria or molds.

The following experiments were undertaken with a view of accentuat-
ing this difference in keeping qualities between pure and impure oils by
exposing them directly to the action of micro-organisms under similar
conditions.

About 20 cubic centimeters each of samples Nos. 6, 8, and 11 were
poured into small beakers and placed in a covered specimen jar containing

13 E. Kitsert: Untersuchungen iiber das Ranzigwerden der Fette. Ghem. Gentrb.
(1890), 507, 575, 813.

14 M. J. Pelouze : Memoir, sur la saponification des huiles sous l'influence des
matieres qui les accompagnent dans les grains. Gompt. Rend. (1855), 40; 605.

16 Pastrovich u. Ulzer : Ueber den Einfluss der Gegenwart verschiedener Eiweiss-
korper auf Fette. Ber. d. chem. Gesell. (1903), 36, 209.
36540 7

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a little moldy copra together with a beaker of water to insure an abun-
dance of moisture. They were then allowed to stand at room temperature
(25° to 30° C.) for two months. Their change in acid value is shown
as follows :

Number of oil.

After standing one
month.

After standing two
months.

F. F. A.

in oil

exposed to

mold.

F. F. A.
in oil in
original
bottles.

0. 10
0.14
0.18

F. F. A. | F. F. A.

in oil ! in oil in

exposed to i original

mold. bottles.

0.22
0.23
0.22

20 ! 0.17

0. 20 ! 0. 17
0.83 ! 0.22

A slight increase of acidity was evident in each of these samples, but
No. 11, an unfiltered, very turbid oil, was decomposed much more rapidly
than either of the others. It also was characteristically rancid in odor
and taste and contained a visible mold growth.

Since a marked difference was shown in the behavior of these oils, it
was decided to observe the effect of the addition of small quantities of
nutrient matter and of water on the rise in the free-acid contents of a
pure oil. The nutrient material which was used was prepared from
"latic," a coagulated residue produced in the native process of making
oil, by boiling down an emulsion of fresh coconut meat. This residue,
when dried and extracted with chloroform, yields a light-brown powder,
partially soluble in water and of a sweetish, not unpleasant, taste. It
consists chiefly of albumin and sugar. The following samples were
prepared, using pure, fresh oil as a base :

A. 25 cubic centimeters oil -j- 0. 25 grams "latic."

B. 25 cubic centimeters oil -f 0. 25 grams * 'latic" -f- 0. 25 cubic

centimeters water.

C. Control of pure oil.

Each of these samples was placed in a 50-cubic centimeter glass bottle
inoculated with one drop of the moldy oil (No. 11) used in the previous experi-
ments, and allowed to stand for one week at room temperature, and, after
determining the increase in acidity, for one week in the incubator at 35°.
Finally, the acidity was tested after the oil was allowed to stand for two months
longer at room temperature.

Sample.
A

Initial
acidity.

One
week at

room
tempera-
ture.

One
week at
35° C.

Two

months at
room

tempera-
ture.

0.10

0.11

0.13

0.27

0.10

0.25

0.09

3.8

0.10

0.11

0.13

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135

The following table gives the results of a similar experiment in which 10 cubic
centimeters of the oil to be tested were inoculated with a drop of moldy oil,
then poured out in a Petrie dish, which was placed in a closed specimen jar
over a little moist, moldy copra, and allowed to stand in the incubator at 33°
to 35° C. for one week:

Nature of oil.

Initial
acidity.

One week

at
33°-35° C.

No. 29

0.10
0.10

0.10

0.50

No. 30

0.21

No. 30 + 1 per cent "latic"
+ 1 per cent water

8.63

The last sample, which showed the greatest increase in acidity I have
yet been able to produce in a short time, was almost completely covered
by a greenish-yellow mold; similar to that noticed on copra, and it had
the characteristic odor of a rancid oil.

In the light of these latter experiments there can be no doubt of the fact
that coconut oil, provided it contains sufficient moisture and nutrient
matter, is attacked by micro-organisms, principally molds, with an accom-
panying production of free acid and of a disagreeable taste and odor.
This is the principal cause of "rancidity" in coconut oil, if by "rancidity"
we mean a high acid content and a bad taste and odor. Whether this fat
splitting is directly due to a life process of the molds or to an enzyme
secreted by them is a problem which has not yet been solved. However,
it seems highly probable that these molds produce a slowly acting enzyme,
soluble in oil, which continues its hydrolytic action even after the or-
ganisms themselves are dead. This would account for the steady increase
in free acid of some commercial oils which are perfectly clear and free
from impurities and which have been proven to contain no living bacteria
or molds. Experiments are now being carried on to clear up this point.

OTHER FACTORS INFLUENCING THE ACIDITY OF OIL.

Effect of sunlight. — Twenty-five cubic centimeters each of samples "A"
and "11" (see table, p. 119) were placed in 50-cubic centimeter glass-
stoppered bottles and allowed to stand in the sun for one month. At the
end of this time "A" contained 0.22 per cent and "11" 0.24 per cent of
free acid, while at the same time the original samples, "A" and "11"
showed 0.06 and 0.18 per cent, respectively. No marked change in taste
or odor could be detected. The acid content of the pure sample "A"
appears to have increased considerably more than that of " 11," due
probably to its contamination with a few drops of water during a hea*vy
rain. However, the total amount of acid developed was so small that
the experiment was not repeated.

Effective of heat and moisture. — Several samples of oil were heated
at 100° for periods up to twenty-four hours with no change in acid

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value. However, on heating in a sealed tube, considerable alteration took
place, as is shown in the following : Samples from No. "B" and from that
portion of No. 11 which had been exposed to sunlight were heated in
sealed tubes at about 160° for ten hours. "B" changed in percentage
of free acid from 0.06 to 0.90, but was unchanged in color, odor, or taste.
"11" rose from 0.24 per cent to 2.05 per cent under the same conditions,
and possessed a very disagreeable odor and a nauseating taste. It also
showed a considerable increase in color, probably due to decomposed
albumin, etc. The change taking place in the sample was demonstrated
to be a simple hydrolysis by heat and moisture. In the next experiment,
both "B" and "11" (original samples) were dried very carefully by
passing through t*hem a current of dry air for seven hours at 100° ; 10
cubic centimeters each of the dry oils were then sealed in glass tubes and
heated at about 160° for ten hours. For comparison, two more tubes
of oil were subjected to the same conditions, one containing 10 cubic
centimeters of sample 11 (undried), the other 10 cubic centimeters of
the dried oil "B" plus 3 drops of water.

Oil.

"B"dry___
"B" + aq__

11 dry

11 original-

Before
heating.

After
heating.

0.07

0.09

0.07

14.8

0.18

0.19

0.18

0.46

In neither of the samples marked "B" was a bad odor or any color
produced, though the hydrolyzed sample was slightly unpleasant to the
taste, owing to the large amount of free acid present. However, both the
similarly treated tubes containing oil No. 11, in spite of their low acid
value, were decidedly disagreeable to the taste and smell and presented a
decomposed appearance.

FACTORS WHICH CAUSE RANCIDITY IN OIL.

The average person, if asked to judge of the quality of these four
heated oils by the sense of taste and smell alone, would almost invariably
say that both samples of oil No. 11 were "rancid" and that the other two
were fairly pure, whereas, judging from the amount of free acid present,
one might consider " B + aq." as the only sample containing a marked
amount of rancidity. From the above it is evident that rancidity and
free acid are not by any means synonymous and that the cause of the
former must be sought elsewhere than in the percentage of the latter.

Lewkowitsch applies the term "rancidity" only to those fats which contain
an excess of free fatty acids due to the action of air.

Alder Wright 16 gives a resume" of the work done on this subject and concludes

"Alder Wright: Fixed Oils, Fats, Butters, and Waxes, second edition (1903),
168.

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that rancidity is the alteration which oils and fats undergo when not protected
from the influence of air and light. "Such oils/' he says, "acquire a sharp, dis-
agreeable taste and odor, their proportion of free acids gradually increases, and
they undergo various other chemical alterations."

Schmid '" differentiates between "sour fats," "rancid fats," and "sour and
rancid fats." "A fat is sour," he says, "when its content of free fatty acids is
abnormally high but the free glycerine is unchanged. A fat is rancid when the
proportion of free fatty acids is not high but the free glycerine has been oxidized
partially or completely to aldehydes and ketones. A fat is rancid and sour
when it contains a large amount of free acid together with oxidation products
of glycerine."' As a test for rancidity he proposes a 1 per cent solution of
m. phenylendiamin.

Scala 18 found oenanthylic aldehyde among other substances present in rancid
olive oil, and assumes that this body gives the characteristic odor and taste
termed "rancidity."

Bianchi 19 proposes, as a test for rancidity, to shake up a little of the oil in
question with fuchsin-sulphurous acid, a violet-red color indicating rancidity.

Brown 20 uses this same test in the study of butter fat, and presumes that the
rancid odor is due to acrolein. Various other tests for rancidity have been
proposed, all depending on the presence of aldehydes.

The most satisfactory, in my experience, is that with fuchsin-sul-
phurous acid, shaking up about equal parts of oil and reagent. Nearly
all the samples of coconut oil prepared in this laboratory, after standing
for several months, responded to this* test, but they gave, not a violet red,
as has been stated to be the case with other rancid oils, but a more or less
blue coloration with only a slight tinge of red. The above review of the
literature will demonstrate that the causes of rancidity are by no means
clear. Certainly cenanthylic aldehyde has not an intensely disagreeable
odor; acrolein has, but then it gives a red and not a blue color with
fuchsin-sulphurous acid.

ACTIVE OXYGEN IN COCONUT OIL WHICH HAS BEEN STANDING.

Another peculiarity of pure coconut oil is that, after it has been stand-
ing exposed to light and air for a few months, it almost invariably
contains active oxygen. Five cubic centimeters of sample " A," shaken
in an Ehrlenmeyer flask with a mixture of 50 cubic centimeters of water,
5 cubic centimeters glacial acetic acid, and 1 gram potassium iodide and
allowed to stand for one hour, produced a deep-yellow coloration in the

N"
water solution, requiring 0.25 cubic centimeter — sodium thiosulfate for

decolorization. A blank test, with freshly prepared oil, remained per-
fectly colorless during the same time. A simple way of performing this
test is to saturate a strip of starch iodide paper with the oil in question,

17 A. Schmid: Zur Priifung der Fette auf Ranziditat. Z. Anal. Gh. (1901), 37,
301.

18 Alberto Scala: Staz. sper. Agrar. ital, 30, 613, Gentrbl. (1898), 439.

19 Gentrbl. (1898), II, 948.

20 Brown: The Chemistry of Butter Fat. Jour. Amer. Ghem. Soc. (1899), 21,
975.

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place it on a glass plate, and carefully add one drop of 10 per cent acetic
acid. When old oil is used, a blue ring appears around the drop of acid in
from one to five hours, whereas a freshly prepared sample remains un-
colored for twenty-four hours or more, provided the test paper is kept
under a bell jar to exclude laboratory fumes. This reaction is at least as
delicate as any of the tests for rancidity based on the presence of aldehyde.
Whether it is given by other rancid oils can not be stated at present, for I
have as yet failed to find in the chemical literature any mention of such
oxidizing substances in oil. The following is a table showing the reaction
of our samples of coconut oil with fuch sin-sulphurous acid and with
starch iodide, together with their age and acidity at the time of testing.
For the previous history of these oils, see page

io_.
n_.

12_.
13_.
14..
15_.
16..
17_.
18-
19_.
20_.
21_.
22_.
23_.
24_.
25_.
26_.
27-
28_.
29_.
30-
31-
32_.
33_.
34_
35_.

No.

Approxi-
mate age,
in months,
at time of
testing.

15
5

5£
5*

Approxi-
mate per-
centage
F. F. A.

0.1
0.1
1.5
1.5
2.1
5.9
7.6
0.2
0.2
0.2
0.2
0.2
0.3
0.1
0.1
4.0
0.9
2.0
0.1
0.2
1.2
0.7
0.7

23.3
1.6
1.5
3.4
2.6
2.4
3.5
0.1
0.4
3.5
7.8
7.0

10.2
5.0

Color with fuchsin-sulphurous
acid.

Strong blue

Blue-red

Strong blue

No color

Strong blue

No color

Red

Light blue

Strong blue

Moderate blue

Strong blue

Light blue__-L

Very strong blue _

No color

Light blue

Trace

Moderate blue

No color

Strong blue

No color

Test
for perox-
ides.

Trace.

+
+
+
+
Trace.
+
+
+
+
+
+
+

Trace.

4-
+
+

a Very strong.

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In examining this table it will be noticed that in almost every case a
distinct blue color with SchifFs reagent is accompanied by a positive test
for peroxide, and, in the two cases where a red coloration predominates,
the peroxide test is negative. The strongest tests for both peroxide and
aldehyde were given by samples A and B — two very pure oils — while,
contrary to our expectations, the commercial oils as a rule either failed to
respond entirely or gave very weak tests, though they were infinitely
worse than the pure samples in every other particular. The only change
noticeable in samples A and B, on standing, was the development of a
peculiar, pungent, "strong" odor and a slight burning "after taste ;" other-
wise they were practically the same as when freshly prepared. Just what
this "strong" odor in pure oils is caused by can not at present be stated,
although the subject is now being investigated. It can hardly be caused
by either cenanthol or acrolein, as both these substances, when mixed
with oil, give a red and not a blue color with SchifFs reagent. Glycerine
aldehyde 21 under certain conditions produces a blue-red coloration with
this test, but it has no odor. However, the process by which this change
is produced is undoubtedly due to direct oxidation by light and air, since
bacterial or mold action may be excluded in the case of a pure oil. That it
is largely a surface action is indicated by the facts that (1) samples A
and B, which were kept in large bottles, about half full, have deteriorated
in five months to a much greater extent than have other samples of pure
oil which were kept in small, nearly full bottles for over a year; (2) both
the aldehyde and peroxide tests were given by samples of fresh oil which
were exposed to the air on strips of filter paper for one or two weeks; 22
(3) the same effect can be produced by treating fresh oil with platinum
black for a few hours, or by heating it, exposed in a thin layer, to 100°
for ten or twelve hours.

A possible explanation of this production of rancidity in pure oils is
that a small percentage of fatty acid is oxidized to an oxyacid, which in
turn forms a lactone, and (assuming the formation of hydrogen peroxide)
the latter would give rise to a peracid, which, in turn, would oxidize the
free glycerine to an aldehyde. The absence of peroxide and, as a rule, of
aldehyde in commercial coconut oils, or in those purposely subjected to
the action of micro-organisms, may be due to the presence of sugars and
other reducing substances commonly present in the impure oils, or to the
fact that the glycerine set free by mold action is completely oxidized to
carbon dioxide and water. The nonexistence of free glycerine in highly
rancid fats has been noted by Sparth 23 and other observers. This ques-
tion of the products arising from the oxidation of pure coconut oil by air
is now being taken up more thoroughly, and the results will be published
in a later paper. However, from a commercial point of view, it is of

21 E. Fischer u. Tafel. Ber. d. Chem. Gesell. ( 1887.) , 20, 3384.

22 Freer & Novy: Amer. Chem. J. (1902), 27, 161.
2:i Zt. Anal. Ch. (1896), 35, 471.

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comparatively little importance, when one considers the marked deteriora-
tion produced by micro-organisms acting on copra and impure oil. If
stored in nearly air-tight containers very little if any oxidation should
take place even on long standing or on transportation. The main points
to remember are that the copra from which oil is made should be fresh
and be prepared under as good conditions of drying as possible and the oil
should be thoroughly dried and filtered until absolutely clear. If properly
prepared, it should then be capable of shipment without noticeable dete-
rioration. It is obvious that the best results will be obtained by express-
ing the oil in the country in which copra is dried, and by using the best
machinery for preparing the latter.

SUMMARY.

Soil. — In attempting by means of soil analyses to explain why coconut
trees growing near the seashore are more prolific than those planted
farther inland, it was observed that —

(1) Chemically, there is very little difference in soils from the two
localities, those from inland regions being, if anything, a little more
fertile.

(2) The salt water from the sea has no influence on trees in its vicinity,
as only amounts of chlorine so small as to be negligible were found to be
present even at the bases of coconut trees which were actually growing on
the beach.

(3) The greater porosity of soils near the sea, coupled with the fact
that they are, as a rule, practically saturated with water at a distance of
only a few feet beneath the surface of the ground, is the principal reason
why they are more suitable for trees like the coconut, which require an
enormous quantity of water for their growth.

(4) Although good coconut soils are apparently almost devoid of fertil-
ity, yet, taking into account the character of coconut roots and the large
area from which each tree draws nourishment, it can be demonstrated
that there exists an ample supply of nutriment for their growth.

The nut; age in reference to quality. — (1) The variations among in-
dividual nuts is sufficiently great to render exact conclusions from analyt-
ical data difficult, but, taking the average of a number of determinations,
there appears to be a slight increase in the proportion of meat, copra, and
oil in nuts which have been stored up to a maximum time of three months
after cutting. Beyond this period there is a decided decrease in these
constituents. Nuts taken from the same tree show somewhat less indi-
vidual variation.

