ON THE SENSIBLE PHENOMENA OF RUMINATION. 337 
cud should pass first through the oesophagus to have the passage 
free for the new cud; in the course of which passage it is that 
the latter obtains its formation. To say that the cud is seized 
and rejected by the oesophagus is to convey false notions. There 
is in operation, in all the parts concerned, a continuity of con¬ 
traction which sets aside all notion of independent action ; which 
successive contractile force now and then becomes expended, as 
we have seen in the stoppage of the cud in the middle of the 
neck; whence it again, instead of passing upward, descends. 
We can, as we have likewise seen, should the cud remain in 
arrest, by pressure, cause its re-descent; but when once it has 
become sufficiently masticated, give what pressure we may, we 
cannot force the cud in the reverse direction, upward, towards 
the mouth. On the contrary, indeed, the moment such pressure 
is resumed, it will re-descend. 
We concur with M. Colin that the cud which is returned to 
the mouth requires being soaked in fluid to render its passage 
easy; but we do not hold with him that such fluid is furnished 
by the rumen or by the reticulum. It cannot come from the 
rumen, because fluid never exists there in any quantity. And 
as for the water within the receptacle, fluid there not only me¬ 
chanically facilitates the displacement of the alimentary matters, 
but plays a most important part in the insensible operations of 
rumination. 
A certain quantity of ingesta becomes requisite for the con¬ 
traction of the rumen; it being rendered inert either by being 
surcharged with aliment or through emptiness. While for the 
due execution of rumination is required a proportionality be¬ 
tween the aliment taken in and the aliment under rumination. 
But the food may not be in. excess within the rumen, and yet 
the organ suffer from distention, from the disengagement within 
it of a quantity of gas : while which state continues, rumination 
ceases. In a state of vacuity the rumen lacks the point d'appui 
requisite for contraction ; the same as is sometimes seen in the 
uterus in which no water is collected, stifling, as it were, the 
stimulating and provocative pains within it. The impossibility 
of rumination under vacuity of rumen seems to prove to us, 
that the abdominal muscles play but a feeble part in the act of 
rumination. We also think that the cessation of the act, after 
paralysis being effected through section of the spinal marrow 
in the dorsal region, in M. Flouren’s experiment, was occasioned 
by the weakening of the constrictive force of the adbominal pa- 
rietes, which, in the natural condition, operates as a counter¬ 
active to the weight of the viscera. 
After taking in a sufficiency of food, the animal seeks repose 
for a longer or shorter time, during which are elaborating the 
VOL. XXV. Z z 
