THE STIFLE. 883 



The thigli-bone is both the largest and strongest in the frame. It in 

 short and thick, and cxliibits singular prominences and roughnesses and 

 hollows for the insertion of the immense musqles that belong to it. Four 

 prominences, in particular, called by anatomists troclianters, two on the 

 outside, one on the inside, and one near the head of the bovue. 



This bone is commonlj called the Round Bone. It has, in some rare in- 

 stances, been dislocated and fractui*ed. It is much oftener sprained, but 

 not so frequently as the groom or farrier imagines. There is nothing pe- 

 culiar in the lameness to detect injuiy of this part, except that the horse 

 will di-ag his leg after him. Injury of the round bone will be principally 

 discovered by heat and tenderness in the situation of the joint. 



A part so deeply situated is treated with difficulty. Fomentations 

 should first be used to abate the inflammation, and, after that, an active 

 blister should be applied. Strains of this joint are not always immediately 

 reHeved, and the muscles of the limb in some cases waste considerably : 

 it therefore may be necessary to repeat the blister, while absolute rest 

 should accompany every stage of the treatment. It may even be requisite 

 to fire the part, — or, as a last resort, a charge may be placed over the joint, 

 and the horse turned out for two or three months. 



THE STIFLE. 



The inferior extremity of the femur presents a pulley-Hke articulatory 

 surface in front, over which plays the patella, and two condyles, rounded 

 and smooth, presenting inferiorly and posteriorly, and Avhich are received 

 into slight depressions on the upper surface of the lower bone, the tibia ; 

 while in front is a curious groove, over which plays a small irregular bone, 

 the patella, or stifle-bone. The whole is commonly called the stifle-joint. 

 The patella (Q, p. 140) answers to the kneepan in the human subject. Some 

 of the tendons of the strongest muscles of the upper bone of the thigh are 

 inserted into it. This important joint is much strengthened by the proper 

 ligaments between the upper and lower bones, and additional ligaments 

 from the patella, forming altogether a very powerful imion. The patella 

 likewise answers another and even more important purpose. The tendons 

 of some strong muscles are inserted into it. When these muscles are not 

 in action, the patella lies in the groove which nature has contrived for it ; 

 but when they begin to contract, it starts from its partial hiding-place, 

 becomes prominent from the joint, and alters the hue of direction in which 

 the muscles act. It increases the angle, and thus very materially increases 

 the power of the muscles. 



The lower bone of the thigh consists of two parts. The larger portion, 

 in front, extending from the stifle to the hock, is called the tibia. The 

 smaller bone, or flhala, behind (see R, p. 140), reaches not more than a 

 third of the way down. It is united to the shank-bone, like the splint- 

 bone, by a cartilaginous substance, wliich is soon changed into a bony one. 

 Of the use of the smaller bone we cannot s^ieak. 



The lower bone of the thigh forms an angle with the upper one, being 

 the reverse of that which exists between the upper bone and the pelvis. 

 The object of this is twofold, — to obviate concussion, and to give a 

 direction to the nmscles favourable to their powerful action ; and in pro- 

 portion to the acuteness of the angle, or the degree in which the stifle is 

 brought under the horse, mil these purposes be accomplished. There is 

 much difference in this in different horses, and the construction of this 

 part of the frame is a matter worthy of more regard than is generally paid 

 to it. 



This part of the thigh should likewise be long. In proportion to the 