(2) Four series of ten nuts each, of varying degrees of ripeness, showed
a marked difference in the amount of copra and of oil to be obtainable
from them, the percentage of the oil in a green nut being only about
one-half of that which tt is when the nut is fully ripe. This ripening
process continues to some extent, on storage, after cutting.

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(3) Analyses of coconuts from the same locality, but having husks of
different color, prove that the color of a nut has very little if any influence
on its composition.

(4) The difference between trees near the seashore and those farther
inland is solely in the quantity, not in the quality, of nuts which they
produce, coconuts from inland regions averaging fully as well as those
from the beach. This fact is shown both by analyses and by practical
tests on a large scale.

(5) Analyses were made of twenty ripe coconuts from Davao, Minda-
nao, and they were found to have very much the same proportion of the
various constituents and to give the same total yield of oil as the average
lot of ripe nuts from San Eamon.

(6) Coconut oil is generally stated to have a great tendency to become
rancid, but all the experiments made in this laboratory show that, when
once prepared in a pure state, its keeping qualities are equal if not
superior to those of most other vegetable fats and oils. This popular
fallacy in regard to coconut oil probably arose from the inability or
disinclination on the part of most observers to procure pure samples, as
the commercial product unquestionably has a high acid value and a bad
odor, and deteriorates with fair rapidity, this change being greater as a
rule the greater the initial acidity of the oil.

(7) Most of the free acid and the accompanying bad odor and taste
is produced in the copra itself before the oil has been expressed. The
oil from a sample of copra which had been cut into fine pieces and exposed
to moist air for one month increased in acidity from 1.5 to 23.3 per cent.

(8) The hydrolysis and subsequent destruction of fat in copra is
brought about by molds (the greater part of which are Aspergilli) , acting
either alone or in symbiosis with certain bacteria, the condition most
favorable to this growth being a moderately high, constant temperature
and a water content of from about 9 to 17 per cent. No organisms were
found growing on a sample containing 4.76 per cent of moisture and no
change in acidity took place. Samples containing from 23 to 50 per
cent of water were infested by several species of bacteria which subsisted
on the nonfatty portion of the copra but produced very little free acid
from the oil. No molds were found in these samples.

(9) Ordinarily, commercial copra contains from 9 to 12 per cent of
moisture, a very favorable condition for mold growth. The remedy for
this rapid deterioration is simply to dry it so that it contains not more
than 5 per cent of moisture, and express the oil as soon as possible, avoid-
ing long storage in a warm, moist atmosphere.

Drying. — By comparing the various methods of copra drying, a hot-
air apparatus, either rotary or stationary, was found to be the most
efficient. It is suggested that a combination of centrifugal with hot-air
drying might prove of considerable value, provided a market could be

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obtained for the by-product, "coconut cream." Vacuum drying is not of
great value in the desiccation of coconuts for oil-making purposes.

(10) Although a pure coconut oil is not a suitable medium for a growth
of micro-organisms, one containing a sufficient amount of nutrient matter
and moisture may, under certain conditions, develop a growth of mold
which rapidly attacks the oil itself. A sample of pure oil to which had
been added 1 per cent of "latic" and 1 per cent of water increased in
acidity from 0.10 per cent to 8.G3 per cent on standing exposed to mold
action in an incubator for one week.

The very slight increase in acidity which a pure oil suffers on long
standing is probably due to simple hydrolysis by heat and moisture.

(11) Besides the production of free acid by molds and the decomposi-
tion of albumen by bacteria in moist copra and in impure oils, one other
factor enters into the deterioration of coconut oil. Many samples on
long standing develop a slight but noticeably acrid taste and odor, with-
out any marked increase in acidity. Such oils invariably give a blue
coloration with SchifFs aldehyde reagent, reduce silver nitrate in Becchi's
test for cotton-seed oil, and possess the power of liberating iodine
from potassium iodide. 24 This process is shown to be a direct oxidation
by the air and to depend largely upon the amount of surface exposed.
Other conditions favoring it are freedom from moisture and impurities,
as is shown by the fact that impure commercial oils, or those which
have been acted upon by mold, do not, as a rule, respond to tests for
peroxide and aldehyde, while the most marked development of these bodies
is noticed in the purest oils.

(12) The action of light and air on coconut oil is of relatively little
importance in comparison with the great changes produced by mold
growth, and it can be prevented in a large degree by keeping oil receptacles
as nearly full as possible, so as to reduce the amount of surface exposed.

24 Since writing the above I find that L. Legler [Pharm. Centr.-H. (1904), 45,
839] has noticed the same phenomenon in oxidized lard. As a test for active
oxygen he proposes to shake the sample with a solution of neutral lead acetate
and a few drops of ammonia. A yellow coloration, due to the formation of
hydrated lead peroxide, indicates the presence of oxygen. I have applied this test
to old coconut oils and find that, with highly oxidized samples, it gives a strong
coloration, but it is not as delicate as the simple reaction with potassium iodide.
To the presence of active oxygen Legler attributes the reduction of silver nitrate
in Becchi's test given by samples of oxidized lard entirely free from cotton-seed
oil. I have observed the same fact when applying Becchi's test to pure, but
oxidized, samples of coconut oil, but considered it more logical to attribute the
reduction to aldehyde-like bodies present in the oil, rather than to the active
oxygen.

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THE PRINCIPAL INSECTS INJURIOUS TO THE COCONUT
PALM (PART I).

By Charles S. Banks.
{From the Entomological Section, Biological Laboratory, Bureau of Science.)

Among commercially valuable trees, few are attacked by as small a
number of insect pests as the coconut (Cocos nucifera L.) ; but, on the
other hand, the destructive action of this limited number is very great.

The trunk of the coconut does not have its important conducting tissues
in or immediately under the bark, as is true of the cacao, the coffee, or
the mango. For this reason, even though the tree were completely
girdled, it would not be destroyed, as would be the case with the plants
above mentioned. On the other hand, insects attacking the growing point
would soon kill this part, after which the remainder would speedily die,
and, in fact, this result is the one which almost always is encountered.
Certain insects enter the crown and destroy it; shortly afterwards, the
leaves turn yellow, the fruits, if any are present, drop off, and the tree
eventually dies. It is therefore clear that any method which prevents
attacks of this kind will preserve the life of the tree.

This paper will treat of some of the most important of the insects
destructive to the coconut which have been identified, while those the
habits and life histories of which are known but the determination of
which has not yet been made will be a subject for further study. The
observations upon the habits and life histories have been made both in the
laboratory and in the field. I wish to take this opportunity of thanking
Mr. W. Schultze for his hearty cooperation in this work and for the
illustrations which he has furnished.

THE RHINOCEROS BEETLE.
Oryctes Rhinoceros L. (Tagalog, Vang).

This insect belongs to the family Dynastidse, or that of the giant
beetles, a group in which, from the standpoint of body weight, the largest
of the beetle tribe are found. This beetle is very common throughout
the Philippine Archipelago and in other countries of the East (Ceylon,
Java, India, etc.) wherever the coconut tree is encountered. All of the

143

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species of the genus Oryctes apparently have the same predilection for
the coconut and for similar palms. The presence of the rhinoceros beetle
is indicated by the large, irregular holes in the trunks of the trees or at
the bases of the largest petioles of the leaves of the coconut. These are
made by the adult beetles and serve as a means of entrance for other
insect pests, such as the Asiatic palm weevil, and also for the admission of
moisture, which eventually causes the trunk to rot. The beetles' attacks
are confined to the soft tissues near the top of the tree, and holes seen in
the trunk below this point date from the time when the growing apex
was here located.

No Oryctes has ever been found gnawing the hard, old wood of the
trunk of the coconut; occasionally adult beetles are found in these old
holes, which, however, are used only as a hiding place during the day.
In some of them old cocoons which were constructed when the hole was
at the crown of the tree are occasionally found, consisting of masses or
bundles of fiber. These have been preserved in situ, because of the small
size of the opening of the burrow. As time goes on, the old holes become
enlarged through various agencies, particularly through erosion and decay
caused by the entrance of water, so that these bundles of fiber finally
become exposed.

Life history and habits. — Like all other members of the family Dynas-
tidse, Oryctes is a vegetable feeder. While it frequently occurs in heaps
of decaying vegetation, the larvae appear to have the greatest liking for
the soft, growing point of the coconut, which is the location from which
new leaves, the flowers, and, subsequently, the fruit, obtain their nourish-
ment. Therefore, any injury to this part of the tree immediately results
in debilitating the whole plant and eventually in its death. The mode
of attack most generally encountered is that in which the female has
entered between the long stems or petioles of the outside leaves and those
immediately subjacent, and then has eaten a hole into the outer side of
the inner petioles, which are protected from the light by the external
leaf stems. As this beetle shuns the light, its attacks always begin
during the night, and by the following morning it will frequently have
entered so far into the burrow as to be protected from the light. It
then continues its feeding until a gallery of considerable size has been
excavated. The habit of burrowing would seem to be not solely for the
purpose of laying eggs but also in order to obtain nourishment, as nearly
all of the members of this family feed in the adult stage.

The egg. — I know of no record regarding the actual deposition of the
egg, nor have I found it in any of the burrows from which the adult has
been taken, but, by dissection of the females, the eggs have been obtained
in considerable numbers. Just before being laid they are of a dark
cream color and present a perfectly smooth texture. The microscope
reveals a very delicate reticulation or punctuation of the surface. They
are 3.5 millimeters long and 2 millimeters in diameter, being of a perfect

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broad, ellipsoidal form. The structure of the ovipositor of the beetle leads
one to infer that the egg is simply dropped by the female at any spot in
the gallery, where it adheres to the side of the latter until the larvae are
hatched. In none of the females which I dissected were there more than
seven or eight eggs of such a size as to indicate that they were about to
be laid, so that the insect probably deposits not more than two dozen
during its life. (PL I, fig. 1.)

The larva. — Length over dorsum when full grown, 112 millimeters; circum-
ference, 18 to- 20 millimeters; head, 12 millimeters long and 11 millimeters wide;
feet, 9 millimeters in length. It is a very soft, fleshy grub, the skin of which is
transversely doubled in numerous folds, so that it is very difficult to differentiate
the body segments. The skin is of a dirty, light ocher, the surface being smooth
in spots and in other parts covered with patches of very minute tubercles or
spines, which give it the appearance of shagreen. The body is covered with
numerous, very fine, golden or dull-whitish, curved hairs, which stand out nearly
at right angles to the surface. The head is of a much darker color than the
body and horny or chitinous in structure; it is hemispherical and so attached
to the body that the mouth projects forward. At each side of the head, projecting
downward and forward, is a slender, four-jointed antenna. The dark-brown,
slender, toothed mandibles, half the length of the entire head, are so placed as
to enable the insect to gnaw its way through the plant substance with great
facility. The maxilla? are rather conspicuous and are situated next to the
mandibles on the under side of the head and on each side of the very inconspicuous
lower lip or labium. The maxillary palpi are 4- jointed; those of the labrum 2-
jointed. The labrum is transversely elliptical, the sides slightly covering the
inner margins of the mandibles. The color of the labrum and that of the
clypeus (the trapezoidal portion above the upper lip) is the same as that of
the rest of the head. The mouth parts, with the exception of the tips of the
mandibles, are covered with golden bristle-like hairs, which serve as tactile sense
organs.

This grub has no eyes. The top and front of the head, therefore, present an
unbroken surface, which is somewhat shiny and covered with punctures, which
are almost confluent; it is nearly destitute of hairs or bristles. (PI. I, fig. 2.)

Each of the first 3 segments of the body posterior to the head bears a pair of
legs. The first leg joint projects downward, while the succeeding ones are
inclined outward and forward; the feet are armed with a single blunt claw
and densely covered with light-brown bristle-like hairs, more thickly placed at
the tips.

The body is curved, so that the length of the ventrum is much less than that of
the dorsum. It is folded or transversely corrugated so as to render it difficult to
distinguish the 13 segments of which it is composed, this being the easier toward
the anal extremity, where the folds are fewer.

Beginning with the first thoracic segment and excepting the second and third,
each remaining one to the eleventh bears a pair of dark-brown subcircular
spiracles or openings to the tracheal or respiratory system. These spiracles are
chitinous in structure and are composed of an outer broken ring of radiating
lines and an inner nearly circular portion, which is the true opening. They
may be opened or closed at will. Their large size and great prominence is
doubtless owing to the fact that the insect lives embedded in a mass of material
in which the supply of oxygen is limited.

The last three segments of the grub's body are nearly smooth and only sparsely
covered with hair, and in a living specimen the hinder end is semitransparent

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and contains a dark mass of material, consisting of the partly digested cellulose
fibers of the plant upon which the insect has fed. The anal opening occurs as a
transverse slit at the extremity .of the body. (PI. IV, fig. 1.)

Differences of opinion appear to have existed with reference to the
destructiveness of the grub of Oryctes. Blandford says:

They are harmless, and live in heaps of rotting vegetable matter or the
manure-like inside of decayed palm trees.

Both Mr. Schuitze and I have discovered them in large numbers in coco-
nut trees in which the "manure-like" material inside the trunks gave every
evidence of having been made by the grubs themselves. One tree, felled
in the town of Magdalena, Laguna Province, while still alive and to
casual observation fairly healthy, was found to have an inverted cone eaten
out at the crown, as shown by Plate III, fig. 1. This contained seven of
the grubs of Oryctes rhinoceros L. buried in the frass. There was a tun-
nel, 3 centimeters in diameter, extending down from the apex of the cone
for a distance of 90 centimeters through the heart of the tree, and at the
bottom of this tunnel was a full-grown grub, which to all appearances had
eaten its way to this point. Mr. Schuitze observed in Pagsanjan a tree
(PL II) 5 meters high, the whole of the interior of which had been eaten
out from its top to within a half meter of the ground, leaving a shell with
a wall from 15 to 20 centimeters in thickness. Within this, at the lower
part, was a mixture of water and decayed matter 50 centimeters deep,
indicating that the work of Oryctes and the Asiatic palm weevil, together
with infiltration from the top, had been continuing for a considerable
period of time. Within this rotting mass and at intervals up to the crown
of the tree were found the fiber cocoons of 0. rhinoceros L., while from
75 to 100 larvae of all sizes, from 5 millimeters to the full-grown grub,
were removed. The small number of weevils, the large number of Oryctes
larvae and pupae, and the general appearance of the interior of the tree
furnished conclusive proofs that the work was that of the insect in ques-
tion. Leaving these points aside and reasoning from the anatomy of the
larva alone, it is evident that it could work in the wood of coconut with
great ease, since it is in every way fitted for burrowing there. If it lives
only in manure heaps or in decaying matter, it would appear that there
would be no necessity for such well-developed and powerful mandibles,
nor would the head have to be of such hard material. It is true that these
grubs are always encountered in the presence of decayed matter, either in
the tree or in manure and other vegetable heaps, but, when found In the
tree, it is probable that the decaying material is a result and not the cause
of their presence. It is also true that we never cut into a tree until it
shows unmistakable signs of insect attack or disease, and therefore do not
see the work of the beetle at its incipiency. I have seen larvae one-quarter
grown removed from the burrows made by the adults in small coconut
trees, the leaves of which were pulled apart ; and I have also observed the

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removal of grubs with a piece of bent wire from young coconut trees,
although at the time I did not examine the hole sufficiently to note the
actual work of the larvae.

However, it is not to be doubted that these same insects find a suitable
place in heaps of decaying vegetable matter, as the grubs have been found
in such locations in all stages of growth. In connection with this ques-
tion, Father Stanton, formerly of the Manila Observatory, 1 makes the
following observations :

We have found several live pupae in a partly decayed stump of Pithecolobium
saman that had been lying on an old wood pile for months; at another time we
discovered one in a neat oval earthen cell within a broken bottle lying in a heap
of refuse near a stable; and on one occasion, in a single heap of earth and
manure, within a space of 1 cubic yard, we gathered dozens of larvae in all
stages of development from specimens 1 centimeter in length to those of 12
centimeters just about to transform to pupae together with half a dozen pupae
and as many perfect beetles with their elytra still rather soft, as though the
insects had just emerged from the pupal envelope. In this latter case, at least,
it appears quite evident that the whole cycle of the metamorphoses of the insect
took place right in this small pile of manure or very near to it. For, as many
of the larvae were very young, they could not well have migrated from the interior
of a coconut or buri palm, seeing that there was not a single one of these trees
in the whole neighborhood. It is evident then that 0. rhinoceros does sometimes
pass its whole larval and pupal existence in the midst of decayed or decaying
organic matter, and consequently that the eggs are deposited in such situations.
Whether they are also laid in the holes made by the female in the living tree
is still to be ascertained, though from the fact that the grubs are sometimes
found feeding in the heart of the tree high up near the crown it seems quite
probable.

He quotes Senor Vicente Eeyes, of Santa Cruz, Laguna, who says :

It is remarked that coconut trees with all the leaves fresh, with blossoms
and fruit all in perfect condition, and without any apparent cause, fall to the
ground as though a hurricane had cut them down. On being examined it is
found that from the roots up to the distance of a meter above the surface they
are completely hollowed out, the whole interior having been converted into a
mass of sawdust, and ensconced therein are a number of these worms, which have
entered from the roots and worked upward, little by little, eating away and
living upon the substance of the trunk itself.

