EXPERIMENTS ON DIGESTION. 
437 
The oesophagus is distinguished by two layers of muscular fibres, 
which wind spirally round this tube in opposite directions, crossing 
but not interlacing with each other. 
The Prehension of the Food. — As long as the young ruminant — 
the calf and the lamb — is nourished only by the milk of the mo- 
ther, this liquid passes directly into the third and fourth stomachs, 
through the oesophagean canal. It does not, however, remain in 
the third stomach, or enter in the least degree between its leaves, 
but goes at once into the abomasum. The two first stomachs are, 
at this time, empty, and contracted upon each other. When these 
little ones begin to eat grass and hay, without altogether ceasing 
to suck, the new food is carried into the paunch and the reticulum. 
When the adult animal feeds, he contents himself with very 
slightly crushing the aliment, and impregnating it with that quan- 
tity of saliva which is necessary to enable it to be swallowed. It 
is then, in masses of considerable hardness, forced down the oeso- 
phagus by the action of the spiral muscles of that tube ; and, hav- 
ing arrived at the base, it forces apart the edges of the cleft which 
leads to the first and second stomachs, and enters these viscera 
without being able to reach the maniplus, its volume not permit- 
ting it to pass through the small canal which conducts to that 
viscus. 
When the ruminant drinks any considerable quantity of fluid, 
it penetrates into all the stomachs. We have put this to the test 
of experiment. We have suffered one of these animals to drink 
freely of coloured water, and, on immediately destroying him, we 
have found all four of the stomachs more or less filled with it. 
The Alteration which the Food undergoes in the first and second 
Stomachs. — The food, gradually accumulating in the paunch, dis- 
tends it, and stimulates its parietes. In consequence of this sti- 
mulation, the muscular membrane alternately contracts and relaxes 
itself at several points, following the direction of the fibres, and 
thus producing a slow peristaltic motion. At the same time, it 
secretes, very abundantly, a yellow fluid, somewhat thick, and of 
a slight saline taste, which mixes with the contents of the rumen. 
We have found a fluid of this character both in cattle and in sheep. 
The paunches of the calves which we subjected to examination, 
contained a little straw and some leaves and hay. Those of the 
full grown beasts were filled with hay and chopped straw, or grains 
of epeautre*. The paunch of the sheep usually contained straw, 
grass, and oats. In all of them these substances were most imper- 
fectly, masticated and a little softened. 
* A variety of wheat ( Triticum Spelta ), cultivated in some parts of Ger- 
many as a food for cattle ; and, in Italy, on account of the Leghorn-plat used 
for bonnets. — Y. 
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