Book VII. 



PHYSIOLOGY OF THE HORSE. 



969 



in water, and then forms leather ; and the value of the horse's Iiide in this particular is sufficiently 

 known. 



6362. Adipose membrane and fat. These form very considerable parts of the body of most animals. 

 The adipose membrane is not so universal as the skin ; some parts are completely without it, as the eye- 

 lids, ears, sheath, and some portions of the extremities. It is cellular, but the cells fortunately do not com- 

 municate or the fat would gravitate. The fat is the unctuous juice poured or rather secreted into these 

 cells. It appears in greater quantities in some parts than in others, and in different degrees of consist- 

 ence ; in the belly of some it is lard, and suet in others ; within the bones it is oleaginous in all. Different 

 quadrupeds have their fat of different degrees of consistence, from the firm suet of the ox, and the tallow 

 of the sheep, to the soft lard of the hog, and the intermediate state of the horse; it guards the parts.it 

 preserves warmth ; but above all, it is a depot against occasional want : thus a fat animal can sustain itself 

 without food much longer than a lean one. The torpid bear comes from his hibernation emaciated, be- 

 cause his constitution has been subsisting on his fat. 



6363. Cellular tnembrane. (1849.) This complete investure of the body enters every part, and is formed 

 of communicating cells ; as we see by the practice of butchers who blow up their meat; and also by the 

 emphysematous effects of a fractured rib, and the gaseous distention in some putrid diseases. It exists in 

 different quantities, and under various modifications of density throughout the body, and is a very uni- 

 versal medium of connection in the form of ligament. 



63f)4. Pannlculus carnhsus. (18+8.) The fleshy pannicle was kindly given to quadrupeds in lieu of hands, 

 to enable them to corrugate or pucker the skin, and thus to shake off dust and insects. It is a thin mus- 

 cular expansion peculiar to brutes, but not to all ; the swine family being denied it. By its attachments 

 it can operate variously, as we see by the uses the horse makes of it. It is very vascular and sensible, also, 

 from the numerous nerves which enter it. 



SuBSECT. 6. The Head genei'ally. 



6:365. The parts qf the head are external and internal ; some of these have been touched on, as the in. 

 teguments, &c. : such as have not will follow in the order of their magnitude or situation. 

 6366. The brain of the horse {fig. 831. a, b, c), contained within the hollow of the skull, is so similar to 



831 



that of man, that to describe the one is to portray the other. Like the human, it is composed of ct re- 

 brum {a\ cerebellum (6), and medulla oblongata (c). The mediilla spinJilis is a direct continuation 

 of the brain in the form of a medullary cord, called the pith or spinal marrow {k), which jwsses out ot 

 the skull through the occipital foramen. The brain appears to be the organ of consciousness, and the 

 nerves which arise out of the medullary cord are the messengers by which sensation and volition are dis- 

 tributed to the various parts of the body. 



SuBSECT. 7. The Ear. 

 6367. The ears of the horse are composed of inner and outer parts. The internal parts do not differ 

 from those of the human, but the outer are adapted to his situation and habits. These exterior parts aie 

 composed of the skin, the outer hair, the cartilages, and the muscles by which thoy are moved. J he skm 

 within the ears is furnished with sebaceous glands, which secrete a bitter matter, noxious to insects : and 

 further to guard against these, it is filled with hair ; which the false taste of grooms induces them to re- 

 move, and thus to expose the animal to dust, hail, rain, and insects. 