In every case where I have encountered Oryctes in trees, except in
those which were completely hollow, the work evidently proceeded from
above downward. Of course, in those which were hollow, the channels
of the grubs were found along the inner surface of the shell of the tree,
but the evidence thus exhibited was not conclusive as to whether the
larvae had worked from above downward or the reverse.

Father Stanton notes the finding of the larvae, pupae, and adults of
Oryctes in manure and other decaying organic matter, but he also says
that he has not ascertained whether the eggs are laid in the holes made by

1 Phil Weather Bur., Bull, August (1903), 225.

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the adult beetles in the trees, adding that the fact that the grubs are some-
times found feeding in the heart of the tree high up near the crown
makes it seem quite probable that the eggs are laid there also. Every
evidence in my experience points to the great likelihood that they are
laid in these holes.

When a tree which is so badly infested as to give external signs of
debility is cut down, one usually finds larvre of all stages as well as pupae.
The question of the length of the life period of this insect is a difficult
one to determine, but from examinations, such as it has been possible to
make during the time the insects of coconut have been under special
observation, I am led to believe that it varies from eighteen months to
two years, according to the food conditions. These conditions are deter-
mined largely by the size of the plant and the proportional number of
insects in it.

Pupa. — The pupa of a female measures about 50 millimeters in length and
25 millimeters in width. The distance over the back from the tip of the head
to the hinder part of the body, which in the pupa is curved forward, is 65 mil-
limeters. It is of a light ocher yellow, in certain lights presenting a bright
satin sheen and in others a velvety appearance. The head, thorax, abdominal
segments above and below, and the wings and legs are all plainly visible, the
anterior apex of the pupa, at a point corresponding with the top of the head
in the adult insect, shows a small sharp knob or tubercle, which represents the
horn of the full-grown beetle. A very fine golden pubescence, covering certain
areas of the pupal body, causes its velvety appearance. The spiracles are placed
similarly to those of the larva, but are almost hidden by the folds or wrinkles
of the abdominal segments. On each side of the middle line of the back of the
abdomen, transverse slits, very much like spiracles in appearance and undoubt-
edly secondary breathing orifices, are seen. These occur between each two
abdominal segments, beginning with the first and continuing to the seventh,
inclusive. Between the seventh and eighth there is indication of their existence
in an atrophied state. (PI. IV, fig. 2.)

Cocoon. — The cocoon is composed of fibers of the coconut, wound transversely
and rather compactly woven or matted together. It sometimes measures 100
millimeters in length and 40 millimeters in diameter. When these insects live
in rotting material or manure, the cocoon consists simply of an oval excavation,
the interior being smoothed by the larva previous to its transformation. Unlike
many pupae of insects which feed in the interior of masses of material, this one
has no organs by means of which it may cut or push its way out of the cocoon
at the moment of transformation to the adult.

Adult. — The full-grown insect varies in length from 34 to 48 millimeters,
according to the sex and the amount of nourishment taken in the larval stage,
the average for the males being 44.2 millimeters and that for the females 37
millimeters. They are of a very dark-brown, somewhat lighter beneath, and
have a very glossy or shiny appearance. The most striking feature is the horn
on the fore part of the top of the head, this being much larger in the male than
in the female. The head, thorax, and. abdomen are easily distinguished. (PI. IV,
fig. 3.)

Male. — The head, with the exception of the horn, is irregular in form and
subglobose; the front is strongly emarginate or sulcate. It is small in com-
parison with the thorax and so concealed posteriorly by the thorax, into which
it fits very snugly, that it appears to be subtriangular from above. The eyes

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are black and shiny and so situated at the sides of the head as to be half con-
cealed by the anterior margin of the thorax. The anterior margin of the orbit
is extended so as almost to cut the eye into upper and lower sections. The
portion of the head at the base of the horn, which extends upward directly
from the clypeus, is very densely pilose or setose, as is also the frontal sulcus.
The occiput has an emargination at each side of the median line; into these fit
the strong tendons of the powerful muscles which move the head upward. The
antennae project from the under, outer margin of the head. They are composed
of 11 segments, the apical 3 of which are laminate; the first is swollen at the
apex, is as long as the succeeding 7 together, and is very strongly pilose, the
bristles being on its anterior, external surface (PL I, fig. 3). The ninth and
eleventh segments are also pilose at their outer margins and tips; the tenth,
lying concealed between them, is smooth and blade-like. The small, 4-jointed
maxillary palpi lie just beneath the insertion of the antennae at each side of the
labium, which is subquadrate, with the anterior surface strongly swollen. Its
lateral margins are strongly setose. The maxillae are laminate and hidden be-
tween the labium and the peculiarly shaped mandibles. They are strongly setose
on their exterior margins. The 3-jointed labial palpi lie beneath or anterior to
the maxillary palpi and are attached to the apical part of the lateral margin of
the labium.

The most peculiar feature of these insects, which has hitherto been unmen-
tioned in the literature on the habits of the adult, is the special form and
function of the mandibles. In the general description of the genus to which
this insect belongs, the statement is made that "the mandibles are prominent
and sometimes toothed externally." In the rhinoceros beetle the external tooth
of the mandible is curved upward and forward and has the form of the cutting
edge of a nonconcave gouge. These teeth, one on each side of the head, are by
their construction and that of the surrounding parts well adapted for chiseling
out the wood of the tree. (PI. I, fig. 4.)

The shape and position of the external mandibular teeth, the form of the
mentum, or chin, which is rounded and curved vertically, and which fits into a
groove having a like form, in the anterior margin of the prothorax, together with
the strong, well-attached muscles at the back of the head, prove conclusively that
the insect, instead of gnawing its way into the tree, chisels into it by an up-
and-down motion of the head, and it is my belief, for reasons to be given later,
that no part of the wood is taken into the body.

The horn of the male is 10 millimeters in length and 4 millimeters in width
at its base, tapering gradually to 1 millimeter at the tip, which in many speci-
mens appears as if worn off and repolished. It is sparsely punctured, these
punctures being fewer toward the tip.

Thorax. — The pronotum occupies about one-third of the length of the insect
on the dorsum, is roughly subcircular in general outline, narrower anteriorly,
having the margins somewhat reflexed. The anterior two-thirds shows a large,
shallow depression, the surface of which is transversely or concentrically strio-
punctate, and at the posterior margin of which are two rather inconspicuous
tubercles, almost coalescing. On each side and in the forward angle of the
pronotum there is an irregular depression, posterior to which and extending
narrowly around the posterior margin of the main depression, is another paren-
thesis-shaped one, broader anteriorly and having its surface roughly rugose. A
line of submarginal punctures extends around the pronotum. (PI. I, figs. 5
and 6.)

Elytra. — At the base, the wing covers are as wide as the thorax, the surface
at the outer basal angles being quite smooth. On each elytron are four lines,
one of which is subsutural, extending from base to apex. The external ones are
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very indistinct toward the apex. The part between these lines is coarsely punc-
tured, the punctures being regular on each side of the three external lines and
on the exterior of the subsutural ones. The triangular scutellum, between the
bases of the elytra, is smooth at its apex. There is a triangular rugose or coarsely
irrorated area at its base.

The under surface of the thorax is of a chestnut brown; it is highly polished
on the areas against which the legs move and strongly punctured on other exposed
parts, the punctures having a sparse pile of light-brown bristles.

Legs. — The femora are uniform in size and smooth, each with 1 row of setose
punctures nearer the posterior ventral margin. The tibiae are nearly similar
in shape and size, bearing externally 3 rather prominent teeth. The fore tibiae,
in addition, have an internal and external apical one. The mid and hind tibiae
have each 1 internal and 2 external apical teeth, armed with a row of smaller
secondary ones, and all are coarsely punctured. All the tarsi are of about the
same shape and size, except that the last joints of the anterior ones are slightly
longer than the others, and the first of the mid and hind tarsi are subconical
and slightly larger than the succeeding ones. All tarsal joints are setose or
spinose at their apices.

Abdomen. — The dorsal abdominal segments are hidden by the elytra; the 6
visible ventral ones are smooth, except for very sparse punctures and a subapical
row of setose punctures on each. There is a tuft of brown hairs at the anal slit.
The hinder exposed part of the abdomen is rounded, smooth, shiny, and sparsely
punctured. The elytra do not cover the last 2 dorsal segments.

The principal differences between the female and the male are that the former
is much smaller and its horn may be a mere tubercle, or, at best, not more than
one-fourth as long as that of the male. The depression on the pronotum extends
back less than halfway; the posterior lateral rugose areas are somewhat broader.
(PL I, figs. 5, 6). The last ventral abdominal segment of the female differs
from that of the male, in that in the former it is rounded and covered with bristly
hairs, while in the latter it is markedly emarginate. The ventrum of the abdo-
men of the female is rather densely covered in transverse rows with bristles,
except along the apical margins of the segments. The posterior part of the
pygidium is also densely hairy. Both sexes have on all the thoracic joints, as well
as at the articulation of the head with the thorax, a fringe of bristles closely
applied to the surface upon which the part is attached to prevent the entrance of
foreign matter between the sutures.

Method of operation of the adult. — The method of attack of the adult
insect was formerly believed to consist in its gnawing into the plant for
the purpose of feeding upon the soft tissues inside, its eggs not being laid
in the tree. This view is partly incorrect. Observation has shown that
the males make burrows, as well as the females, and it is probable that
they always accompany the latter at the time of egg-laying, retreating
from the burrow they have made to allow the female access. Dissection
demonstrates that the stomach of the insect contains no masticated fiber ;
on the contrary, it is filled with a dark, amber-colored liquid; nor are
there any fiber cells found in the excreta. The proventriculus or gizzard
of the insect is not provided with walls for grinding and the mandibles
are constructed somewhat like the parts of a cane mill through which the
sugar cane passes in expressing the juice, except that their surface is cor-
rugated, the elevations of the one fitting into the depressions of the other.

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The oesophagus is not more than 1 millimeter in diameter. The insect
begins the process of separating the fibers of the tree by means of its
chisel-like teeth. The rapidity with which a beetle can work is shown by
the fact that within half an hour it will have entered a fourth of its own
length into the plant tissue, and when once it is enabled to brace its
strong-spined legs against the walls of the burrow its progress is accel-
erated. The heart of the tree is its objective point.

On Plate V are shown successive layers of leaf petioles at the heart with the
burrow of an adult which finally reached the center. Figs. 1, 2, 3, and 4, respec-
tively, show the pieces from outside, inward.

An examination of the fibers as soon as they are cut by the beetle dem-
onstrates them to be almost dry, which renders it more probable that the
purpose for which they are taken into the mandibles is solely to extract
their juice, after which they are expelled from the mouth. Plate V, fig. 4,
shows the heart of the coconut tree with a beetle at work. The bits of
tissue which have been chiseled off can plainly be seen. In less than ten
minutes the insect had burrowed into the soft substance for a distance of
10 millimeters. Plate III, fig. 2, shows the initial work of a beetle in a
leaf petiole.

The beetles fly only at night; in the daytime they are readily found in
their burrows. Their wings are quite large and the wing muscles in the
thorax are strong and adapted for the flight of such heavy, unwieldy
insects. In the interspaces between the intestines and the reproductive
organs the abdomen is filled with air sacs and tracheae.

Extent and character of damage done, — It is rare to find a single coco-
nut tree anywhere in the Philippines which does not show one or more
evidences of attack by this beetle. It is the pest most frequently reported
by farmers and coconut growers, and in hundreds of trees which I have
personally examined large holes in the trunk, distorted leaf stems, or rag-
ged leaves demonstrate the character of its work. The insect larva or the
adult, in its work inside the tree, frequently cuts off the tip of the embryo
leaf or the tips of the leaflets on one or both sides of the midrib, so that
when the leaf finally grows it appears as if it had been trimmed with a
pair of shears or as if a triangle had been cut from one or both sides.
The fibers severed by the insect protrude from its burrow, giving the latter
a ragged appearance. During the daytime the beetles are frequently
encountered in very old holes, into which they evidently have gone for
the purpose of hiding. They have never been seen further to excavate
these old cavities. The openings which are made serve to allow rain
water to enter the tree, where it causes a most rapid decay of the interior,
and they also serve as an entrance for other insects quite as destructive
as the coconut beetle.

Distribution. — Oryctes rhinoceros L. is probably tropicopolitan, being
found in Honduras, India, Ceylon, Java, the Philippines, Celebes, Borneo

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and Sumatra, and recorded as coming from Africa. It undoubtedly
thrives well wherever the coconut is grown.

Dr. Koningsberger, of Buitenzorg, Java, says: "The well-known coco-
nut beetle 0. rhinoceros L. is one of the most terrible enemies of coconut
culture." And if this be the case in Java, where cultural methods have
been in vogue for so many years, it is probably much truer in the
Philippines.

Preventive and remedial measures. — The question of controlling the
ravages of this insect is a difficult one. It would appear that trees
growing to such a height as the coconut and having so few parts would
not be seriously afTected by a rank growth of weeds or underbrush or by a
lack of cleanliness in their surroundings, but this is certainly not the
case. It has already been stated that the larvae of the coconut beetle grow
in manure and rotting vegetable heaps and also thrive in rotten or
rotting coconut trees, their abundance appearing to be in direct ratio to
the degree of decay which the tree has attained. Mr. Schultze has taken
as many as a hundred larvae of all sizes from the decayed shell of a
coconut trunk. I have invariably found them in great abundance in
such situations. It is obvious that these sources of infection for healthy
trees must be removed. The first thing to do in coming into possession
of a coconut grove or in planting a new one is thoroughly to clean the
ground. All manure heaps, rubbish, rotting or fallen trees should be
removed and destroyed at once. The manure should be scattered where
it will serve the best purpose as a fertilizer, and in such a manner as to
make it impossible for the grubs to find lodgment in it. Eubbish heaps
and decayed trunks, if fallen, should be burned; if standing, should be
cut down and burned. The residue can easily be returned to the soil as
fertilizer.

Growers should not remove the dead leaves from their trees to such
an extent as to leave the young and still tender petioles or leaf stems
entirely exposed, thus inviting attack by the adult beetles. These leaf
stems have a thorough natural protection by being wrapped in a woven
fiber, the old stems remaining upon the tree until the new ones are fully
grown. When the living leaf stems are cut off a foot or two from their
union with the trunk, the sap running out offers an attraction to beetles
which might otherwise not attack the tree. Blanford discusses this
danger as follows : 2

"The trees should be left, as far as possible, in the natural state, and unnecessary
trimming either of fronds or of the fiber avoided. It may be necessary to tie up
the older fronds, and, if they must be removed, the stalk should be cut through
sufficiently far from the stem to leave the sheathing base intact. It may be
advisable to tar the cut stump if it is found to attract beetles. The value of
leaving the trees alone is shown by a passage in Ferguson's All about the Coco-nut
Palm, which is also quoted by Ridley: 'Scores of instances might be recorded

2 Kew Bulletin (1893), 73, 46.

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where, till the trees were come into bearing, a red beetle was never seen, but no
sooner was the land cleared and the trees trimmed than it made its appearance
and became very destructive. On one property the trimming system had been
carried on for years, till, indeed, more than one-third of the original plants
perished, before the estate was 10 years old, and they were going at the rate of
three trees weekly. The work of trimming was stopped for the reasons offered
above; the loss of the trees continued for some time afterwards, but at the end
of six months it had entirely ceased. On another property beetle men had been
employed for ten years, and trees were being constantly lost; from the day that
the beetlers were discontinued two trees perished within a month, and not another
was lost in the subsequent seven years.' And W. B. L. writes in the Tropical
Agriculturist to the same effect: 'The red beetle {Rhynchophorus ferrugineus)
can not penetrate the leaf imbrication, and, when the older ones decay in the
course of nature, the stem has become too hard for its operations. A tree here
and there may be lost from an accidental wound or from some defect in the
fitting of the leaf sheaths, but it is only where the good taste of the planter has
impelled him to trim the leaves that any serious damage has been done to a
field. All the leaves should be left on the tree till nature disposes of them at
her own time and in her own way. Nothing that can be done to a coconut tree
above ground can be anything but injurious/

"All wounds, whether made by accident or by insects, on the soft part of the
stem, leaf sheaths, or spike should be at once dressed with a dab of tar mixed
with fine sand. Holes should be probed with a "beetle spear" or hooked wire to
extract insects which may have caused them and then plugged with a tuft of
fiber or dry grass dipped in tar."

