466 Mr. Moncaw on the Anatomy 
guishing characters are more strongly marked than in most 
other species of the rodent animals. | 
The stomach is formed by a single membranous bag (Tas. 
XXVII. Fig. 1.), and as inthe case of other mammiferous vege- 
table feeders, in which we find this simple form of stomach, it 
will be seen by reference to the plate (Tas. XXVII. Fig. 2.) that 
the cæcum is large and complicated in proportion. 
Having met with nothing requiring particular notice in the 
remaining part of the alimentary canal, I proceeded to examine 
more particularly the structure of the mouth and throat. The 
grinding surfaces of the molar teeth are of very considerable 
extent, as will beseen in Tas. XXVIII. ; and it must be obvious 
how necessary such an arrangement of parts must be to the 
health of the animal, when we consider the nature of its food, and 
the simple structure and limited functions of its most important 
digestive organ, a provision being thus made for the proper 
mastication of the hard vegetable substances upon which the 
animal must occasionally subsist. I found however, upon further 
examination, that there was another structure hitherto unde- 
scribed, by which the process of perfect mastication is rendered 
indispensable to the passage of food from the mouth to the 
stomach. The structure to which I allude, and by which the 
possibility of swallowing any portion of unmasticated nutriment 
is prevented, was shown in an extraordinary formation of the 
velum palati mollis, or soft palate: this membrane, which in ` 
other animals generally forms an imperfect floating septum, 
suspended from the back part of the roof of the palate, and 
interposed between the cavity of the mouth and pharynx, I 
found in the Capybara (and in some of its congeners) to be 
much more extensive in its attachments and different in its form 
and uses. ! : 
On separating the jaws and examining the fauces, the mouth 
I appears 
P 
