33 



The sebaceous glands are branoMng tubes beginning in sacs and 

 opening into the hair follicles. Their oily secretion gives gloss 

 to the hair, prevents it becoming dry and brittle, and keeps the 

 skin soft and supple. 



ANATOMY OF THE FOOT. 



In a broad sense we may regard the foot as consisting of three 

 well-marked portions, — the base or skeleton, the highly sensitive 

 or secreting portions, and a nonsensitive or protective portion. 

 The latter two may be considered as modifications of the skin. 

 The sensitive part corresponds to the derma or true skin, while 

 its covering, the hoof, corresponds to the ejndeimis. 



The study of the foot of the horse is of the greatest practical 

 importance, owing to the many diseases and injuries to which it 

 is liable. It resolves itself into the consideration of the hoof or 

 horny case and the parts contained in it. 



The bones. 



The OS suffraginis, or large pastern bone, passes obliquely 

 downward and forward and articulates with the cannon bone 

 above and the os coronce, or small pastern bone, below. The 

 articular surfaces of the bone are kept in apposition by strong 

 bands of fibrous tissue, known as ligaments. 



The OS coronce, or small pastern bone, is inclined obliquely 

 downward and forward and is partially covered by the hoof. 

 It articulates below with the cofBn and navicular bones, and 

 above with the os suffraginis. The sides of the os coronce are 

 roughened for the attachment of the flexor pedis perforatus 

 tendon. 



The OS navicular is, or shuttle bone, is an irregular bone situ- 

 ated with its long axis transversely behind and below the os 

 coronce and behind the os pedis, with which it articulates, form- 

 ing the so-called navicular joint. 



The OS pedis, or coffin bone, is an irregularly shaped bone 

 situated within the hoof, and which, in a healthy state, cor- 

 responds, somewhat to it in shape, being semilunar in form with 

 the convexity to the front. 



It is a vei'y hard but porous bone, having many excavations 

 and channels for the passage of the arteries and veins. The wall 

 or anterior surface is the semicircular part in front, which 