Obviously, no tree should be condemned until a careful and thorough
inspection makes it certain that it is beyond hope of recovery and that it
can bear no more fruit. It has been suggested by certain writers that a
good plan is to cut such felled trees open, leaving them on the ground to
attract beetles which would otherwise fly to the healthy trees; but I am
of the opinion that the less material of this kind there is in the orchard
the less is the liability of attack incurred by the bearing individuals. If
there are no wounds or vulnerable spots in the trees themselves, and if
nothing remains on the premises to attract this beetle and others, the
less will be the danger. The dead leaves should be allowed to fall in the
natural course of growth and care should be taken not to mutilate the
trees. However, in most instances the beetles already have invaded the
plantations and the serious problem is how to rid these places of them
and to prevent their reentrance. Of course, frequent inspections are neces-
sary, so as to detect invasions at the earliest possible moment, because,
as the coconut beetles hide in their burrows during the day, it is com-
paratively easy to destroy them if they are noticed in time. When they
are discovered, a long, hooked steel wire can be thrust into the burrow,
given a half turn to engage the insect upon its point, and then drawn
out. This operation requires some practice, as the beetle is well armored
with a smooth coat and has few projections upon the body. Dr. Konings- .
berger suggests crushing the insect and leaving it in the burrow as an
obstacle to the entrance of others; but this is not to be recommended in

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the Philippines, because the dead material would be sure to attract ants,
which in turn would draw other insects, such as white ants (anay) and
serious complications might arise. When the insect has been killed and
removed, it is essential to plug the hole with some substance which will
prevent further attacks at that point. For this purpose various substances
have been recommended, for example: tar and fine sand, plaster and
sand, clay and tar, or, in place of clay, plaster or cement. This mixture
should be forced into the holes as far as possible, because it then will act
as a deterrent to the decay caused by the entrance of moisture subsequent
to attacks of the beetle, while effectually closing an avenue of entrance
for others. Another remedy is to use a paste of Paris green and flour,
mixed with 10 or 12 gallons of water, and sprayed into the crown of the
tree. This method would offer difficulties when tall trees are to be dealt
with, owing to the impracticability of getting the spray to the right
places. The Filipinos use various remedies, such as sand and coarse
salt, which they place in the crown of the tree. They state that the sand
gets between the articulations of the head and thorax of the beetle, where
the constant friction sets up an irritation which eventually punctures the
soft tissues, after which the insect dies. This may be true. There is
a constant movement of the head and of the thorax, while the beetle is
working its way into the tree, and although the articulations are protected,
as explained above, by a fringe of closely fitting bristles, it is possible that
fine sand might enter as suggested and thus seriously handicap the beetle
in its boring operations, if not eventually killing it.

I have been assured by a gentleman who is one of the most successful
farmers in the Islands that natives on his plantation pour urine into the
crown of the affected coconut trees and that this method effectually rids
them of the pest. This is certainly not impossible.

ASIATIC PALM WEEVIL.
Rhynchophorus ferrugineus Fabr.

"It has been observed that coconut palms, the green leaves, blossoms,
and fruits of which appear in perfect condition, fall to the ground, with-
out having any signs of decay, as though struck by a hurricane. In such
instances it has been noted that (the trees) from the roots up to a meter
in height, are completely undermined, the interior pulverized like sawdust
and filled with nests of these worms, which have gained entrance through
the roots and gnawed their way upward, deriving maintenance from the
trunk." 3

The gravity of the attacks of the Asiatic palm weevil is well summed up
in the foregoing extract, for, while the condition referred to is not gen-
erally reported from all parts of the Islands, there is every reason to

8 Extract of translation of a communication from Senor Vicente P. Reyes, of
Santa Cruz, Laguna, with reference to R. ferrugineus Fabr.

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believe that in general the depredations of the beetle are no less serious in
their ultimate effects than in the cases reported from the Provinces of La-
guna and Tayabas, in which regions Sefior Keyes has seen the damage to
which he has made reference. I visited Magdalena, Province of Laguna,
which lies in a fairly productive coconut region, and have found condi-
tions closely resembling those set forth above, except that only a very
few trees has actually fallen. In most instances where this had occurred
the stumps had been cut off rather close to the ground during the previous
year, and hence we found little material at hand upon which to work.
However, we were convinced that the menace to coconut growing from
this insect is fully as serious as, if not more so than, that occasioned by
the attacks of Oryctes rhinoceros L.

This weevil enters the tree through the smallest wounds, leaving no
external trace of its work, so that all its ravages are committed where
not suspected; hence it is an extremely difficult enemy to combat.

The Asiatic palm weevil belongs to a group the members of which are,
almost without exception, destructive to vegetable substances, either
living or in the form of stored products, such as grains, beans, pease,
and nuts. The beetle under discussion is one of the largest of its kind.
The rice weevil is not more than 5 to 6 millimeters long ; the corn weevil,
Galandra oryza Linn., is slightly larger; the boll weevil, Anthonomus
grandis Boh., which is at present proving so serious a menace to cotton
growing in the United States, measures about 5 millimeters in length;
the plum curculio, Conotrachelus nenuphar Hbst., a weevil, is 6 millime-
ters long; while there is another species attacking the coconut which
measures 13 millimeters. The Asiatic palm weevil measures 35 milli-
meters in length. The form is strikingly characteristic in all individuals
of this group. The most prominent features are an oblong, oval-shaped
body and a long, slender, curved snout or bill, to which are attached the
antennae, either near the base or the tip. The colors vary from black to
light brown or red, but are usually obscure.

The larvae are legless, with a head of chitinous or horny structure,
usually darker than the body and having two strong mandibles well
adapted to gnawing the hardest vegetable substances. The Asiatic palm
weevil has never been seen to make a primary attack upon the hard
wood of the coconut; wherever it has been observed, it has utilized the
holes made by Oryctes, wounds carelessly made around the base of the
tree, or the steps cut into the sides of it by the tuba gatherers. Wherever
the hard bark is broken and the softer parts beneath exposed, excellent
places for the laying of the eggs are found and the beetle often makes a
hole 10 millimeters deep before depositing them. The character of the
hole and the tracks of the larvae after hatching are shown diagrammati-
cally in Plate VI, fig. 4. In laying their eggs in the burrows made by
Oryctes, the palm weevils undoubtedly make no appreciable hole, simply

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forcing the egg a short distance into the soft material in which the
burrow lies.

Egg. — The egg is slender, 2.4 millimeters long and O.G millimeter wide at the
middle, slightly more pointed at one end than at the other, and of a very light
ocher. The shell appears perfectly smooth and shiny, but when examined under
the microscope the surface is seen to be linely reticulated. (PL VI, figs. 1
and 1 b.)

Larva. — The larva does not vary essentially in general characteristics from the
time of hatching until it is fully developed. Full grown, it measures from 35 to 55
millimeters in length and from 18 to 22 millimeters in diameter. The greatest
diameter is slightly behind the middle. The hinder part of the body forms a
concavo-convex extension, a blunt spoon or scoop-shaped organ.

The head is from 10 to 12 millimeters long and 7.5 to 8 millimeters wide.
Seen from above, it is of a regular oval outline. It is of a dark-chestnut brown,
with a slight reddish tinge, and with a lighter median and 2 submedian narrow
stripes marking the sutures. (PI. VI, fig. 2.)

The space around the mouth parts and the latter themselves are of a dark
brown, w r ith the exception of the upper lip and clypeus, which are lighter. The
triangular portion of the head, immediately above the mouth, is transversely
rugose, w T ith a longitudinal furrow on each side of its middle. The remainder,
including the cheeks and occiput, is engraved with very shallow reticulations,
giving the appearance of a piece of alligator skin in miniature. The smooth,
dark-brown, subtriangular, rather blunt mandibles are exposed on each side of the
mouth; the upper lip, or labrum, lying between them, and reaching nearly to
their tips, is provided with numerous bristle-like hairs. The larva has no
antennse, but the maxillary and labial palpi are well developed and doubtless serve
as feelers. It has no eyes. The underlip, or labium, is subtriangular and rather
small, but quite fleshy; the palpi project conspicuously from each side of its tip.
(PI. VI, fig. 3.) It is supposed that the surface of all these organs is highly
sensitive and that the insect can tell desirable food by touch. The head shows
erect hairs placed at regular intervals, 5 on each side of the top and 3 back of
each mandible. Portions of the front of the head, and the mandibles, appear as
if having been rubbed off by friction with the substance in which the larva lives,
so that these parts have a dull, almost black or matte appearance.

The body is composed of a series of 13 rings very much folded and wrinkled,
the surface being of a smooth, velvety texture, except in certain spots, which are
decidedly shiny. On the back of the first segment appear 2 transverse, oblong
patches of a darker color than the remainder of the body, with a surface similar
to that of the head and serving as a protection to the animal in its movements in
the small galleries in which it works. There are similar lighter areas at the
sides of the first 3, or thoracic, segments, which are somewhat swollen and serve
in lieu of legs. Scattered over the entire surface are tiny, circular or irregular
shiny areas, from each of which arises a small curved bristle. On next to the
last segment of the body, dorsally situated, are also irregular shiny patches, each
with 6 bristles. The last segment has the upper surface concave, and the lower
convex; the posterior margin, which is slightly darker than the rest and smooth
and shiny, is flattened out and has four prominences, from each of which project
two rather long bristles. The spots from which they project are lighter in color.
The wrinkles of the body are nearly symmetrical. (PI. VII, fig. 1.) The body
curves downward, so that the back is very convex, while the underside is some-
what concave, except just back of the middle, where it is convex, then suddenly
tapering to the tip.

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This grub works its way forward through its burrows by a combination
of twisting and undulating motions. In this it is aided by the tubercular
enlargements on the thoracic segments. The hind end appears to offer no
help in this respect. It can enter from any opening through which the
head will pass. The bristles on the head serve as guides for the insect in
passing through holes. When placed upon a level surface, the grub moves
slightly sidewise, almost always upon its side, and can thus make fairly
rapid progress.

The breathing apparatus in R. ferrugineus Fabr. consists of only two pairs of
spiracles which are well developed, the others being almost rudimentary. Each
of the first pair is situated laterally on the first thoracic segment, and twice its
own length below the shiny, transverse, shield-like areas, and the second pair just
above the spoon-shaped excavation of the thirteenth segment of the body. The
latter two are one and one-half times as large as the first two, and their openings
are nearly vertical, diverging slightly below. The other segments of the body
show the spiracles only when examined under a strong lens; these are nonfunc-
tional, or at most only very slightly so.

The galleries of this grub run obliquely through the large swollen part
of the tree near the roots. (PI. VIII, fig. 3.) The specimen here
depicted w r as frill of grubs of all sizes and contained one or two pupae as
well. Adult beetles Avere also found in considerable numbers. The grubs
have been encountered in the crown of the tree in numbers varying from
15 to 20, where they work side by side with those of the rhinoceros beetle,
and it is very difficult to distinguish the galleries of the one from those of
the other. Plate III, fig. 1, shows a longitudinal section of the crown of
a tree which has been eaten out in the form of an inverted cone by the
larvae of the rhinoceros beetle and the palm weevil in company. Plate
VIII, fig. 3, shows the work of the w r eevil in the lower part of the tree very
near the roots, some of which are seen at the lower right-hand corner. It
will be noted that the galleries run obliquely, which shows that the grubs
work inward and upward from the outside of the tree. In this case the
eggs w r ere evidently laid in wounds in the root region, on the left, and
the grubs worked their way toward the center where the full-sized galleries
are seen.

Pupa. — When the larva of the palm weevil has attained its full size, it
ceases feeding and evacuates the alimentary canal, thus causing a shrinkage of
one-third in its size immediately before making its cocoon. This is elliptical in
outline, from 8 to 12 centimeters long and 5 to 6 millimeters in diameter, and
composed of the long tough fibers of the coconut trunk wound as shown by
Plate VII, fig. 3. It is closely woven and thick, so that the pupa is well pro-
tected against dampness. The grub sheds its skin and takes the form shown by
Plate VII, fig. 2. The pupa measures 35 to 40 millimeters in length and about
15 millimeters across its widest portion. The snout is doubled down on the
breast; the antennae, wings, and other organs of the beetle are plainly visible.
The color is a uniform pale-ocher, the tips of the knees being darker. Rugose
areas are situated on each side of the head, back of the eyes, on the upper part of
the snout, on the outer fore and hind regions of the pronotum, on the ridges of
the elytra, and on the dorsum of the abdomen. These areas are rather thickly

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set with short, sharp spines, which aid the beetle in escaping from the pupal skin
by holding the latter firmly in the cocoon. The spiracles, which on most of the
abdominal segments in the larva were nearly obsolete, are very prominent in the
pupa, a pair on each of the first G segments and a fainter one on the seventh
being visible.

Up to the present it has been impossible to ascertain the length of time
of either the larval or the pupal stage. The beetles begin their work in
the trees at practically the same time as Oryctes and the adults are found
together with those of the latter, so that the life periods in the larva and
pupa of both are probably about the same, or from 18 to 24 months.

Adult. — Rhynchophorus ferrugineus Fabr. is an extremely variable
insect, in its markings as well as in its size. Specimens have been ob-
tained of from 25 to 35 millimeters in length, while the color varies from
a true ferruginous, with certain black markings more or less regularly
placed, to almost entirely black, w r ith only traces of ferruginous. (PI.
VIII, fig. 1.)

Rhynchophorus sp.

This species is very closely related to R. ferrugineus Fabr., if not iden-
tical with it, merely varying in general color and in having a broad, fer-
ruginous, longitudinal band from the front to the hinder margin of the
thorax. (PI. VIII, fig. 2.)

The habits and the immature stages of this insect are similar to those
of R. ferrugineus Fabr. These beetles are found indiscriminately in
company on the same tree, and no differences are noted until the adults
are compared.

Preventives and remedies. — The prevention of the first attack of the
pest is essential. The adult male or female can not bore into the solid
tissue as can that of the rhinoceros beetle, because the snout is small and
the mandibles are relatively weak. For this reason the female seeks
wounds or holes of any kind in the trunk of the tree to deposit her eggs.
These wounds may have been caused by other insects, or they may be
accidental. One of the chief injuries to the trunk of the tree is that
caused by the gatherers of tuba, who make notches in it whereby they
may be enabled to climb to the top. As these notches are of considerable
size and depth, they offer excellent facilities for the beetles to enter and
hide or lay their eggs. All such mutilation of coconut trees should
certainly be prevented, even if it be necessary to construct bamboo ladders,
securely fastened to the trees, as is done in some localities. There are
frequently encountered in coconut plantations trees the bases of which
seem to have been chopped with no apparent purpose in view. Of course,
these offer an excellent opportunity for the beetles to begin their work.
A good, healthy, vigorous, uninjured coconut tree is practically invulner-
able to the attacks of the palm weevil.

If, in spite of all precautions, the weevils gain entrance to the tree,
the work of combating them is exceedingly difficult. Frequently, when

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they are in the softer, upper parts, it is possible to dig them out with a
wire hook similar to the one mentioned as effective against the rhinoceros
beetle larvae. In every case where these or other larvae are dug out of
a burrow, this should at once be filled with a substance distasteful to the
adult beetles. Great care is necessary in the work of extracting the
larvae, lest it should be carried to such an extent as to debilitate or kill
the tree. If the weevil larvae are located at or near the base of the tree,
where it is almost impossible to dig them out, the only practical method
is to stop all avenues of escape and then to remove the tree after it ceases
to bear fruit. It has been suggested that infested trees be cut down, split
lengthwise, and then left to attract beetles from the others. I am
opposed to such a procedure, because it would surely attract fully as many
insects from a distance as it would from the immediate neighborhood.
Such a method would be advisable only if the other trees were in great
danger from beetles already present in them. Plate II shows a coconut
tree very badly infested by both the rhinoceros beetle and the Asiatic
palm weevil. It will be seen that the entire interior has been eaten out
and converted into a mass of debris, in which both the cocoons and the
larvae of these insects were found in great abundance. The tree had
cased to bear, the growing point was gone, and there remained only a
circle of older leaves, kept alive by the small flow of sap in the outer shell
of the trunk. It is obvious that such a tree is a source of infection for
a large area.

THE SHOT-HOLE COCONUT WEEVIL.

This destructive weevil has been found in Laguna Province in con-
siderable numbers. I once felled a dead coconut tree, the trunk of which
was completely pitted from top to bottom by the insects' exit holes, and
Mr. Schultze found the larvae and pupae as well as the adults in a living
tree. (PI. X, figs. 1 to 5.)

Egg. — The egg has not been found. It is probably laid directly in
the hard wood in small cavities made by the female, as the grub can work
in any part of the trunk of a tree.

Larva. — The larva is a very pale-yellow, almost white grub, measuring 16.5
millimeters in length and 6 millimeters in diameter, resembling the larva of the
palm weevil, except that the hinder end of the body is evenly rounded. The head
is shiny and but slightly darker than the rest of the body, the region around the
mouth and the mouth parts appearing dark-brown. A very thin, brown median
line runs from the upper lip halfway to the back of the head. The spiracles are
very small and almost black. The surface of the body is smooth and very much
folded. A few bristle-like hairs are seen on the head. (See PI. X, fig. 1, illustra-
ting a full-grown larva.)

Pupa. — The pupa is 13.5 millimeters long and 6 millimeters in diameter and of
the same color as the larva. The surface is smooth and shiny. On the head,
thorax, and dorsum of the abdomen there may be seen a series of stout, brown
bristles arising from brownish tubercles. The tip of the abdomen has a small,
white tubercle on each side, from the point of which arises a small, black bristle.
There is little difference between the size of the tubercle and that of the bristle.

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The pupa rests in a cavity in the live wood, there being no attempt at forming a
cocoon. (See PL X, fig. 3, giving a lateral view of the pupa.)

