2 INTRODOCTOET ESSAY.
Accotdm<r to tlie yiew now explained we can imagine that the hooked spine« owe
their origin to a special sensibility of the protoplasm, which at certain determinate
points where the reaction to the stimuli happened to be more effective, niduced
tho tendency to stretch towards and twine round extraneous and heterogeneous
bodies. The causes which have given origin to the hooked spines ought apparently to
belong to the class of causes which have produced the numerous other contrivances
whereby an erect plant acquires tho power to climb. This statement is, to a certain
extent, borne out by the fact that all Palms which have booked spines on the leafrachis
and on the spadices, or which have cUwed cirri at the ends of the leaves,
or have the leaf-sheath flagella similarly armed, are climbing species; whereas, when
a Palm is only aimed with straight spines it is certainly an erect one, or is
bushy and short-stemmed, like Maiiritia, Eagcissonia, Sag us, Zalacca, Oncosperma, etc.
All seandent Calami, or to speak more generally, all climbing Asiatic Palms owe
their fitness for this kind of existence to the transformation into " c l a w s " of the
short straight spines which defend certain parts of the plant; whereas species of
the American genus Demoncus and of the Afj-ican genera Eremospatha and
Ancistrop1>yllum, which also climb, are indebted for this property to the transformation
into rigid and valid hooks of the smaller and apical leaflets of their fronds.*
Among the numerous species of Calamus known to me, only one, the small
almost steniless C. pygmaev-s, found on the tops of the mouutaina of Borneo, is able
to raise itself a few feet from the ground through the surrounding shrubs by means
of the small deflexed branchlets of its filiform spadices, which act as books,
As all Calami have, without doabt, originated ia the densest tropical forests, and
as the power of attaining the summits of the trees among which they have to
struggle for air and light has been one of their most important needs, contrivances
of various kinds and different nature have been evolved for the accomplishment of
this purpose; consequently, the numerous modifications induced by this circumstance
in their organs, supply most important characters whereby it is possible to
distinguish the various species of the gonus Calamus.
The spinosity, together with slight morphological modifications in certain organs,
is the principal contrivance by which Calami cHmb. These modifications are:—
(1) the extension of the summit of the leaf-rachis into a cirrus:
(2) the extension of the main-axis of the appendix into a long filiform-clawed
appendix :
(3) the transformation of the spadices into long whip-like clawed organs.
With the help of these characters it is not difBcult to bring the greater part of
t h e species of Calamus together into more or less natural groups.
The spathes also afford important charactcrs that can be made use of in
classifying the species of Calamus, though to a less degree than in the case of
Daemonorops, a genus in which the chief function of the spathes is to protect the
flowers, whereas in Calamus the spathes also often to a certain extent assist the
plant to climb.
• O w i o g to the peculiar arrangemsDt which preTaila in the Botanical Museum of Florence, where the library
has be«n pl.ced some kUometres away from the herbirinm, I hare not o£ late had any opportoaiiy of consulting;
the paper, by F. O. Bower, on th« modes of climbing in the genns Calamu, (Annah of Botany, vol. I, p. 126).
BIOLOGICAL AND GENERAL NOTES. 3
The spinosity, length and seandent nature of the stem, and the unwieldy size of
t h e leaved and spadices of many Calami are causes of much annoyance, labour and loss
of time to the botanist who is obliged to collect specimens of such plants. On the
other hand, this study has been greatly hindered by the very incomplete and
fragmentary manner in which, on account of these difficulties in collecting them, the
species as a rule are represented in herbaria.
Another not uncommon cause of error has been the differences that exist between
the spadices of the two sexes, to say nothing of the association, which has frequently
taken place in herbaria, of the leaves of one species with the spadices of another.
Moreover, not a few species have been based on specimens belonging to only one
sex, or on portions of but a single plant, and it has seldom happened that tho
description of a species has been baaed on the inspection of a good and large suite
of specimens taken from many individuals. If indeed we had been content to
describe only those species of which we possessed complete specimens, that is to say
entire full-grown leaves, male and female spadix and fruit, the number of those
secured to science would have been fpr smaller than it now is. Owing to the
fragmentary nature of the material available for the study of these Calami it has
been necessary to give a very rigorous, minute and full description of the various
parts of the specimens actually at hand. These often have belonged to but one
individual; consequently the descriptions now offered, like those of other authors, are
not only in many instances lacking in completeness, but frequently fail to give all
the characters essential to the collectivity of individuals that constitutes a species.
They only indicate the peculiarities of a single member of such a collectivity, or to
be more precise those of only a small portion of some of its organs. I am led to
make this remark because in more than one instance it may happen that the specific
characters which I have assigned to a species will prove inconstant, or, when
larger and more complete specimens becomo available, even be found to be not
altogether exact.
I t is indeed impossible, when we have only one half or a fragment of a leaf
available for study, to form a precise idea of the degree of variability or of the
extent and amplitude of the characters of the leaves of a given species. When, for
example, the statement is made that the leaf of a particular species has a petiole
10 cm. long, with three paii'S of leaflets on each side of the rachis, it is not meant
by this that in every leaf of the numerous individuals which constitute the species
the petiole must always be of that length and the leaflets always be exactly of this
number. The phytographer, when he has not sufficient material at his disposal, is of
necessity compelled to describe the individual. On the other hand, the student who
tries to recognize a species from a description made under such circumstances will
be careful to give no more than their due importance to the characters assigned
by the author and will make sufficient allowance for variability.
l u the case of Calami, as in that of many other Palms of large size, tho
conditions are not as they are in the case of small plants whereof a considerable
number of specimens from different places may be brought together for comparison
in the herbarium, so that the student is enabled to acquire a complete knowledge
of the degree of variability exhibited by the individuals which constitute a species.
From what has been said as regards the very fragmentary condition of the materia}
ANH. EOY. B o a ' . GARD. CALCUTTA VOL.- X I .