14 | INTRODUCTORY ESSAY. 
The sheaths in those species with non-cirriferous leaves, and usually provided 
with flagella in the upper part of the plant, are without these appendages in the 
lower portion, as it seems that the flagella appear only when the plant has acquired 
& certain degree of development, the spadices being produced still later. In many 
cases in a full grown plant one leaf sheath bears a spadix and the next one a flagellum 
and so on: in other instances, such as C. radiatus, C. pachystemonus and. C. digitatus, 
every sheath of a fertile and full-grown plant has its own spadix. 
VI.—The Leaf-8heath Flagella. 
The leaf-sheath flagella are sterile or abortive spadices arising from some of 
the leaf-sheaths at the point where normally fertile spadices are inserted. We have 
conclusive proof that the flagella are no more than incompletely developed spadices 
in the fact that we occasionally find them bearing more or less incompletely 
developed spikelets, as not infrequently happens in C. heteroideus. Martius uses the 
name “lora” for the flagella, but I have chosen the latter term as being in more 
common use and more readily intelligible. 
In very many species the spadix, and especially the female one, is prolonged 
at its apex into a long slender clawed appendix corresponding exactly to the 
apical part of a flagellum, but,we must be careful not to mistake this appendix 
for a “cirrus” which is the corresponding flagelliform prolongation of the leaf rachis. 
For notwithstanding the very great similarity of the two kinds of appendages, 
especially in the matter of their function and the identity of their armature of 
claws, the flagellum has a morphological origin which is quite distinct from that of 
the cirrus. : 
The leaf-sheath flagella of some of the.larger species are exceedingly strong 
and resistent and are sometimes of very great length; I have measured one in 
C. flagellum which was over 7 metres long. The biological function of the flagella is 
that of attaching the individual to neighbouring plants by means of the hooked 
prickles with which they are armed; consequently every Calamus provided with well- 
developed flageila is undoubtedly scandent. Those Calami that possess flagella are 
destitute of cirri at the ends of their leaves; and, on the other hand, those species 
with cirriferous leaves have no flagella, and their spadices are usually 
comparatively short, panicled and non-flagelliferous at their apices. 
N 
As a rule then cirri and flagella, being quite similarly armed with claws, are sub- 
stitute-organs which take the place of each other in the function of providing the plant with 
means of climbing, but in some species of Group XII, the sheaths have flagella, the 
spadices are flagelliferous, and even the leaves are, though usually very imperfectly, 
cirriferous ; these species seem therefore to have exerted every means in their 
power, and that to the utmost extent, to attain a climbing habit. 
The flagella, being morphologically identical with spadices and only differing in 
the absence of branches and spikelets, consist of an axial portion clothed with 
cylindric closely “sheathing spathes and, as in the fertile spadices, have the lowest 
or outermost ‘spathe larger and firmer in texture than the megea ones, and 
actually armed with straight spines. > E 