Adult (PI. X, fig. 4.). — The adult both in form and in size appears very much
like the willow weevil, Cryptorrhynchus lapathi Linn., of the United States, except
that there are no tubercles on the thorax and wing covers. It measures 11
millimeters in length (exclusive of the bill, which normally is doubled under the
body) and is 5.5 millimeters in its greatest breadth. (PI. X, fig. 4.) It is of a
dark-reddish brown, somewhat mottled with gray on the forward part of the
thorax, which is very closely punctured. The head is globular and fits almost
entirely into a cavity in the front of the thorax, so that, when seen from above,
it has the form of a thin crescent. The eyes are black and somewhat oval, nearly
meeting on the front of the head, the space between being one-fourth the width
of the rostrum or bill. When the insect is at rest the antennae, which are
inserted on each side of the rostrum near its base, are completely hidden, being
drawn within the cavity in which the head fits. They are geniculate, the apical
part or flagellum being somewhat more than half the length of the bill, very
slender at its base, and increasing in size toward the club-shaped apex, which
has three segments very closely united. There are 12 segments in the antennae,
of which 11 are in the flagellum. (PL X, fig. 2.) The surface of the 3 apical
ones is very pilose and of a sensitive nature. The rostrum is smooth, closely
punctured, and slightly broadened at its apex. The mandibles are plainly visible,
slightly darker than the rostrum, and uniting at their apices to form a triangle.
The part immediately above the mandibles is covered with strong, light-brown
bristles, pointing toward the tip of the rostrum. The thorax bears a longitudinal
depression which is light-gray in color, owing to the scales on the surface, and
which extends nearly to the posterior margin, where the depression becomes a
ridge or carina one-sixth the length of the thorax.

The elytra reach nearly to the tip of the abdomen, are very rough, and are
traversed longitudinally by nine rows of punctures forming very deep grooves;
six of these extend to the apex of the wing covers, the others being interrupted
or running into each other. The external (ninth) row terminates before the
middle of the elytron. The posterior portion of the proplurae shows a decided
depression, into which the front legs fit on each side.

The legs are moderately long and very stout, the fore pair being nearly a half
longer than the other two. The rostrum reaches beyond the insertion of the first
pair; there is„a transverse carina of the mesosternum against which it rests. Two
spines are situated on the under sides of the femora near their apices, the smaller
nearer the apex, and those on the forelegs larger than those of the middle and
hind pairs. The tibiae are all of the same shape, each bearing a curved spine or
tooth and 3 bristles at its apex; the latter are external.

The tarsi are 4-jointed, the fourth being very small and hidden between the
pulvilli or pads. The tarsal claw is bifurcated, very long and slender. The
tarsi are covered with long, blunt, silvery- white scale-like hairs.

The exposed part of the pygidium, or hinder segment of the abdomen, is bluntly,
almost emarginately rounded; the apical half is covered with golden-brown bris-
tles lying flat. The last ventral abdominal segment is hairy apically. The beetles
appear to present no external sexual characters.

Remedies and preventives. — Doubtless these insects would be susceptible
to the same general treatment as that given to the Asiatic palm weevil,
although too little is known of their habits to be certain. They have
been found in all stages, generally in diseased trees or in those debilitated
by the attacks of other insects, and hence should not form a serious
menace.

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THE BONGA WEEVIL.
Cyrtotrachelus sp.

This weevil lives principally in the trunks of the betel palm, Areca
catechu Linn., where it does great damage, but inasmuch as it has also
been found in considerable numbers in coconut trees, it is here described
as far as its habits and appearance are concerned. In addition to the
larvae of the rhinoceros beetle and the cocoons and grubs of the palm
weevil, one frequently encounters in decaying betel palms or coconut
trees of 6 to 8 years, other smaller cocoons not more than 35 millimeters
long and 15 millimeters in diameter. (PI. VII, fig. 4.) These are com-
posed of a more finely comminuted fiber than those of the palm weevil,
and upon opening appear to contain a dwarfed example of the pupa of
the Asiatic weevil. However, this pupa differs in many respects from
that of Rhynchophorus ferruginous Fabr., and the frequent finding of
beautifully marked weevils of very small size convinces one that these
cocoons and pupae belong to the former.

Egg. — No eggs have been encountered, and attempts at confining the
adults for the deposition of eggs under conditions as nearly natural as
possible have failed.

Larva. — The full-grown larva is nearly of the same size as the preceding one.
However, in form it is more like that of the Asiatic palm weevil and is probably
somewhat closely related to it. The color is a light-ocher yellow. The head
is very much darker, and the mouth parts are dark-brown.

The length is 20 millimeters and the diameter 6 millimeters near the rear third
of the body, the form being strikingly like that of the Asiatic weevil in this
particular. The head projects forward and is smooth and shiny, with but few
hairs scattered over it.

The spiracles on the first thoracic segment are larger than any of those on the
other ones of the body, with the exception of the last abdominal segment, on
which they are well developed and placed on the posterior aspect. The apex of
the last segment is somewhat flattened and its hinder margin is prolonged into
4 rather obscure tubercles, from each of which arise 2 bristle-like hairs pointing
posteriorly and slightly downward. Certain areas on the skin of the entire body,
except the head, are rough or very minutely shagreened, single isolated hairs
arising from some of them.

The mouth is minute, but the upper and lower lips and the mandibles are well
developed, the latter being black. The palpi are prominent. As with the larvae
of Rhynchophorus ferrugineus Fabr., there are no evidences of external eyes or
ocelli. (PI. XI, fig. 1.)

Pupa.— The pupa is illustrated by fig. 3 on Plate XI. Its length is 13 millimeters
and its greatest diameter 6 millimeters. It is of a whitish-ocher color, certain of
the tubercles being a darker ocherous. On the front of the head, just above the
point where the eyes would appear in the adult, there are 2 prominent corrugated
tubercles, each with a single bristle; anterior to these are 2 smaller ones with
bristles; and on the snout or rostrum above the antennae are 2 more. On the
front margin of the thorax are 2 other tubercles, smaller than the largest on the
head; on the anterior half of the thorax toward the sides is another pair; and
near the posterior margin are 2 others slightly larger; all of these are provided

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with a single bristle. The first 6 dorsal abdominal segments are very sharply
defined and bear on each side of the middle a transverse group of 3 tubercles with
bristles; outside of these is a single one.

The spiracles are plainly seen at the latero-dorsal angle of each segment. The
pygidial segment is curved downward and at its middle there is a transverse line
of 8 tubercles with bristles, slightly separated on the median line. The apical
part of this segment has a median, transversely corrugated carina. On the
extremity of the last ventral segment, on each side, there is a concentrically
corrugated tubercle, from which 2 yellowish ochraceous bristles arise.

Each femur, on the outer part of its apex, has a single tuberculated spine,
darker than the surface. The pupae are very active when taken from their
cocoons, wriggling continuously if held in the hand.

A peculiar large, button-shaped spiracle may be seen on each side just behind
and a little below the prothoracic shield.

Adult. — This insect is graceful in form and very delicate in color. A black and
white drawing, such as fig. 4 on Plate XI, of course can not show its coloring,
which is one of its most striking features. The profile is shown by Plate XI,
fig. 6.

The length is 17 millimeters from the tip of the snout to the tip of the abdomen,
and the diameter about 4.75 millimeters. Seen from above, it measures 13 milli-
meters in length. Its color is a combination of ocher, reddish-ocher, and dark-
brown, or black, in which reddish-ocher predominates.

The head, exclusive of the snout, it globular, and smooth above and below,
with a few scattering shallow punctures at the side. Its color is reddish-ocher.
The eyes are jet-black and broadly crescent-shaped, nearly uniting at the upper
and under sides of the head; their exterior outline, when viewed directly from
in front, is almost a perfect circle. The rostrum is cylindrical and strongly
curved downward, the basal third being twice the diameter of the rest and
covered with circular light-gray spots, from each of which arises a tiny, dark-
brown tubercular spine. The apical two-thirds is smooth and finely punctured
longitudinally. The tip is slightly swollen laterally and of a darker color, as
are the mouth parts. The mandibles are black and glossy, and tridentate, the
teeth of one fitting into the interstices of the other. The narrow transverse
labrum, with the anterior margin rounded, is scarcely visible. The antennae,
apparently composed of 8 joints, of which the first is equal in length to the
others combined, are placed in short deep furrows on each side of the snout
a little less than one-fourth the distance from its base. The upper edge of this
furrow projects at its middle and somewhat overlaps the articulation of the
first antennal joint. The last joint is greatly swollen, being twice the diameter
of the preceding one, and is securiform. The length of the antennae is equal
to that of the rostrum. The third joint is chalice-shaped and one-half longer
than the second one, which is inserted on the inner apical portion of the first.
The prothorax is subconical, three-fourths as wide as the elytra, perfectly truncate
at its anterior margin, and slightly rounded posteriorly. A narrow collar extends
around its entire anterior margin, the sides of which are subparallel. The sides
of the thorax are rounded, and their surface is smooth, dull, and sparsely
punctured, the punctures toward the sides bearing small tubercles or spines.
These punctures are also found on the underpart of the pro- and mesothorax,
the metathorax, the ventral surface of the abdomen, the pygidium, the femora
and the tibiae of all the legs.

Thoracic markings occur as follows: A lancet-shaped, light-ochraceous or buff
median mark, extending from a point behind the anterior margin one-fifth the
length of the thorax, to the posterior margin ; on each side of this a wide black
line, broadening perceptibly at the posterior margin, meeting in front of the

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median mark and extending to the anterior margin; outside the black lines, on
each side, a reddish-ochraceous one, twice as broad as the median and not extending
to the anterior margin; external to these on each side, a broad pale-ochraceous
or buff line, mixed with reddish-ocher at its outer edge and running imperceptibly
into the extreme outer longitudinal black lines on the sides of the thorax. The
black lines are irrorated with buff and have buff punctures anteriorly.

The scutellum, between the bases of the elytra, is lancet-shaped, black, and
shiny.

The elytra have a ground color of reddish-ocher, with the following longitudinal
markings: A series of 9 punctured lines, 5 of which reach the apex; a buff line
on the sutural margin and a similar, although redder, space between the fourth
and fifth and the sixth and seventh punctured lines. Each space is interrupted
several times before it finally meets with the others near the apex of the elytron.
The elytra bear near the base \f and "]| and on the apical half f^\ on the left
and right, respectively. There is also a broad, black, uninterrupted band on the
external margin, confluent with a similar one on the prothorax. In the male
these black characters are more or less confluent. The apices of the wing covers
are emarginate at the suture; the pygidium is truncate, with the sides gradually
converging; the median portion of the ventral surface of the thorax and abdomen
is black and glossy, with numerous spine-bearing punctures; the posterior
margins of the meso- and metathorax are deeply notched; the fore coxae or
first leg joints are almost contiguous, the interspace having a transverse suture.
An elytron of the female is shown by Plate XT, fig. 5.

The legs are stout and moderately long; the femora are slightly swollen at
their apices; the tibia? of the middle legs are somewhat shorter than those of the
fore and hind ones, and all are longitudinally ribbed with spine-bearing tubercles
of minute size. The apices of all tibiae bear a large tooth and two stout bristles.
The 4-jointed tarsi are covered sparsely above and densely beneath with
golden-brown hairs. The bidentate claws are long and graceful. These beetles
have no constant external evidences of sex differentiation. (See PI. XI, fig. 2,
showing hind legs.)

Remedies and preventives. — The same preventive measures and reme-
dies apply in combating this insect as are recommended in the case of
the Asiatic palm weevil. The damage done by them is not by any means
so extensive as that due to the other insect, but, nevertheless, it should,
if possible, be prevented or stopped, as the tree is finally killed by the
summation of the attacks of the various insects which it harbors.

THE FOUR-SPOTTED COCONUT WEEVIL.

The length of this beetle, exclusive of the snout, is 5 millimeters, and
the width is 1.5 millimeters. It was found in the dead or decayed heart
or the undeveloped leaves of a small 3-year-old coconut tree during a
search for the rhinoceros beetle. It attacks only dead trees of a very
small size and is met with only in coconuts. In addition to the adult
beetles, the larvas and the pupae were secured in numbers. Plate IX, figs.
1 and 2, shows the exit holes of the adults and the work of the larvas in
the interior of the tree.

Egg. — The egg of this species is not known. It is probable that the beetles
deposit their eggs on the sticky sides of their galleries in the trees, though close
search failed to reveal them; but, as these places are also occupied by many

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other refuse-destroying insects and mites, it is probable that few of the shells
would remain after the young grubs had emerged. Doubtless some of the mites
feed upon the eggs themselves and in this way serve to limit the number of the
beetles.

Larva. — The larva is of about the same general shape as that of the shot-hole
coconut weevil, but it is more slender in proportion to its length. The length is
7 millimeters and the width 2.5 millimeters. The color is a pale-cream, the head
being somewhat darker and the mouth parts dark-brown. The head bears
numerous scattered, golden-brown bristles. The posterior margin of the labium
is rounded, with a sharp angle at the median line. The ventral surface of the
first thoracic segment is microscopically and densely spinose-tuberculated, as are
also certain transverse areas on the ventrum and dorsum of the middle abdominal
segments. The spiracles are extremely minute, somewhat slender, and pyriform,
with lines radiating from the central slit to the margin. The upper, posterior
surface of the last abdominal segment is slightly excavated, with 10 rather fine
bristles; it is of a golden-brown on its margin. The larva? feed in well-defined
burrows or galleries slightly isolated from each other.

Pupa. — The length of the pupa is 5.5 millimeters and the width at the middle
1.75 millimeters. It is cream-colored and in general shape like the pupa of the
shot-hole coconut weevil. Golden-brown spinose hairs are arranged as follows:
Two pairs, very small, on the rostrum above the antennae, 2 larger ones in front of
the eyes, 2 still larger ones on the top of the head back of the eyes, 8 pairs sym-
metrically on the prothorax, 7 on the meso- and metathorax, respectively, 2 on
each abdominal segment from the first to the sixth, 1 on the seventh, 1 at the base
of the pygydium, and 1 on the ventral apical margin of the last abdominal seg-
ment, pointing downward. Each femur is provided at the outer apical angle
with a single erect spinose hair. The spiracles are hardly visible.

Adult .---The general color of the beetle is dark-brown, with rufous patches.
The head is globular and strongly punctured. The eyes are black and broadly
crescent-shaped, contiguous beneath the head, but separated above by a narrow
shallow sulcus at the base of the rostrum. The rostrum is slender, subcylindrical,
slightly swollen laterally at the base above the insertion of the antennae, and
coarsely punctured, each of these punctures as well as all others upon the surface
of the body containing a single club-shaped hair or bristle. (PI. X, fig. 6.) The
mouth parts are extremely minute. The mandibles are tridentate, and when
closed are almost completely hidden within the mouth cavity. A narrow longi-
tudinal sulcus is situated on each side of the men turn, into which fit the maxillary
palpi. The antennae are 8-jointed and of the same length as the rostrum; the
first joint is slightly shorter than the other seven, the last is double the diameter
of the preceding one and its distal half is silvery-pubescent with sensitive hairs.

The thorax is truncately conical and its anterior and posterior margins straight
and parallel, the former having a narrow, smooth collar, back of which are nu-
merous setigerous pits or punctures. It is coarsely and deeply punctured, with
an indistinct rufous spot on each side. The scutellum is subtriangular and ex-
cavated at its middle. Each elytron is marked by 2 reddish-subquadrate spots,
one at the base and the other beyond the middle, and is traversed longitudinally
by 5 very finely punctured ridges or carinas. Between every 2 carinas there is
a double row of very regular, coarse, deep punctures. The apex of each elytron
is rather sharply rounded, the pygidium is subtriangular, and its sides and median
line are carinated and rather densely setose, the setse springing from fine punc-
tures. It is very easily depressed; in some specimens it forms an angle of nearly
90° with the remainder of the abdomen. The legs are stout, moderately long,
and the pairs about equidistant from each other and from the 2 extremities of
the body, roughly dividing the latter into 4 subequal sections, if the rostrum

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is excluded. The femora are swollen toward the apical angle and each has a
slight constriction beneath and just in front of the apex. Each tibia has an
apical claw and a tuft of pre-apical hairs beneath. The tarsi are all of equal
length. The legs are conspicuously shiny in comparison with the rest of the
body. Plate X, fig. 8, shows profile and fig. 7 an antenna of this beetle.

As is the case with nearly all weevils, these also feign death when
annoyed. They conceal themselves under any available object and unless
disturbed remain in one spot in their burrows for a long period. 4

Remedies and preventives. — These beetles are found only in locations
where others have preceded them and killed the trees; hence, they are
not in any sense a menace to the healthy tree. Their description has
here been given merely to call attention to all forms which may be
encountered.

4 It was hoped that the identifications of the shot-hole coconut weevil, the boriga
weevil, and four-spotted coconut weevil would be received from Washington in
time for insertion in this article, but as they have been delayed, it was thought
best to publish the paper and give the identifications later.

36540 9

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ILLUSTRATIONS.

Plate I.

Fig. 1. Egg of Oryctes rhinoceros L. ; magnified portion shown at 1 Z>.

