CHAP. 11. 
CUTICLE. 
57 
water. Its usual character is that of a dehcate membrane, 
but in some plants it is so hard as almost to resist the blade 
of a knife, as in the pseudo-bulbs of certain Orchideous plants. 
The most usual form of its reticulations is the hexagonal 
(Plate III. fig. 11.) : sometimes they are exceedingly uncer- 
tain in figure; often prismatical; and not unfrequently bounded 
by sinuous lines, so irregular in their direction as to give the 
meshes no determinate figure (fig. 5.). 
Botanists are not entirely agreed upon the exact nature of 
the cuticle ; while the greater number incline to the opinion 
that it is an external layer of cellular tissue in a dry and 
compressed state; others, among whom are included both 
Kieser and Amici, consider it a membrane of a peculiar na- 
ture, transversed by veins, or vasa lymphatica. 
By the latter it is contended, that the sinuous direction of 
the lines in many cuticles is incompatible with the idea of any 
thing formed by the adhesion of cellular tissue ; that when it 
is once removed, the subjacent tissue dies, and does not be- 
come cuticle in its turn, and that it may often be torn up 
readily without laceration. 
On the other hand, it is replied, that the reticulations of 
the cuticle are mostly of some figure analogous to that of cel- 
lular tissue, and that the sinuous meshes themselves are not so 
different as to be incompatible with the idea of a membrane 
formed of adhering bladders. We are accustomed to see so 
much variety in the mere form of all parts of plants, that an 
anomalous configuration in cellular tissue should not surprise 
us. The lines, or supposed lymphatic vessels, are nothing 
more than the united sides of the bladders, and are altogether 
the same as are presented to the eye by any section of a mass 
of cellular substance. It is certain that the cuticle cannot be 
removed without lacerating the subjacent tissue, with however 
much facility it may be sometimes separable : on the under 
surface of the leaf of the Box, for instance, there has plainly 
been some tearing of the tissue, before the cuticle acquired the 
loose state in which it is finally found. If the subjacent epi- 
dermis never becomes cuticle when the latter is removed, this 
is no reason why the cuticle itself should not be composed of 
cellular tissue; for it is an axiom in vegetable physiology, that 
D 3 
