SOLIPEDA. 



735 



pharyngeus*, its fibres descending from the 

 pterygoid and palate bones, along the sides of 

 the pharynx, around which they wind obliquely, 

 uniting in the middle line upon its posterior 

 surface, where they form a thick muscular 

 layer. 



The inferior constrictor, or thyro-pharyngcus, 

 is equally broad and strong, its fleshy fibres 

 taking nearly the same direction as they pro- 

 ceed towards the back of the pharynx, where 

 they join by a median raphe. 



In addition to the above, there is a crico- 

 pharyngeus, arising from the posterior and 

 inferior margin of the cricoid cartilage, whence 

 its fibres extend obliquely upwards along the 

 sides of the pharynx. 



The analogue of the stylo-pharyngeus is, 

 in the Solipeds, a cylindrical muscle derived 

 from the styloid bone, and, running from be- 

 hind forwards upon the sides and upper part 

 of the pharynx, mixes its fibres with those of 

 the superior constrictor its action is to raise 

 the commencement of the pharyngeal sac, 

 which it at the same time dilates and draws 

 backward. 



There is likewise a small muscle derived 

 from the middle part of the styloid bone, the 

 fibres of which run backwards anil inwards, so 

 as to meet those of the muscle last men- 

 tioned. 



Lastly, there are two other muscles, the 

 fibres of which take a longitudinal direction. 

 One of these, the pkaryngeus proprlns, arises 

 from the tendinous middle line that extends 

 from below the insertion of the stylo-pha- 

 ryngei, and is prolonged downwards along the 

 posterior and lateral walls of the oesophagus : 

 the other, the aryteno-pharyngcus, is a small 

 muscular band proceeding from the back part 

 of each arytenoid cartilage, and running down 

 the front of the oesophagus towards the sto- 

 mach. 



Stomach. In all the Solipeda the stomach 

 is simple, and presents little remarkable in its 

 shape. The oesophagus (Jig. 510. b) is in- 

 serted at a very acute angle into its smaller cur- 

 vature, which is, as it were, folded upon itself. 

 The cardiac cul-cle-sac (c) is very capacious, 



Fig. 510. 



and is lined throughout internally with a thick 

 cuticular layer continuous with the lining of 

 the oesophagus, and extends nearly as far as 

 the middle of the stomachal cavity, where it 

 terminates abruptly by a prominent indented 

 edge, the interior of the pyloric half of the 

 viscus (,</) presenting the usual villous mu- 

 cous surface. The muscular coat of the 

 stomach consists of several superimposed 

 layers of fibres that cross each other in differ- 

 ent directions, some of them being apparently 

 derivations from the muscular bands of the 

 oesophagus ; and it is doubtless the contrac- 

 tions of these muscular bands, in conjunction 

 with the obliquity of the entrance of the oeso- 

 phagus, that renders the act of vomiting im- 

 possible in these animals. 



The alimentary canal in the Solipeds is 

 short in comparison with that of the Rumi- 

 nants and some other herbivorous quadru- 

 peds ; but this want of length is perhaps 

 more than made up for by the enormous 

 capacity of the large intestine, which, on first 

 opening the body of one of these animals, 

 seems of itself to occupy the whole of the 

 abdominal cavity. 



Commencing from the pylorus, the duo- 

 denum (Jig. 510. f.) is found to be considerably 



Fii>. 511. 



Stomach of the Horse. 



* Cuvier, Lemons d' Anatomic Comparee, torn. iv. 

 p. COG. 



Caput Coll Sfc. of the Horse. 



dilated ; but its diameter soon contracts, and 

 the rest of the tract of the small intestines is 

 of pretty equable dimensions throughout, or 

 if it presents constrictions here and there, 

 they disappear when the gut is distended with 

 air. The iliac portion of the small intestine 

 (fig. 51 1. d) terminates in a caecum of enor- 

 mous bulk (Jig. 511. a, b, c,c,f), which is 

 separated from the commencement of the 

 colon by a deep constriction (g) : the colon 

 itself is throughout its entire extent propor- 

 tionately voluminous, commencing in the right 

 flank: its ample folds (Jig. 512. a, 6) mount 

 upwards as far as the diaphragm, whence they 

 descend again, forming a viscus of vast capa- 

 city as far as the left iliac region, where, be- 

 coming gradually contracted in its dimensions, 

 it terminates in the rectum. The ascending 

 portion of the colon (a, b} is separated from 

 the descending part (c, d) by a constriction ; 

 and the latter forms a third remarkable dila- 

 tation before it ends in the rectum. The 

 whole colon is puckered up into huge sacculi 

 by three longitudinal muscular bands, which 