2. Head of larva. (X 5.)

3. Antenna. (X 12.)

4. Left mandible of female:

{a) Profile and inner surface, showing condyle. (X7.)
(ft) Interior view r . (X 7.)

5. Profile of head and thorax of female. (X 1$.)

6. Profile of head and thorax of male. (X 1£.)

Plate II.

Coconut showing results of attacks of Oryctes rhinoceros L. and Rhynchophorus

ferrugineus Fabr.

Plate III.

Fig. 1. Crown of coconut, showing inverted cone, in longitudinal section, eaten
out by larvae of 0. rhinoceros and R. ferrugineus Fabr. (About one-
seventh natural size.)
2. Adult of 0. rhinoceros L. boring into petiole of coconut leaf. (One-
half natural size. )

Plate IV.

Fig. 1. Larva of Oryctes rhinoceros L.

2. Pupa of Oryctes rhinoceros L.

3. Adults, male and female, of 0. rhinoceros L. (All about natural size.)

Plate V.

Figs. 1-4. Heart of coconut showing burrow made by adult of 0. rhinoceros, and
a female beetle working at center of tree. (One-half natural size.)

Plate VI.

Fig. 1. Egg of Rhynchophorus ferrugineus Fabr.; magnified portion shown
at 1 5.

2. Head of larva of same. (X 2£.)

3. Labium of larva of same. (X 3.)

4. Diagram of work of larvae in base of coconut trunk, showing points of

entrance, as at A.

Plate VII.

Fig. 1. Larva of Rhynchophorus ferrugineus Fabr.

2. Pupa of Rhynchophorus ferrugineus Fabr.

3. Cocoon of R. ferrugineus Fabr., showing beetle partly emerged.

4. Cocoon of Cyrtotrachelus sp. (All about natural size.)

Plate VIII.

Fig. 1. Adults of R. ferrugineus Fabr. (About natural size.)

2. Adults of Rhynchophorus sp. (About natural size.) .

3. Work of larvae of R. ferrugineus Fabr. in wood of coconut near roots.

The larvae entered from the lower left.
166

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1<)7
Plate IX.

Figs. 1, 2. Work of shot-hole coconut weevil in trunk of coconut, with exit holes
of adults.

Plate X. (Drawn by W. Schultze.)

Fig. 1. Larva of shot-hole coconut weevil. (X 3.)

2. Antenna of shot-hole coconut weevil. (X 3.)

3. Pupa of shot-hole coconut weevil.

4. Adult of shot-hole coconut weevil. (X 4.)

5. Adult of shot-hole coconut weevil, profile. (X 4.)

6. Adult of four-spotted coconut weevil. (X 8.)

7. Antenna of same. (X 36.)

8. Profile of same. (X 8.)

Plate XI. (Drawn by W. Schultze.)

Fig. 1. Larva of Gyrtotrachclus sp. (X 5.)

2. Hind legs of adult Gyrtotrachclus sp, (X10.)

3. Pupa of Gyrtotrachclus sp. (X 5.)

4. Adult male of Gyrtotrachclus sp. (X 5.)

5. Elytron of female of Gyrtotrachclus sp. (X 5.)

6. Profile of male of Gyrtotrachclus sp. (X 5.)

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Banks: The Principal Insects, Etc.]

[Phil. Journ. Sci., Vol. I, No. 2.

Plate I.

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Banks: The Principal Insects, Etc.]

IPhil. Journ. Sci m Vol. I, No. 2.

Plate II.

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Banks: The Principal Insects. Kt<\

[Phil. Joikn. Scl, Vol. I, No. 2.

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[Phil. Jorisx. Sri.. Vol. I, No.

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Banks: The Principal Insects, Etc.] [Phil. Journ. Sci., Vol. I, No. 2.

Plate VI.

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Banks: Thk Principal Inskcts, Ktc]

[Phil. Jocrn. Sck, Vol. I. No.

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Hanks: Tin: I'uixmwi. Insists. Ktc]

[I'hil JontN. Sri., Vol. i % No,

PLATE VIII.

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Bank*: The Principal Insects, Etc.]

[Phil. Jocrn. Sci., Vol. I, No. 2.

PLATE IX.

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Banks: The Principal Insects, Etc.}

[Phil. Jovrn. Sci., Vol. I, No. 2.

Plate X.

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Banks: The Principal Insects, Etc.]

[Phil. Joitkn. Sci., Vol. I, No. 2.

Plate XL

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THE PRINCIPAL INSECTS ATTACKING THE COCONUT
PALM (PART II).

By Charles S. Banks.
{From the Entomological Section of the Biological Laboratory, Bureau of Science.)

Ill Part I of this paper, insects which attack the trunk and the
undeveloped leaves and flower clusters of the coconut were discussed. All
the forms which have been described belong to the Coleoptera, but there
are also certain species of Lepidoptera and Coccidae which attack the
coconut to a sufficient extent to warrant their being designated as
injurious. 1

Two forms of Lepidoptera are found upon the leaves of the coconut,
one belonging to the Ehopalocera and the other to the Heterocera; the
first is the coconut skipper, Padraona chrysozona Plotz, of the family
Hesperiidae, and the second, Thosea cinereamarginata Banks, of the
Limacodidse. While the nature of the damage done by the caterpillars
of these two forms is very similar, the insects differ entirely from each
other both in the larval and adult stage. Neither is likely to prove a
very serious menace to the life of the tree. Each attacks the leaflets after
they are practically full grown. A single caterpillar confines itself to a
single leaflet until, with the exception of the midrib, it has entirely
devoured it, whereupon it proceeds to another, and so on until the cater-
pillar has attained full growth. In the case of the coconut skipper, the
caterpillar not infrequently eats a space from the blade of the leaflet at
a point near its attachment to the main petiole, leaving the distal part
untouched. (See PI. I.)

1 The bibliography of coconut insects, appended, includes all forms known to
attack the tree, either here or in other countries, and is intended to be of further
aid to those interested in the subject from an economic standpoint.

211

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THE COCONUT SKIPPEK.

Lepidoptera.

hesperiid/e.

Padraona chrysozona Plotz.

During the months of September and October many of the leaflets of
small coconut trees of from 6 to 15 feet in height are partially destroyed.
Certain of these leaflets have their outer edges sewn together by means
of a pure-white silk which is decidedly elastic, so that the leaf may be
pulled slightly apart without tearing the fastening. Inside these folds
the light, yellowish-green caterpillar, having a chitinous head, somewhat
darker than the body and boldly marked with a very regular pattern, is
encountered.

Toward the latter part of October the semiactive pupae are found in
these "cradles," partially covered and surrounded by a snow-white
flocculent substance, which has a wax-like feel. This substance has very
much the appearance of the wax secreted by certain species of Coccidse
and is exuded from the skin pores of the caterpillar toward the end of
its larval stage. It serves as a protection for the pupa.

The coconut skipper, like nearly all Hesperiida?, flies during the very
early morning or the late afternoon and early evening hours, and hence
it is very difficult to observe its egg-laying habits.

The eggs are found upon the under side of the leaflets of the coconut
and but rarely more than one occurs upon a single leaflet. They hatch-
in from seven to eight days and the young caterpillar, after devouring
all of the eggshell except that portion in contact with the leaf surface,
at once proceeds to the edge of the leaf and begins to feed. This process
consists in cutting out an oblique swath extending toward the midrib, of
about the width of the insect's head. Frequently the caterpillar abandons
a portion of the leaf, after having fed upon it for a short time, the result
being that leaflets are encountered the margins of which are deeply
notched, as shown by Plate II, fig. 1. Under normal conditions, and after
the caterpillar has cut the leaflet to the midrib, it sews the margins
together to form its nest, feeding upon the cut edge, either toward the
apex or the base of the leaflet.

The neck of this caterpillar is much constricted, and therefore the head
has considerable freedom of motion, but in a state of repose the normal
dorso-ventral axis of the head is so inclined that it lies nearly in a plane
with tjie longitudinal axis of the body, thus causing the mouth to be
elevated and projected forward to form the extreme anterior point of
the insect (PI. II, fig. 3 A), which, in such larvae as those of Attacus atlas
Linn., and Thosea cinereamarginata Banks, is formed by the front of the
face or the occiput. The caterpillar of the latter has the head deflected
beneath the body.

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•213

Description and Life History.

Egg (PL II, fig. 2 and 2 A.) — Diameter 1.G5 millimeters, height 0.85 millimeter;
of a rather flat, oblate-spheroidal shape, yellow-glabrous when first laid, with
crimson, subcentral ring and central spot covering the micropyle, and developing
after two days. The under surface nearly flat, glabrous; upper surface minutely
punctured. It adheres strongly to the leaf surface.

The eggs of Padraona chrysozona Plotz are always laid singly upon the leaf,
thus differing from those of Erionota thrax Fabr., which may be found in groups
of from 8, to 15.

The period of incubation is from seven to eight days.

Larva (PL II, fig. 3). — Length 3.5 millimeters, width of head 1.2 millimeters;
upon emerging from the egg. At this stage the larva is of a pale, greenish-yellow,
with a black head, the size of which appears somewhat disproportionate to that of
the body. A very fine, light-grey, sparse pile covers the body, especially the
posterior segment.

The full-grown larva measures 45 millimeters in length and 4.5 millimeters in
width, the head being 3.75 millimeters in diameter. It is of a pale, ocher-green,
semi-transparent, permitting the viscera, especially the heart and the malpighian
and urinary glands, to be seen readily through the skin. The head, which is about
one-tenth the length of the entire body, is biscuit shaped or of a very flat, oblate-
spheroidal. The surface is strongly and coarsely punctured. The ecdysical
sutures are strongly marked by narrow sulci. It is of a glabrous, tawny, flesh-
color. A dark-brown line extends from the base of each mandible around the side
of the head to the occiput, where it is deflected forward, following the ecdysical
suture and being again deflected toward the side of the head, ending in a sharp
point, the lines of each side thus forming a Y on the median, dorsal aspect of the
head. The ocelli, which lie in the beginning of the dark line posterior to the
mandibles, are 6 in number on each side and of a dark-brown. The mouth parts
are dark-brown and glabrous and are surrounded by a rather coarse, porrect pile.
The anal segment is glabrous and its posterior margin is strongly rounded, with
numerous, white, curved setae projecting from it posteriorly. The legs are light
yellowish-buff with many white setae on their lower surfaces. The abdominal feet,
of which there are 10, are strongly pubescent. The spiracles, which are functional
on the 1st and 4th to the last body segments, are of a light-yellow.

Pupa (PL II, fig. 4 and 4 A). — Length 25 millimeters, width 4.5 millimeters.
The pupa is of a glabrous, dark-brown, but is frequently so covered with a
white, flocculent substance that its true color is not apparent. It is strongly
seto-pilose, especially on the anterior dorsal part of the head and thorax and on
the abdominal segments. The setae upon the thorax project anteriorily, those
upon the abdomen posteriorly. Very dark-brown rings extend around the apical
margins of the 4th, 5th, and 6th segments. The proboscis extends to the apex of
the 6th, its apical fourth being force free and traversely rugose.

A very remarkable feature of this pupa is the form assumed by the prothoracic
spiracles. They are completely protected by a reniform patch of dense setae and
are located one on each side of the posterior dorsal margin of the pronotum.
See PL II fig. 4 B.

Imago, male (PL III, fig. 1). — Length of body 15-16 millimeters, length of
fore- wing, 15.5-17.5 millimeters. Ground color, bright, yellow-ocher, with the fol-
lowing dark-brown markings or suffusions : The veins and a more or less oblit-
erated longitudinal patch along the posterior part of vein VIIj, and VII 2 , from the
base for one-half its length, in some specimens suffused with yelloW-ocher ; a
similar, somewhat wider patch from the end of the cell to a point its own length
from the outer margin. In some specimens this patch is confluent with the basal

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214

one, forming an irregular, oblique band across the disc of the wing from the base
to near the apex. Exterior to this wide patch, a yellow-ocher, irregularly rhom-
boidal spot, divided by the dark-brown vein V 2 . A broad, marginal, dark-brown
band from the costa to the posterior angle of wing, its inner margin scalloped and
its area crossed by ends of veins which show yellow-ocher ; a dark-brown suffusion
at the base of and posterior to vein IX. Cilia, black, suffused with yellow-ocher
toward the apex and yellow-ocher toward the posterior angle. The inner margin
clothed with long yellow-ochraceous hairs. The hind wings with ground color
dark violet-brown at the base, with iridescent, subcostal scales. Margin, dark-
brown; cilia, yellow-ocher. A longitudinal, yellow-ochraceous patch in the cell,
from which spring long hairs of the same color. A broad, yellow-ochraceous,
irregular patch extends across the wing from the outer third of vein III to the
middle of vein IX, which it follows to the base and margin of the wing respectively.
Posterior to the cell patch is another one of long, yellow-ochraceous hairs extend-
ing to the oblique band. A similar patch extends along the inner submarginal
area its own width from the inner margin of the wing.

The under surfaces of wings yellow-ocher; veins, marginal hair line, base and
inner margin to vein IX and submarginal series of suffused spots on fore wing,
dark-brown. On the hind wing the superior, oblique, yellow-ochraceous patch has
its margin indicated below by series of faint brown spots or irr orations. Antenn*
brown, with dark yellow-ochraceous tips and lighter scales beneath. Palpi, ster-
num, venter, legs and apical margins of abdominal segments, yellow-ocher. Apex
of abdomen dark violet-brown with yellow-ocher irrorations. Removal of the
head in both sexes reveals a patch of very broad, pearl-colored scales dorsally at
the neck. Under normal conditions these scales are completely hidden by the
hairs upon the head and thorax.

Female (PI. Ill, fig. 2). — Length of body 17.5-20 millimeters, length of wing
18.5-21 millimeters. Ground color, dark violet-brown, especially on the veins of
the wings ; iridescent in certain lights.

The bases of the fore and hind wings, the head, thorax, the abdomen dorsally
and the entire lower surface suffused with greenish-buff. Fore-wings above, with
an irregularly, sub-rhomboidal spot in the end of the cell, 2 oblique, parallel
lines between this and the costa, 3 parallel patches beyond them, near the costa
an oblique, interrupted band, from the outer third vein of V 3 to the middle of
inner margin, buff, irrorated with brownish scales. Beyond the oblique band an
irregular patch between veins III 5 and V 2 interrupted by vein V x . Inner margin
with greenish-buff hairs for two-thirds its length. Cilia brown and greenish-buff.

Hind-wings as described above, w r ith an ill-defined, interrupted, oblique, buff
band from the middle of vein V to the middle of vein IX along which it extends as
in the male. Cilia, buff. Inner submarginal area with long, greenish-buff hairs.

Beneath; wings brown, entirely suffused with greenish buff; the markings,
which are buff above, are very pale-buff below and both wings have distinct, dark-
brown veins and marginal lines.

Antennae dark-brown above, and buff beneath to the base of club; bases of
antennaj, black. Palpi, greenish-buff; apical segment, dark-ocher. Thorax and
legs covered with dark, greenish-buff scales and hairs; tarsi, with reddish-brown
spines beneath. Abdomen with 5 distinct, transverse, black lines and 3 indistinct
apical orange ones dorsally. Anal region with orange scales.

Semper 2 says of this species: "This beautiful species is very easily recognized
by the 3 yellow rings of the abdomen. It belongs next to augiades Felder and
palmarum Moore, in which the males also lack the sexual sign [discal patch],
upon the forewings, which appears in the female of augias L., and bambusce Moore.

2 Semper: Reisen auf den Philippmen (1892), 2 No. 5, 301 et seq.

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Upon this ground, I believe, Staudinger's opinion that bambusce is a variety of
augiadcs can never be right according to my way of thinking."

"The female of chrysozonu varies greatly in the width of the dark markings;
1 have some which are as dark upon the upper side of the forewings as Moore's
palmar urn, others again have, with exception of the border, only fine, black
stripes along the veins and a faint, dark shadow on the end of the cell. The
ground color is darker than in palmarum, and the same as in augiades. The
female on the upper side is exactly the same as the drawing of palmarum, but
differs on the underside in that the light bands are nearly as clearly marked as
they are above. The ground color is greenish-gray-brown. "

This species is also found upon the betel palm (Areca catechu L.) ; in
fact, Semper indicates in his note concerning this insect that the larva
is only encountered upon that tree. My observations disprove this state-
ment; indeed, it rarely is seen on any palm other than the coconut.

Preventives and remedies. — This insect is never found in sufficient
numbers to justify the fear that it may become a serious menace to
coconut culture, but as its feeding upon the leaves of small trees may
have a tendency to debilitate them, its larvae should be destroyed whenever
they are encountered.

Parasites. — This insect is probably, to a great extent, held in check by
two small Hymenopterous parasites, Chalets obscurata Walk., and an
unidentified Braconid, both of which attack the larva, laying their eggs
within its body, their young feeding upon its fats and body fluids. The
larvae of the former parasite, of which there may be as many as 10, pupate
within the pupa of the coconut skipper, which they kill, emerging there-
from in from five to six days thereafter (PI. IV, fig. 1) ; those of the
Braconid leave their host when they are full grown and, like all true
Braconidse, they spin pure-white cocoons in the vicinity of the now dead
and shriveled caterpillar. After spinning their cocoons the insects
emerge in about 4 days. (PL IV, fig. 2.)

