POSTERIOR EXTREMITY 15 



before to the croup and haunch, with which they unite behind. The 

 bones which enter into its formation are usually six in number, and 

 they differ in their skeletal relations from those of the back and withers 

 in having no ribs connected with them. On either side of the loins 

 below this reo-ion is the Hank. 



The Croup. — The croup is the uppermost part of the quarters situated 

 between the loins and the tail. Below on either side it joins the thighs 

 and upper part of the buttocks. The haunch-bones concur with the 

 sacrum in forming the basement structure of this region, on which are 

 situated a number of large important muscles of locomotion. Of these, 

 some are eng;ao;ed in the movements of the hind limbs, while others 

 act upon the spine. The form, length, and width of the croup varies in 

 different animals. In the mare, during the later stages of pregnancy, the 

 muscles of this part become depressed, or sink downward, especially 

 towards the root of the tail. This is generally described as a " siidcing 

 of the haunch-bones " or " falling of the hips ". It results, however, from 

 a relaxation and yielding of the broad ligaments of the pelvis, on which 

 some of the muscles rest. 



Jlie Point of the Haunch is a division of the quarter commonly 

 spoken of as the "point of the hip". It is situated in front of the 

 croup, behind and below the loins, and in proximity with the flank. 



It is formed by the projecting outer angle of the iliuni or haunch- 

 bone. Owing to its prominence, this part is specially liable to injury 

 from forcible contact with doorways, and in slipping- up it not in- 

 frequently suffers by contact with the ground. Fracture and displace- 

 ment of the bone are of frequent occurrence, and give rise to that state 

 known as " down at the hip". 



3. POSTERIOR EXTREMITY 



The Tail. — The tail consists of from twelve to fifteen vertebrse, en- 

 closed in long tapering muscles, and these are invested with a layer of 

 skin covered with long hairs. It emerges from, and is continuous with, 

 the spinal column. On either side its base is in relation with the croup, 

 and below with the anus, which it covers. 



The Anus. — The anus is the terminal extremity of the intestinal 

 canal, through which the excrement leaves the body. As we have just 

 remarked, it is situated beneath the tail, and below it is a smooth hair- 

 less length of skin termed the Perineum. The anus is surrounded by 

 a circular muscle termed the Sphincter Ani, which, by its power of 

 contracting, prevents the involuntary escape of the f^ces. In old animals, 



