4 INTRODUCTORY ESSAY. 
now available for the study of Calami, it will be realized that, very often, even 
the most essential characters of a species have been derived from small portions 
of a single plant, which have accordingly had to be described with great precision 
because we cannot predict which of those characters are constant and which are 
variable. The fragmentary state of herbarium specimens of Calamus is, moreover, 
often a great hindrance in the grouping of species according to their natural 
affinities, and this task has more than once to be accomplished by the author as 
the result of a mental reconstruction of the entire plant from the few fragments that 
are available to him for study. 
The incompleteness of the specimens of Calami, the difference between the 
male and female spadices, or between the flowers and the fruit, and in particular 
the not infrequent fact that the spadices in herbaria are not from the same plant 
as the associated leaves, have Jed even the most experienced botanists to propose a 
few non-existent species: nor am I certain that the present work is entirely free 
from the same blemish. | 
II.—Spinosity. 
The nature of the spinosity on the different organs of the Calami is of great 
diagnostic importance, We know of no quite spineless Calamus and even 
C. Meyenianus, which usually has unarmed leaf-sheaths and leaves, now and then 
bears a few prickles on the spadices. 
In every case the spinosity of Calimus is due to an hypertrophic growth of 
the peripheral tissues of the plant. I know of only one exception to this rule, in 
C. javensis var. acicularis (PLATE 41), which bears on the petiolar part of the leaf 
a few spinescent organs analogous to the long hooks that occur on the prolonga- 
tion of the leafrachis in the African palms of the genera Ancistrophyllum and 
Eremospatha and in the American genus Desmoncus. The spinescent hooks which 
provide the Palms of the genera mentioned with the means of climbing are 
obviously quite different as regards origin from the hooked thorns of a Calamus, 
and are no more than transformed and abortive leaflets; of this nature also I 
take the spines at the base of the petiole of C. javensis var. acicularis to Ve. 
The spines of Calamus are to be differentiated into those that serve for 
defence and those that help the plant to climb. Spines of the former category are 
long and straight, and it is to indicate these that in the descriptions of species I 
have restricted the proper name of “spines.” They are essentially organs of defence, 
to be found especially on the leaf-sheaths, at the bases of the petioles, and 
sometimes also on the leaf-rachis and on the primary spathes. When these true 
straight spines are shorter and broad-based they are more particularly termed 
‘‘ prickles” Spines of very small size, or “spinules,” are besides produced on the 
main nerves or “cost” of the leaflets and on their margins ; 
( from these we 
gradually to rigid or criniform ‘‘hairs” and to “ bristles.” = 
. The spines which subserve the function of fixin 
and so enabling it to climb, are short with a broad 
sharp tip so that they resemble the hooked nails of 
g the plant to adjacent trees, 
base, and have a curved very 
a cat; these in the descriptive 