DESCRIPTION OF PARASITE.

Walker's description of the Chalcid is as follows :

Ghalcis obscurata Walk., Proc. Ent. Soc. Lond. (1874) 399.

Male. — Body, antennae and legs black, with the usual structure. Body convex.
Head and thorax scabrous, dull. Antennae stout, nearly filiform. Prothorax
about four times as broad as long. Sutures of the parapsides, distinct. Abdo-
men smooth, shining, subsessile, with cinereous tomentum toward the tip. Femora
yellow at the tips, hind femora minutely denticulated beneath. Tibiae yellow,
striped beneath with black; hind tibiae black at the base. Tarsi yellow, tips
black. Wings cinereous; squamulae yellow; veins black; ulna about half as long
as the humerus.

Hab. : Hiogo (George Lewis), Philippines (Banks).

This is the first record of this species of the Chalcididse as from the
Philippines.

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THE COCONUT SLUG-CATERPILLAK.
Lepidopteba.

LIMACOUIDiE.

Thosea cinereamarginata Banks.
Thoxea cinereamarginata Banks, Phil. Jovrn. Sci. (1906), 1, No. 3, p. 229.

The slug-caterpillar is easily distinguished from other Lepidopterous
larvae by the form of its body and its mode of locomotion, which is more
like that of slugs or snails than of insect larva?. Several species are
known in the Philippines, many of them feeding upon palms. In
Manila, this caterpillar is quite common and is usually found feeding
either upon the upper or the lower surface of the leaves of the coconut.
It presents a rather forbidding aspect, due to its being well armed with
a double series of spinous tubercles placed upon either side, but, as a
matter of fact, unlike most Limacodidae, it possesses no poisonous
properties. I have handled the larva? freely without experiencing any
discomfort.

The damage which this insect does to the coconut leaves is about
equal to that of Padraona chrysozona Plotz.

Egg. — Diameter 1.5 millimeters, height 0.95 millimeters; of a flat, oblate-
spheroidal shape and with minute reticulations upon th.e surface, pale-ochraceous.
The larva escapes through a slit which divides the shell across its face, and the
latter is not eaten as in the case of Padraona chyspzona Plotz. The period of
incubation is from 5-7 days.

Larva (PI. V, fig. 1). — When full grown, length, 23.75 millimeters, width,
14.25 millimeters including the tubercles. It is pale-green above and pale green-
ish-yellow at the sides, being almost pure-white beneath, and with the following
markings: a median, light-purple or heliotrope band with symmetrical scalloped
margin, the scallops expanding upon the respective segments. The margin of this
band is darker purple and shades into the green of the dorsum. The band is
developed into more or less of a patch upon the fourth and seventh segments,
where the colors are darker. External to this band, on either side, is a series of
9 horizontally-projecting, spiniferous tubercles, those upon the second, fourth,
sixth, eighth, and eleventh being twice or slightly more than twice as long as the
remaining ones. Below these, ventrally on either side, is a series of 8 light-purple
spots, one on each segment from the third posteriorly, and below these another
series of 8 spots beginning upon the 4th segment. At the latero-ventral angle,
a series of 11 horizontally projecting spiniferous tubercles, one of which projects
anteriorly and another posteriorly on either side. The spines of these tubercles
interlace and are yellowish-green at their bases and purple or black at their tips.
Many of the spines have a white hair at their tips, and the shorter ones at the
bases of all tubercles have somewhat inflated tips. The head is yellow-green and
when the caterpillar is not feeding, is retracted within the 1st thoracic segment.
The length of the larval stage varies from 21-25 days.

Pupa (PI. V., figs. 2 and 2 A.) — Length 8.5 millimeters, width 5.5 millimeters.
The color is a light yellow, with ochraceous bands on the posterior margins of the
dorsal, abdominal segments; the wing pads are livid flesh-color and the eyes are
dark-gray.

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Cocoon. — Length, 8.75 millimeters; dark-brown, cocciform or oblate ovoid, com-
posed of finely comminuted leaf fiber held together with silk. The interior is
white and silk lined. The pupal stage lasts about 22 days. Time of flight, the
month of January.

Adult. — A description of the adult male and female of this species occurs in the
Phil. Jouvn. Sci. (1900) 1, No. 3 p. 229. It is quite closely related to Thosea
minima Semper, from which, according to Semper's description, it differs chiefly in
having the prominent antemedial oblique sinuate band extending from near the
cell spot to the middle of the inner margin.

Preventives and remedies. — The same methods of treatment apply to
this species as to the Coconut skipper, though, as in the case of the
other, there is no possibility of its ever becoming a serious pest.

SCALE INSECTS.

With exception of a few species from which useful or commercial prod-
ucts are obtained, such as the cochineal insect, Llaveia cacti Linn., and
the lac insect, Tachardia lacca Kerr, practically all known species of
scale insects are detrimental to man's agricultural interests. In some
parts of the world they do more damage to crops and trees than is due
to the effects of all the other insects of the region. While, in the Philip-
pines, this is not so strikingly true in the case of the coconut palm, still
the damage done to this tree by species of the family Coccidae is very
considerable. It is rare to find a coconut which does not, by its yellow
or brown leaves, indicate the ravages of these pests. Scale insects differ so
greatly from ordinary insects that they may easily escape detection. As
a rule, the commoner forms appear merely as rusty-brown or yellowish
patches upon the surfaces of the leaves, or on the bark of the stems or
trunk of the plant.

Characters. — In all species the body of the adult female is either
covered with a scale formed of a waxy secretion in w T hich the exuviae of
the earlier stages are compacted or else the body of the insect itself
assumes a form which suggests a scale or tubercle upon the host plant.
The males of all species are winged, but on account of their very minute
size and pale colors escape notice unless they are bred upon the food
plant under glass, in which case they may be captured upon emerging
as adults. The newly hatched young of both sexes are, of course, much
smaller than the adults of either sex and it is almost impossible to see
them with the naked eye.

Upon hatching, the young, coming from beneath the parent scale,
scatter upon the leaf surface in quest of a favorable place to settle.
Shortly after their ' first meal, which is obtained by inserting their
probosces into the succulent part of the leaf or twig, the insects shed
their skins, but during the period of feeding there will have exuded
from certain body pores a pale, wax-like secretion which, adhering to
the first exuviae, after a brief period assumes the form of a scale-like
covering.

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In the first molt the females usually shed their legs and sometimes
their antennae, so that a female nymph or adult appears as a mere sack,
attached to the plant by the proboscis. The female, in those species
having a distinct scale, remains under this covering throughout life,
while the male, after a succession of molts, comes forth with legs and
wings well developed.

In view of the great difference in appearance between the male and
the female, it is necessary to consider their respective characteristics
separately for purposes of classification, it being impossible to identify
two given specimens of different sex as belonging to the same species
unless they are found in close association or are bred from a given lot.
In view of the relative scarcity of males in most genera of Coccidae, the
characters found in the female form the chief basis upon which their
determination is made.

In the Philippines, so far as is known, seven species of Coccidae are
found upon the coconut. Of these, Aspidiotus destructor Sign, is by far
the most abundant and destructive; next in abundance is Chrysomph-
alus propsimus Banks, a species which has usually been encountered in
great numbers on all trees examined both in Manila and in the provinces.
The order of abundance of the remaining species is that of the following
notes :

THE TRANSPARENT SCALE.
Aspidiotus destructor Sign.

This extremely prolific scale is found on the coconut palm in all
localities in the Archipelago where investigations have been conducted.
It is extremely injurious to the trees, causing their leaves to assume a
characteristic yellow color, which is easily noted from a distance. Where
it is encountered, the under surfaces of the leaflets are covered with
thousands of small, rough, circular patches, which are almost transparent
and so thin that the insect and her eggs can be seen beneath. When the
leaflet is pulled longitudinally or when it wilts, the scales become striated
owing to the tension on the edges which are attached to the leaflet.
Plate VI, fig. 1, shows adults and young scales upon a leaflet. It will be
noted that the latter have fixed themselves to the longitudinal veins and
therefore are arranged in very regular rows. Fig. 1 A shows young
insects which have emerged from beneath the scale of the parent ; female
scales from which the occupants have been eaten by a tiny predaceous
beetle of the family Coccinellidae, are also present. Fig. 2 shows a
coconut leaflet attacked by a form of disease which causes spots, very
similar to those resulting from the attacks of Aspidiotus destructor Sign.,
to appear on the upper surface. In case of doubt as to the origin of the
spots, certainty is reached by examining the underside of the leaflet,
where, if it is attacked by scale insects, the latter will be found just at
the point of discoloration of the leaflet.

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DESCRIPTION.

Egg (PI. VII, fig. 4). — Length 0.2 millimeter, width 0.1 millimeter, regularly,
bluntly oval, one side more convex, very pale lemon yellow, smooth, laid in two
or three more or less regular concentric rows around the parent within the scale.
This regular distribution necessitates a nearly complete rotation of the female
around the point of insertion of the proboscis. This is accomplished by an undu-
lating motion of the body and may be observed by placing the live insect upon a
piece of glass, under the microscope.

Larva (PI. VII, fig. 8). — Immediately after hatching the length is 0.25 millime-
ter, the width 0.15 millimeter. Pale yellow, slightly lighter in color than egg.
Eyes dark red; antennae 5 jointed, slightly setose, last joint 3 times as long as
the first 4; transversely, microscopically striate, biapical as shown by Plate VII,
fig. 5, with a single seta from each apex; mouth two-fifths of distance from frontal
to anal margin. Anal margin dentate, giving indication in both sexes of existence
of pygidial lobes. These disappear in the male upon the second molt. Legs
moderately long, femora somewhat stout. Tarsi single jointed with 2 knobbed
spines on the dorsal margin. Proboscis about as long as the body. Four minute
hairs project from the frontal and 2 from the anal margin of body, the anal
being 4 times the length of the longest frontal.

Male puparium. — Oblong-oval, pale, translucent, larval exuviae at center slightly
darker, yellowish. Plate VII, fig. 3, shows the male puparium.

Female puparium (PI. VII, fig. 2). — Differs from male in being more nearly
circular. Color as in male. Larval exuviae at or slightly removed from the
center. Darker than the scale itself, yellowish.

Signoret's description s is very meager. It is as follows :

"The scale is round, of a transparent white, with the exuviae at the center, and
of a yellowish transparent white.

The female is yellow, round; the extremity with six lobes, of which the two
median are shortest ; the pygidium with four groups of wax- glands of eight to
ten orifices in each [group] agglomeration."

He says further concerning the insect: "This species appears to cause great
damage to coconut groves in the Island of Reunion, where they are menaced with
complete destruction. The scale is also found on palms and dates. We have found
it likewise on Goyavius psidium [Psidium guayava] which we received in the same
package."

It will be seen that Signoret's description is not sufficiently detailed to differen-
tiate this scale from other very similar ones, as he makes no mention of the
squames, their number, and arrangement, which, for example, is a very important
point in distinguishing Aspidiotus destructor Sign., from A. latanice Sign. The
following description has been prepared from fresh material:

Adult female (PI. VII, fig. 2) .—Length 0.80-0.90 millimeter, width 0.65-0.75 mil-
limeter, bright pale-yellow, broadly oval, nearly circular, narrowed posteriorly,
with slight emargination at the base of the pygidium, which is only slightly paler ;
posterior margin, whitish creamy, due to waxy secretions; two submedian white
spots on each side of the genital aperture show the position of the circumgenital
glands, the posterior of which have 4 to 5 apertures, the anterior 7 to 9. Anterior
margin of the body regularly rounded, abdominal segmentation laterally distinct.
Antennae, small, oval knobs with inwardly curving bristles at the apex, situated
one- third of the distance from the frontal margin to the rostrum. Between the

''Ann. Soc. Ent. de France (1869), (4) 9, 120; Plate XII, figs. 8 and 8a.
Translation.

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an ten nee on the ventral surface are from 5 to 10 minute spinous tubercles.
Parastigmatic glands not present. Stigmata subcylindrical. Pygidium (PI. VII,
fig. 6) with 6 lobes, median pair shorter than the next, weakly tricuspid, light-
brown, next pair bicuspid, Blightly paler, exterior pair of the same color, bicuspid,
of the same length as the median. Chitinous portions of all lobes run anteriorly
for some distance into the pygidial area, the surface of which is closely, longi-
tudinally striate. Squames as follows for each side: 2, apically fimbriated,
between the median lobes, similar ones, but more slender, between 1st and 2d
lobes, 3 stouter between 2d and 3d lobes, with fimbriation somewhat externally
laterad of apex; a series of 9 broad, laterally fimbriated ones beyond the 3d lobe
and extending one-third the distance from the latter to the base of pygidial
margin. These squames decrease in length and increase in width from the third
lobe and the number and length of their fimbriations decrease so that the last one
bears but 1 prominent spine, the remainder being reduced to sharp serrations of
its latero-apical margin. Setae placed as follows: One pair at the external base
of each median lobe nearly twice the length of latter, 1 pair between the second
lobe and its 1st external squame, 1 pair ventrad to external lobe, 1 very short,
ventrad to the 4th of the exterior 9 squames, 1 ventrad to the last squame, a small
setose tubercle near the ventral margin, two-thirds of the distance from the last
squame to the base of the pygidium. Four groups of circumgenital glands, the
posterior pair with 4 to 6 orifices, the anterior with 7 to 12. Tubular spinnerets
filiform; their heads chitinous; tube obconical, chitinous; their tongues one-third
the diameter of their heads and equal to them in length. Numerous trumpet -
shaped or subcylindrical ducts toward the apex and having orifices on the margin,
as do tubular spinnerets. Anal opening about halfway from genital orifice to
posterior apex. For details of structure see Plate VII, fig. 6.

Adult male (PI. VII, fig. 1). — Pale-yellow, with darker, pinkish-yellow, trans-
verse apodema. Head about one-tenth the length of entire body, including genital
sheath. Ocelli very dark red; upper pair slightly extra-marginal, lower pair
posterior and contiguous on median line, their diameter one-fourth greater than
upper ocelli. True eyes posterior to and their own diameter distant from the
upper ocelli, submarginal. Antennae composed of 10 joints, of which the first 2 are
subglobular, 3 to 5 subequal in length and about 3 times the length of second,
all segments sparsely setose. Tenth segment attenuated, terminating in a clubbed
hair, surrounded by 3 other curved hairs of equal length. This is shown by
Plate VII, fig. 7. Legs moderately long, posterior femora slightly stouter than
the others. The single jointed tarsi, tw*o-thirds the length of tibiae, slender,
subcorneal and moderately covered with spinous hairs. Tibiae subequal to femora,
with a very few hairs each. Claws or ungues one-fourth the length of tarsi,
their digitules two-thirds their length. Tarsal digitule as long as ungues.
Genital sheath long and tapering to a sharp point; two-sevenths of the length of
the rest of the body. Wings iridescent, hyaline, obovate; veins of about equal
length and subparallel to the respective margins. Haltere has the first joint
swollen to about one-third its length, just before the apex. Second joint of
length equal to the first; spinous and hooked at extremity. Length of wing 0.63
millimeter. This insect so nearly resembles Aspidiotus latanice Sign, that it is
very difficult to separate the two species. The chief points of difference in the
female are the number of squames external to the outer lobe, the number of orifices
in the circumgenital glands, and the relative length of the median and second lobes
of the pygidium, the median in A. destructor Sign., being shorter than the 2d
pair, while in A. lataniw Sign., they are of equal length and more markedly
tricuspid.

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Aspidiotus destructor Sign., is by far the most pernicious of the scales
which attack the coconut in the Philippines. It most frequently occurs
on young trees having from one to five years' growth, in many cases
completely covering the under surfaces of all the leaves, giving them a
characteristic yellow tinge. It is certain that it is attacked by a
Hymenopterous parasite, as female puparia have been found showing the
exit holes of the adult parasite, but as yet the latter itself has not been
discovered. A small Coccinellid beetle, Scymnus sp., is a voracious feeder
upon the transparent scale, the adults as well as the larvae of this species
frequently being encountered in considerable numbers upon coconut
leaves which are covered with the scales. A description of this insect
follows :

Scymnus sp.

Larva. — Length 1.75 millimeters, width 1.01 millimeters, exclusive of the pure-
white waxen tufts which project from the front, sides, and posterior margins of
the body as shown by Plate VIII, fig. 2. The larva of this beetle when once known
can easily be distinguished from all others which might be found among scale
insects in this region. It is extremely active, running from place to place and
greedily gnawing open the delicate scale in order to obtain the insect which lies
beneath. The body is pale yellow with a greyish tinge.

Pupa. — Length 1.25 millimeters, of a light ocher-yellow. This insect pupates
within the larval skin, as do many species of the family. In this case the skin
splits along the median dorsal line, exposing the pupa.

