Digestive Organs of the Ox and Sheep. 
39 
pillars of the canal," then prepared food, as soft mashes, &c., 
ought when Jirst swallowed to enter the omasum, and fluids would 
also take the same course, whereas we have many proofs, afforded 
by experiments, that these find their way into the first and second 
stomachs. Besides which, the pillars do not form " the ^oor of 
the cesophageal canal,"* as stated by Mr. Youatt and others, 
but the sides of the channel : and //' thei/ are placed in contact, 
then there is no passage or duct behind them : in short, the errors 
of description have arisen from studying these structures on the 
dissecting-table alone, and not in their natural situation. Our 
opinion of rumination receives further confirmation from the 
fact that many ruminants, of which the camel is an example, 
do not possess a reticulum ; therefore in such animals the rumen 
must propel the ingesta upwards. We could advance many 
other facts to negative the general belief, but it is unnecessary to 
do so on this occasion. It may be asked, what function we ascribe 
to the reticulum? We answer, that it supplies the third stomach 
with aliment suited for digestion ; this it receives from the 
rumen by the ordinary peristaltic action that is continually going 
on in that viscus, and passes it at intervals through the aperture 
situated at the inferior part of the oesophageal canal. (See i, fig. 5.) 
And we are further of opinion, that the before-mentioned pillars 
perform an office analogous to a sphincter, by drawing the opening 
which communicates with the omasum towards the oesophagus, 
and thus close it against any coarse or indigestible matter that is 
presented by the reticulum. 
The omasum is situated to the right of the paunch, and is the 
medium of communication between the second and the true 
digestive stomach. Its ordinary name, manyfolds, is given to it 
from the lining membrane being plicated. The plaits vary in 
length, and follow no definite arrangement with reference to the 
dimensions of those which are placed side by side : their number 
also differs in different animals; from 80 to 100 are usually found 
in the ox, but rarely more than 50 in the sheep. At the entrance 
next to the reticulum they spring from, or are condensed into, 
six or eight prominent ridges, which evidently divide the current 
of softened ingesta as it flows from that viscus, and thus disperse 
it between the multiplied folds. 
The function of the omasum has been compared to the gizzard 
of the fowl, but improperly so in our opinion, for its muscular 
coat is so slightly developed that it is impossible for it to exert any 
triturating effect on the aliment ; and the altered and varied con- 
dition of the contents of the stomach, as we believe, depends en- 
tirely on the amount of fluid secreted by it. A reference to 
* Cattle, p. 427. 
