ON THE SENSIBLE PHENOMENA OF RUMINATION. 335 
the exclusive provender of the bovine race. Their food is 
either dry, or very dry, or green, or pulpous, or mealy, or liquid, 
all which variations M. Colin’s calculation has left out of con¬ 
sideration. And besides, were his estimate true, that an ox 
required more than a quarter of the day for the operation of 
rumination, he could no longer be employed as a substitute for 
the horse in certain mountainous countries where the latter is 
unavailable. But the fact is, that the ox’s food is not often 
hay alone. 
The author (M. Colin) confirms the fact of the aliments, after 
detention in the rumen being known to become acid , though, 
after return into the mouth and mastication for some seconds, 
they evince alkaline reaction ; turmeric paper recovering its 
blue but very tardily. 
Mastication being the most tangible act of the operation of 
rumination, we are enabled concerning it to speak with more 
confidence. M. Colin has used the word merycique to denote 
this process. The more simple treatment of the subject, how¬ 
ever, appears to be to consider mastication as preparatory and 
ruminatory. 
M. Colin has divided rumination into unilateral and its 
varieties, and alternate and its varieties. In this, however, he 
appears to commit a grand mistake. There may be such dis¬ 
tinctions made in mastication, though we would rather call 
them preparatory and ruminatory, and say the grand act of ru¬ 
mination is an intermediate process. To make rumination con¬ 
sist in the action of the jaws is to confound the accessory with 
the principal act, the sensible operations with the insensible 
ones. Therefore, instead of saying unilateral and alternate 
rumination, we would say unilateral and alternate MASTI¬ 
CATION. 
As to unilateral mastication, the jaw, like other parts of the 
body, is not symmetrical in its operation; its action, owing to 
various causes, may be more energetic on one side than on the 
other. Nor need we say that mastication will be prolonged by 
certain kinds of food, by age, &c., or that it will be compara¬ 
tively tardy or rapid at one time to what it is at another, owing 
to similar obvious causes. It may likewise be interrupted by 
any thing alarming the animal or provoking his attention during 
the act; and whenever he finds it impossible to continue 
mastication, with an effort he swallows the cud. We have seen 
the cud re-ascend into the gullet, and no sooner become lodged 
there than re-descend again into the stomach; as though the 
contractile force which had caused its ascent so far had become 
expended at that spot. And we have re-produced the same 
phenomenon by counteracting, by vigorously seizing hold of 
