136 INTRODUCTION. 



Among the Quadrumana, one group of the Monkey tribes (the 

 genus Semnopithecus) is remarkable for the sacculated condition of the 

 stomach, no less than for its amplitude. 



It is, however, in the Rurm'nantia, that the most complicated structure 

 of the stomach prevails a structure connected with the process of rumi- 

 nation, or the return to the mouth, and remastication, of the herbage, 

 coarsely ground and swallowed, but which is to be remasticated to a 

 fine pulp, and then transferred to a different compartment from that 

 into which it was previously conducted. The stomach of the Ruminantia 

 consists (as seen in figs. 135, 136) of four distinct cavities : the oesopha- 

 gus, a, enters the first of these, viz., the rumen, or paunch, b, b, divided 

 by a muscular band into two pouches : to this succeeds the reticulum, 

 or honeycomb, c ; then the maniplus, or manyfolds, d ; and, lastly, the 

 abomasum, or rud, e, the true pyloric cavity, in which digestion really 

 takes place. 



135 136 



Stomach of Ox, two views. 



Fig. 135, external; 13 r l, laid open, so as to expose the internal structure. a, the ossophagus; b, b t the rumen; c, the 

 reticulum; d, the mauiplus; e, the abomasum; /, the intestine. 



It may be observed, that, between the most simple form of stomach, 

 and the most complicated, there are many intermediate grades ; and 

 that, among the most simple, and, also, the most complicated, im- 

 portant modifications occur, both as to form, the character of the lining 

 membrane, amplitude, and various other particulars. Hence it is, that 

 Cuvier divided the complicated class of stomachs into such as are simply 

 so, being composed of sacculi, or compartments, all having the same lining 

 membrane, and into compound stomachs (composes), which, in addition 

 to being complicated, are lined with membranes diversly organized. In 

 the same way may simple stomachs be divided : some, instead of being 

 universally lined with a mucous tissue, have the cardiac portion lined with 