Adult (PI. VIII, fig. 1). — Length 1.35 millimeters, width 1 millimeter, of a
dark brown, almost black, with a light-brown discal spot on each elytron. In
some specimens this spot is sharply, in others ill, defined. The entire^ body covered
with a fine, white, pubescence. Palpi, apices of femora, tibite and tarsi, brownish
ocher. (See PI. VIII, figs. 3 and 4 for antenna and palpi.)

Habits. This beetle, the adult as well as the larva, feeds on many species of
Coccidse but has been found in greatest abundance in colonies of Aspidiotus de-
structor Sign.

Chrysomphalus propsimus Banks.

Chrysomphalus propsimus Banks, Phil. Journ. Sci. (1906), 1, No. 3, p. 230. (Pis. land II.)

This scale bears a general resemblance to C. aonidum Linn., but its
color and size, together with its apparent predilection for the coconut
palm, upon which it is always found, make its identification as a
distinct species a matter of some doubt. The scales crowd themselves
upon both surfaces of the leaves of neglected or deformed trees and
frequently as many as 4 or 5 are found overlapping each other. In
Manila they breed with great rapidity and soon cover the leaflets and
even the petioles. The same species has been encountered in great
numbers upon the betel palm (Areca catechu L.) at San Miguel de
Mayumo, Province of Bulacan. It may be distinguished from other
.scale insects which might be found upon the coconut by the decided,
shining red-orange color of the pellicles. The male scales are infre-
quently met with in comparison with those of the female. (See PL X.)

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Parlatoria greeni Banks.

Parlatoria greeni Banks, Phil. Journ. Sci. (1906), 1, No. 3, p. 231. {PL III, figs. 1 to 6.)

This delicate, though prolific, scale is frequently seen in Manila upon
young, badly cared for coconut trees. It is found upon the upper
surfaces of the leaves and because of its flat shape and gray color is
difficult to detect. While not as serious a menace as either of the
foregoing species, it merits attention because of the possibility of its
great increase if it is left unchecked.

Ghionaspis Candida Banks.
Chionaspis Candida Banks, Phil. Journ. Sci. (1906), 1, No. 3, p. 232. (PL IV, figs. 1 to 5.)

Frequently coconut trees are found the partially opened leaflets of
which are covered with small, pure-white spots, due to the scales of
another species of insect differing totally as to color and form from the
foregoing. This scale multiplies rapidly upon either surface of the
leaf, usually in the protected parts. As a rule, the female puparium
occurs near to a group of male puparia or else with a group of the
young scales in their first or second molt (PI. IX). This insect is
not as nomadic as Aspidiotus destructor Sign., therefore its opportunity
for debilitating the tree is not as great and the danger from it is not
to be feared in the same degree as from A. destructor Sign.

Lepidosaphes mcgregori Banks.
Lepidosaphes mcgregori Banks, Phil. Jour. Sci. (1906), 1, No. 3, p. 233. (Pis. V and VI.)

This scale is comparatively rare. It occurs upon both sides of the
leaves of the coconut, especially on old ones, but seems to prefer that
part of the upper surface that is near to the midrib. It is always en-
countered singly and the puparia are seldom distorted as in the case
with Chionaspis Candida Banks. Although rare, it may at any time and
under favorable conditions propagate to the extent of being injurious.
The most noteworthy features which distinguish it are the pair of white,
waxy, horn-like projections on the front of the first pellicle, the light
color of the female puparium and the regularity of its transverse striae.

Lepidosaphes unicolor Banks.
lepidosaphes unicolor Banks, Phil. Journ. Sci. (1906), 1, No. 3, p. 234. (PL VII, figs. lto7.)

This species is of nearly the same shape and size as the preceding,
being only distinguished externally by the narrower, interior margin,
the color of the puparium and the absence of the waxy horns in old
specimens. It is less frequently met with than L. mcgregori Banks
and therefore less likely to prove a menace.

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Paralecanium cocophyllw Banks.
Paralecanium cocophyllae Banks, Phil. Journ. Sci. {1906), I, No. 3, p. 235. {PU. VIII to XI.)

This insect differs from any of the foregoing in that, if a female, it
does not lie beneath a puparium but is itself its own scale. It has
easily been found upon nearly every coconut examined in Manila, and
is readily distinguished from other species by its unusual size (being
5 to 6 millimeters long and nearly as broad), and by the 2 small patches
of orange-yellow on the posterior region. It always occurs upon the
inferior surface of the leaf. The male puparia are much scarcer than
those of the female.

A peculiar characteristic of the male insect is that it comes from
beneath its scale to shed the pupal exuviae, returning after it has
completed its transformation. The length of time after the final molt
and before it seeks the female, during which the adult male remains
beneath the puparium is not known.

PREVENTIVES AND REMEDIES.

In all the work upon scale insects affecting the coconut, it has
uniformly been observed that those trees which are ill cared for or which
have become deformed by the attacks of beetles are the ones most infested
by scales. The malformed or pathologically imbricated leaves, in their
interstices, offer ideal places for the breeding of scale insects. This fact
would point to the necessity of the removal and destruction of such por-
tions at once.

Because scale insects can only migrate as wingless larvae, it would seem
that their arrest would not be difficult, and yet, when we consider that
every wind blows these larvae from leaf to leaf and from tree to tree, we
can easily see that this fact, as well as the extreme fecundity of the
insect, renders no tree entirely safe from their attacks. However, those
trees which are the healthiest and best cared for are the ones which will
best withstand these pests.

Spraying with lime-sulphur or kerosene emulsion washes might serve,
if properly applied, for the preservation of young coconut trees, but these
remedies would entirely be out of the question for full-grown ones. The
necessity is apparent for clean, systematic and regular cultural methods
for the protection of this valuable tree from scale, as well as from all
other insect pests.

INSECTS AFFECTING COPRA.

In connection with work which has been carried on in this Bureau on
coconuts, copra, and coconut oil, it has been noted that certain lots of
commercial copra, when received from the bodegas, were badly infested
by larvae, pupae, and adults of Silvanus surinamensis Linn., and Necrobia
rufipes De Geer. Both of these insects are cosmopolitan and as they

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feed upon stored products of a character similar to copra it is only
necessary to mention them in this connection.

In the case of these, and of most other injurious insect forms, preven-
tive measures are always most advisable and if care is taken in packing
and shipping the copra, receptacles into which the insects can not find
entrance being employed, their ravages will be prevented. It is difficult
to exterminate them if once they secure a lodgment in a mass of copra.
Carbon bisulphide, which might be used successfully against similar
insects in grain, would probably prove detrimental to copra owing to
its power of dissolving oil.

BIBLIOGRAPHY.

Blanford, W. F. H. Palm Weevil in British Honduras, Royal Gardens, Kew,
Bui. of Useful Information (1893), LXXIV, 27 et seq., plates 1 and 2.
Reviewed by Riley & Howard, Insect Life (1893), V, 357.
Bureau, E. Calandra palmarum, Ann. Soc. Ent. de France (1853) XXVII, 1.
Chittenden, F. H. The Principal Household Insects of the United States, U. 8.

Dept. Agr., Div. Ent. (1896), IV, n. s., 105 and 121.
Cockerell, T. D. A. Coccidae or Scale Insects, Agric. Record (1892), Dec. Re-
viewed by Riley & Howard, Insect Life (1893), V, 362.

List of Coccidse observed in Jamaica, Insect Life (1892), IV, 333.
The West Indian Rufous Scale, Ibid. (1892), IV, 381.
The Food Plants of Scale Insects, Proc. U. S. N. Museum (1896), 19,
780, Cocos nucifera L. Fifteen species of scale insects noted as occur-
ring upon the coconut.
Some Coccidse from the Philippine Islands, Proc. Davenport Acad. Sci.
(1905), X, 133.
Coconut, Enemies of. Trop. Agr. (1889-90) IX (1890-1), X et vol. seq. Notes

upon various injurious insects attacking coconut.
Coquerel, Ch. Observations entomologiques sur divers Insects Recuilles a Mad-
agascar. Sur les moeurs des Oryctes de Madagascar et sur deux especes
de Scolia qui vivent d6pens des larves de ces Oryctfcs. Ann. Soc. Ent. de
France (1855) III, 167.

Faune de Bourbon, He de la Reunion, Col6opteres, Ann. Soc. Ent. de
France (1866) VI, 334.
Curtis, J. (Ruricola) Aleurodes cocois, Gardener's Chronicle (May 2, 1846).
De Mornay, C. F. Letter on Palm-beetles to Penang Gazette and Straits Chron-
icle (Sept. 24, 1889).
Fawcett, W. Report on the Cocoa-nut Disease at Montego Bay. Bui. Bot. Dept.
Jamaica (Sept., 1891) .

Correspondence on the Cocoa-nut disease. Ibid (May, 1892).
Ferguson, A. M. & J. All about the Coconut Palm (1885).
Fernaij), Mrs. M. E. A Catalogue of the Coccictie of the World (1903).
Green, E. Ernest. Coccidw of Ceylon (1896), 95, 207, 218.
Hickey, John B. Notes on the Palm Weevil (partly reproduced from Home and

Farm, Louisville, Ky.) ; also note by editors Insect Life (1891), 4, 136.
Horn, G. H. Note on Larva of Rhynchophorus cruentatus. Trans. Am. Ent.

Soc. (1878), VII, 39.
Konigsberger, J. C. Ziekten van Rijst, Tabak, Thee en andere cultuur gewassen
die door Insecten worden veroorzaakt. Meded. uit. s'Landsplanten. van
Java (1903), LXIV, 92 (1898), XXII, 31, 33, 39, 42.

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Phillips, J. H. ; Gabb, F. E., & Bellamy, J. Report of Commissioner* appointed

by his Excellency the Governor to inquire into the destruction of the Cocoa-
palm by the Palm-Weevil, with abstract of evidence given by Planters,

Belize, British Honduras. (Jan. 18, 1889.)
Prestoe, Henry. Report on Cocoa-nut Diseases, Demcrera Times (1876,

March 16).
Ridley, H. N. Report on Destruction of Coconut Palms by Beetles, Singapore

(1889).
Riley, C. V., & Howard, L. 0. An Enemy to the Date Palm in Florida, Insect

Life (1888), I, 14.

Bark Lice on the Cocoa-nut, Ibid (1889) I, 355.
Notes on the Palm Weevil, Ibid (1891), IV, 136.
The Coconut and Guava Mealy-wing, Ibid (1893), V, 5, 314.
Russell, W. The Cocoanut Palm: Its Culture and Diseases (1876).
Short, John. A Monograph of the Cocoanut Palm or Cocos nucifera, illustrated

(1888).
SignorEt, V. Essai sur les Cochenilles, Ann. Soc. Ent. de France (1869) (4), IX,

120 and 121, PI. XII, figs. 8 and 8 A.
Simon, M. F. Report on Beetles Injurious to Coconut Trees, Straits Settlements

Government Gazette (1887, May 27). Tropical Agriculturist (1887), VII,

548.
Stanton, W. A., S. J., Notes on Insects affecting the Crops in the Philippines.

Some Insect Enemies of the Cocoanut Palm. Bui. Phil. Weather Bureau

(August, 1903), 223.
Summers, S. V. Notes on Rhynchophorus zimmermanni Sch. Can. Ent. (1873),

V, 123.
Urich, F. W. Notes on Some Insect Pests of Trinidad, B. W. Ind. Insect Life

(1894), VI, 190 et seq.
Vermont, J. M. B., and Kennedy, J. V. Report by the Select Committee of the

Legislative Council on the Coconut Trees Preservation Bill. Penang,

Straits Settlements (Dec. 23, 1889).
"W. B. L." Coconut Cultivation. Tropical Agriculturist (1884-5), IV, 1-3,

38-40, 375-376.

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ILLUSTRATIONS.

[All figures are more or less magnified; exact size is indicated in descriptions.]

Plate I.

Coconut leaf showing work of Padraona chrysozona Plotz. Note that on some of
the leaflets the apical portion of the blade has been eaten, while in others the
basal portion is represented by the midrib alone.

Plate II. Drawn by W. Schultze.

Fig. 1. Coconut leaflet showing abandoned notches made by young Inrvne of

Padraona chrysozona Plotz.

2. Egg on margin of leaf.

2 A. Profile of egg. '

3. Full-grown larva.

3 A. Profile of head.

4. Pupa.

4 A. Lateral view of pupa.

4 B. First thoracic spiracle or stigma.

Plate III. Drawn by W. Schultze.

Fig. 1. Padraona chrysozona Plotz, male.

2. Female.

Plate IV.

Fig. 1. Chalets obscurata Walk., adult.

2. Coconut leaflet with cocoons of Braconid parasitic on P. chyrsozona
Plotz together with shriveled caterpillar skin of latter.

Plate V.

Fig. 1. Thosea cinereamarginata Banks, full-grown larva.

2. Pupa.
2 A. Lateral view of pupa.

Plate VI.

Figs. 1, 1 A. Coconut leaflet with adult females and young of Aspidiotus de-
structor Sign. Note arrangement of young along veins.
2. Coconut leaflet attacked by disease causing spots similar to those
produced by A. destructor Sign.

Plate VII.

Fig. 1. Aspidiotus destructor Sign., adult male.

2. Female puparium, showing adult and eggs.

3. Male puparium.

4. Egg.

5. Antenna of larva, distal segment.

6. Pygidium of female.

7. Antenna of adult male, distal segment.

8. Young larva.

227

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228
Plate VIII. Drawn by T. Espinosa.

Fig. 1. Scymnus sp., adult.

2. Larva.

3. Antenna of adult.

4. Maxillary and labial palpi and labium.

Plate IX.

Coconut leaflet showing male and female puparia of Chionaspis Candida Banks.
Note group of male scales around female at lower right. A few male and
female scales of Chrysomphalus propsimus Banks occur also.

Plate X.

Chrysomphalus propsimus Banks. Male and female puparia on leaflet of coconut.

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Banks: The Principal Insects, etc.]

[Phil. Journ. Sci., Vol. I, No. 3.

Plate I.

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Banks : The Principal Insects, etc.]

[Phil. Jocrn. Set., Vol. I, No. 3.

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4 4 A

Plate II.

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Banks : The Principal Insects, etc.]

[Phil. Jovrn. Sci., Vol. I, No. 3.

Plate III.

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Banks : The Principal Insects, etc.]

[Phil. Journ. Sci., Vol. I, No. 3.

Plate IV.

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Banks: The Principal Insects, etc.]

[Phil. Journ. Sci., Vol. I, No. 3.

Plate V.

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Banks : The Principal Insects, etc.]

[Phil. Journ. Sci., Vol, I, No. 3.

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Banks : The Principal Insects, etc.]

[Phil. Journ. Sci., Vol. I. No. 3.

Plate VII.

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Banks : The Principal Insects, etc.]

[Phil. Journ. Sci., Vol. I, No. 3.

Plate VIII.

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Banks : The Principal Insects, etc.]

[Phil. Journ. Sci., Vol. I, No. 3.

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Banks : The Principal Insects, etc.]

[Phil. Journ. Sci., Vol. I, No. 3.

Plate X.

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■• . ■ . r ••? - * ■ -.. ' :■■■ «v ■ .. • • *• <? ... . . . * -.*V -«•• .

?r t ;

PREVIOUS PUBLICATIONS OF THE BUREAU OF GOVERNMENT
LABORATORIE8-Continued.

X'i*M

(Concluded from second page of cover.)

No. 82. 1905. — Biological Laboratory: I. Intestinal Haemorrhage as a Fatal explication
In Amoebic Dysentery and Its Association with Liver Abscess. By Richard P. Strong M D
II. The Action of Various Chemical Substances upon Cultures of Ame-baa. By J. B Thomas'
M. p., Baguio, Benguet. Biological awl Scrum laboratories : III. ihe Pathology of In-
testinal Amcebiasis. By Paul G. Woollpy, M. r>., ..nd W. E. Musgrave M D
^ N %. SS > 19 , 05 > Bi oloyical Laborai ry.— Fu.ther Observations on Fibrin Thrombosis in
the Glomerular and in Other Renal Verse'-- in BuLonic Plague. By Maximilian . crzog,

No. 34, 1905. — I. Birds from Mindoro r.nd bmal, Adjacent Islands. II. Notes on Three
Rare Luzon Birds. By Richard C. McGi go:-.

«v.»?* S , 5 > ™ 05, — L New or Noteworthy Philippine Plants, IV. II. Notes on Cuming's
Philippine Plants in the Herbarium of the Bureau of Government Laboratories III.
Hackel Notes on Philippine Grasses." IV. Ridley, "Scitimineaj Philippinensis." V.
Clarke, "Philippine Acanthaceae." By Elmer D. Merrill, Botanist.

ATo. 86, 1905. — A Hand-List of the Birds of the Philippine Islands. By Richard C
McGregor and Dean C. Worcester.

The' previous publications «.-f + he Bureau were given out as bulletins in serial number
pertaining to the entire Eureau. These publications, if they are desired, can be obtained
by applying to the librarian of the Bureau of Science, Manila, P. I., or to the Director of
the Bureau of Science, Manila, P. I.

x The first four bulletins in the ornhuological series were published by The Ethnological
Survey under the title "Bulletins of the Philippine Museum." The other^ ornithological
publications of the Government appeared as publications of the Bureau of Government
Laboratories.

S?l

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