328 



COMPARATIVE PHYSIOLOGY. 



fibers constituting sphincters by which their openings inward 

 may be closed. These cells number several hundred, and are 

 capable of containing some quarts of water. 



Fig. 271.— a. Stomach of sheep. B. Stomach of mii6k-deer. ce, oesophagus; Bn, ru- 

 men; Ret. reticulum; P5, psaltesium; A. Ab, abomasum; Du, duodenum; Py, 

 pylorus (Huxley). 



• The manyplies is so named from the arrangemient of its 

 mucus membrane in folds, a condition, however, not equally 

 well marked in all ruminants. 



A structure known as the oesophageal canal, (furrow, groove) . 

 communicates with the first three stomachs. During swallow- 

 ing, its lower portion is raised above the level of the third 

 stomach, so that it is likely that this is a barrier against the 

 entrance of all except liquids or soft foods into the manyplies. 



It is diflflcult to make any positive statement as to what other 

 part it may take in determining the direction of food when en- 

 tering or leaving the various stomachs. It does not seem to be 

 essential to return of the cud. 



