EQUIDA 399 
glands, the ducts of which open on the mucous membrane of the 
upper lip. 
The stomach of the Horse is simple in its external form, with 
a largely developed right cul de ser, and is a good deal curved 
on itself, so that the cardiac and pyloric orifices are brought near 
together, The antrum pyloricum is small and not very distinctly 
marked off. The interior is divided by the character of the lining 
membrane into two very distinct portions, right and left. Over 
the litter the dense white smooth epithelial lining of the oesophagus 
is continued, terminating abruptly by a raised crenellated border. 
Over the right part (rather the larger portion) the mucous membrane 
has a grayish-red colour and a velvety appearance, and contains very 
numerous peptic glands, which are wanting in the cardiac portion. 
The cesophayenl orifice is very small, and is guarded by a strong 
crescentic or rather horse-shoe-like hand of muscul:w fibres, which is 
supposed to be the cause of the difficulty of vomiting in the Horse. 
The small intestine is of great length (80 to 90 feet), its mucous 
membrane being covered with numerous fine villi, The cecum is 
of conical form, about 2 feet long and nearly a foot in diameter ; 
its walls are sacculated, especialy near the base, having four longi- 
tudinal fibrous bands ; and its capacity is about twice that of the 
stomach, It lies with its hase near the lower part of the abdomen, 
wnd its apex directed towards the thorax. The colon is about one- 
third the length of the small intestine, and very capacious in the 
greater part of its course. As usual, it may be divided into an 
ascending, transverse, and descending portion; but the middle or 
transverse portion is folded into a great loop, which descends as low 
as the pubis ; so that the colon forms altogether four folds, generally 
parallel to the long axis of the body. The descending colon is much 
narrower than the rest, and not sacculated, and being considerably 
longer than the distance it has to traverse, is thrown into numerous 
folds. 
The liver (Fig. 166) is tolerably symmetrical in its general 
arrangement, being divided nearly equally into segments by a well- 
marked umbilical fissure. Each segment is again divided by lateral 
lissures, which do not extend quite to the posterior border of the 
orgin; of the central lobes thus cut off, the right is rather the larger, 
and has two fissures in its free border subdividing it into lobules. 
The extent of these varies, however, in different individuals, being 
not usually so marked as in the figure, which is from a feetal 
specimen. The two lateral lobes are subtriangular in form. The 
Spigelian lobe is represented by a flat surface between the portal 
fissure and the posterior border, not distinctly marked off from the 
left lateral by a fissure of the ductus venosus, as this vessel is buried 
deep in the hepatic substance, but the caudate lobe is distinct and 
tonguc-shaped, its free apex reaching nearly to the border of the 
