The Digestive System 159 
fixed in the usual fluids, the epithelial structures 
from this animal were not as clearly defined in 
most cases as could be desired; this rather 
unsatisfactory fixation may have been due to 
some physiological condition characteristic of 
the period of hibernation. That this was the 
case seems likely from the better fixation obtained 
by the same methods in the case of animals killed 
during the feeding season. 
The other animals from which tissues were taken 
were considerably smaller than the one mentioned 
above. They were killed early in the fall, after 
having been fed regularly for about five months 
upon bits of meat, both raw and cooked. 
The Tongue. The covering of the tongue was 
studied in two regions, near the free end, and 
towards the base. 
A section of the former region, drawn under high 
power, is shown in Figure 36. It consists of a 
dense mass of fibrous tissue, a, and small scattered 
cells, overlaid by a stratified epithelium of eight 
or ten layers. Only a small part of the fibrous 
base, just beneath the epithelium, is here shown. 
It is a dense areolar tissue with the elastic fibers 
apparently predominating. 
The epithelium, e, consists, as has just been 
said, of about eight or ten layers of cells, those at 
the base being generally cuboidal in shape, while 
towards the surface the cells become more and 
more flattened until at the surface they form 
