THE 
ANATOMY OF THE HORSE. 
CHAPTER XVII. 
CLASSIFICATION OF THE VARIOUS ORGANS, AND PHYSIOLOGY OF THR 
SKELETON, 
CLASSIFICATION OF THE VARIOUS ORGANS—STRUCTURE OF BONE—OF THE SKELETON 
IN GENERAL—THE ARTIFICIAL SKELETON—-NUMBER OF BONES COMPOSING THE 
SKELETON—GENERAL ANATOMY OF THE SPINAL COLUMN—OF THE HEAD AND FACE 
—OF THE HYOID ARCH—OF THE THORACIC ARCH AND ANTERIOR EXTREMITIES— 
OF THE PELVIC ARCH AND HIND EXTREMITIES—OF THE TAIL—OF THE FORE AND 
HIND EXTREMITIES CONSIDERED AS ORGANS OF LOCOMOTION, 
CLASSIFICATION OF THE VARIOUS ORGANS. 
THE Bopy oF THE Horst, like all the vertebrate animals, may be con- 
sidered as made up of several distinct apparatuses or systems. Of these, 
the jirst is a machine composed of the bony skKELETON, or framework, the 
various parts of which are united by somnts and moved by MuscLEs. 
Secondly, there are contained within the thorax the organs which supply 
the whole body with the means of nutrition in the form of blood, and 
purify this fluid. Thirdly, in the abdomen are presented to view the 
important organs which assimilate the food to the condition of the blood; 
while in the adjoining cavity, the pelvis, are the urinary and generative 
apparatuses. ourthly, the nervous system may be considered, as com- 
prising the grand centre of the mental faculties, and, also, as presiding 
over and controlling the whole of the functions performed by the several 
organs ; and jifthly, certain special organs, as, for example, those of sense, 
and, likewise, the foot will complete the whole circle of systems to be 
reviewed. Hach of these groups will, therefore, be described in a separate 
chapter. 
OF THE STRUCTURE OF BONE. 
THE BONES are composed of a tissue peculiar to them, enveloped by a 
membrane, the pertostewum. They contain a semi-fluid of a fatty nature, 
the marrow, and are pierced in various directions by blood-vessels and 
nerves, 
THE PROPER TIssuE of the bones is made up of two distinct substances, 
either of which may be removed by artificial means, leaving the other 
entire. If, for instance, a bone is submitted to the heat of a furnace, it 
Me 
