OF THE CLASS MAMMALIA. 



253 



nation), and thence transmitted into the following compart- 

 ments, without again passing into the first. 



These stomachs, or stomachal compartments, in ruminants 

 are four in number. The first, which is the largest, is called 

 the paunch (Fig. 216) ; its surface is furnished with papillae 

 and an epidermic covering (Fig. 217) ; it fills a large part of 

 the left side of the abdominal cavity. The second stomach, 

 called the king's hood, is small, and looks like an appendage 

 of the paunch. But it differs internally (Fig. 217), being 

 composed of a number of folds disposed so as to form polygonal 

 cells or cellules, like honeycomb. The third stomach, not so 

 small as the second, is called maniplus, from the number of 

 longitudinal folds seen in its interior : finally, the fourth is 

 called the rennet : its property of curdling milk renders it 

 remarkable. The first, second, and third stomachs commu- 

 nicate directly with the gullet, which indeed seems to open 

 equally into the first and second. After being ruminated, 

 the food descends from the gullet into the third stomach by 

 means of a semi-canal, which no doubt becomes complete at 

 the time, thus directing the food in one course only, diverting 

 it from the paunch and second stomach; from the maniplus, 

 it passes into the rennet or fourth stomach, in which cavity 

 digestion is finally completed. 



The act by which the food passes when first swallowed 

 into the paunch and thence to the second stomach, but which 

 on being ruminated or remasticated descends only to the 

 third by means of the cesophageal canal, is not an act of intel- 

 ligence, but one purely instinctive, and perhaps even mecha- 

 nical, due to the anatomical disposition of the structures. 

 Food of the size it is when first swallowed, opens mechanically 

 the semi-canal, by which the gullet communicates with the first 

 and second stomachs; but fluids and the remasticated food being 

 much finer, do not effect this, and thus pass on by the canal 

 into the maniplus or third stomach. Rumination is generally 

 ascribed to the second stomach, but it appears more probably 

 due to a combined action of the first and second, which, by 

 contracting, forces the bolus again into the gullet, by whicn 

 it remounts to the mouth. 



The paunch is of very great size in the adult animal; 

 in the young, whilst living on the milk of the mother, 

 it is smaller than the rennet, thus showing (?) the in- 

 fluence the food exercises in enlarging the capacity of the 

 organ. 



