252 OUTLINES OF EQUINE ANATOMI. 



rienced during sexual intercourse. It is surrounded "by 

 a mucous fold, prseputiiim clitoridis, whicli covers its free 

 extremity, and centrally presents a depression leading into 

 a blind sac, wliicli generally contains an odorous oily 

 matter. This organ is fixed by two crura to the ischial 

 arch, has two erectores clitoridis running to its substance 

 from the same part, a,nd presents a corpus cavernosum, a 

 corpus spongiosum, and a cjlans. 



The young animal at birth being incapable of supplying 

 itself with nutriment, and even incapable of digesting or- 

 dinary alimentary matters, is for a time supplied with 

 milk produced by the mammary gland of the dam. This 

 function the mare shares in common xvWh all the females 

 of the higher order of vertebrated animals, mammalia. 

 Situated between the thighs are two prominences, from the 

 under part of which small finger-like portions project, 

 having at their extremity three or four small openings. 

 These are the teats, and they are covered by a continuation 

 of the delicate skin investing the mammary glands. They 

 are longest in the animal which has " given suck." The 

 faschia superficialis abdominis, at the postero-inferior part 

 of the abdomen of the mare, is reflected downwards to 

 invest the mammary gland. It sends in septa between 

 the different lobes, for this is a racemose gland, presenting 

 a structure similar to that of the salivary glands. Its 

 primary secreting saccules, lined by spheroidal epithelium, 

 open mto the primary ducts, which unite and reunite with 

 those from other j^arts of the gland, until at length they 

 terminate in a dilated cavity at the base of the teat, galac- 

 tophorous sinus. This is divided into parts corresponding 

 in number, and leading by ducts to the openings on the 

 teats. The teats contain yellow elastic tissue, but no mus- 

 cular fibre, for the milk is withdrawn by the suction action of 

 the young animal. Around the openings the skin becomes 

 continuous with the mucous membrane of the glands. 



Milk consists of water with an albumenoid matter, 

 casein (cheese), and salts, in solution. Floating in it are 

 numerous fat- globules, which form the cream. The first milk 

 produced after foaling contains a number of the epithelial 

 cells of the gland in a state of fatty change, a number 

 of fat-globules being connected together by the tough 

 w^all of the cell, forming the peculiar colostrum-corpuscles, 

 for this milk is termed colostrum (or beastlings). It has a 



