EUMINANTIA— DIGESTIVE SrSTEM. 371 



muscular resembles that of the horse, while the mucous is covered by a thin 

 layer of epithelium, and studded with glands and follicles, which secrete 

 gastric juice. 



The stomach thus described may be termed the typical ruminant stomach, 

 as it exists in the cavicornia, and in most deer (constituting the group 

 Cotylophora of Professor Huxley). In the camel there are certain compart- 

 ments or diverticula in the rumen, which serve to store up a quantity of water. 

 The psalterium is devoid of leaves, and is not well developed. In one group 

 of deer, Tragulus, the psalterium may be said to be absent, being represented 

 only by a short tube joining the reticulum and abomasum ; in this group the 

 oesophagus marks the line of separation between the rumen and the reticulum. 



By most of the best authorities the process of rumination is believed 

 to be effected somewhat as follows : — The food having been masticated and 

 swallowed, falls icto the first compartment, where it is tossed about by 



Fig. 132. 

 Stomach of a Miisk Deer, left aspect— the last three 

 compartments opened and reflected forwards. Rn, 

 Kumen ; Rt, Eeticulum ; Ah, Abomasum ; Py, Pylorus ; 

 OS, CEsophagus ; X, Opening of the tube which represents 

 the psalterium ; Spl, Spleen. 



muscular action and saturated with fluid ; a portion is thrown up through the 

 valvular\ opening into the reticulum, and gains a further supply of mucous 

 fluid, and the finer are separated from the coarser pai-ticles ; the former pro- 

 ceed to the psalterium ; the latter, by the muscular contraction of the reticu- 

 lum, the relaxation of the cesopbageal pillars, and anti-peristaltic action of the 

 oesophageal walls, is returned to the mouth to be remasticated, and once more 

 swallowed ; a portion now passes into the rumen, the remainder down the 

 oesophageal canal to the psalterium, whence liquids flow onwards to the 

 abomasum, while solids are drawn between the leaves of the psalterium to be 

 further prepared. 



The Intestines. 



The small intestine of the ox differs little from that of the horse, except that 

 it is smaller in calibre, but on an average double the length. Beyer's patches 

 are larger, but not so numerous. 



