736 



SOLIPEDA. 



terminate where the rectum begins, the last- 

 named division of the alimentary canal pre- 

 senting only a few pouches of comparatively 



small size, in which the faeces become moulded 

 into balls preparatory to their expulsion. 

 When in a state of moderate distension, the 



Fie. 512. 



Colon of the Mare in Situ. 



small intestines of an ordinary size are found 

 to measure about fifty-six feet in length from 

 the pylorus to the caecum, with a circumference 

 varying according to the state of contraction 

 of the bowel from two inches and a half to 

 six inches. The csecum is about two feet and 

 a half long, and about two feet in circumfer- 

 ence at its broadest part; but towards its 

 blind termination it assumes a conical form, and 

 terminates in a point (fig. 511.6). Above 

 the ileo-caecal junction, the intestine forms a 

 cul-de-sac (fig. 51 !.<?), which is bent upon 

 itself so as almost to resemble a second caecum 

 separated from the rest of the colon by a deep 

 contraction, and there is, moreover, sometimes 

 a third globular cavity, situated as shewn in 

 fig. 51 1./: but this is r.ot constantly present. 

 The enormous colon (fg. 512. a, b, c, ef), 

 which seems of itself to occupy the whole 

 abdominal cavity, is divided into two por- 

 tions : the first (a, b) is about 2 feet 

 3 inches long, and, at least, two feet in 

 circumference ; the second portion (c, d) is 



of nearl v the same dimensions ; but towards 

 its termination, its circumference diminishes 

 to 10 inches, and the continuation of the 

 bowel retains that size for the length of a 

 couple of feet, when it again enlarges to a cir- 

 cumference of 2 feet 4 inches before its ter- 

 mination in the rectum. 



The entire length of the colon and rectum 

 taken together is 21 feet, which, added to the 

 length of the small intestines, gives a total 

 length of 77 feet for the intestinal canal, ex- 

 clusive of the caecum. 



Liver. This viscus in the horse is divided 

 pretty equally between the left and the right 

 sides of the body. It is divided into four 

 lobes, measures about a foot and a half in its 

 greatest diameter, and weighs between four 

 and five pounds. There is no gall-bladder ; 

 but the hepatic duct is extremely capacious, 

 and evidently forms a receptacle for the biliary 

 secretion. 



Spleen. The spleen of the horse has the 

 shape of an elongated triangle, situated, ob- 



