of graminivorous and carnivorous Animals. i6g 
The food thus mixed is returned into the mouth, where it is 
masticated by the grinding teeth ; it is then con veyed into the 
third cavity, in which it would appear from the gas * let 
loose, that a decomposition takes place, and thence it is re- 
ceived into the upper portion of the fourth cavity. 
The changes which are produced on the food in the three first 
cavities are only such as are preparatory to digestion, and it is 
in the fourth alone that process is carried on. In the plicated 
portion the food is acted on by the secretion of the solvent 
glands ; and in that portion of the fourth cavity of the deer’s 
stomach small orifices are seen in the internal membrane 
leading to cavities, the size of a pin’s head, which I consider 
to be the openings of these glands, since they bear some re- 
semblance to those of other stomachs. In the lower portion 
the formation of chyle is completed. 
In birds with gizzards the food goes through very similar 
changes ; it is picked up by the bill, which in the smaller birds 
separates the husk from the seed ; it then passes into the crop, 
where it is acted on by the secretions of that cavity, after which 
it is received into the gizzard, to undergo the same change 
produced by the grinding teeth of the ruminants; the secretion 
of the solvent glands is then poured upon it, acting upon the 
nutritious part before it is spread upon the glandular structure 
at the orifice of the gizzard, in which last situation it is formed 
into chyle. 
In the whale tribe, the first cavity, although lined with 
a cuticle, has secretions peculiar to it, and therefore cor- 
responds with the first and second of the ruminants, and with 
the crops of birds with gizzards : it answers however a further 
* Mr. Davy and Mr. W. Bn an de examined this gas, and found it to be inflam- 
mable, and not to contain carbonic acid ; which establishes a difference between, 
this process, and fermentation. 
