JOINTS AND LIGAMENTS. 41 



and each succeeding one is longer than the one next in front of it, till 

 the eighth or ninth rib, the ribs behind which gradually decrease in 

 length up to the last one, which is nearly as short as the first rib. Owing 

 to the direct connection which the first eight ribs have with the breast- 

 bone, their power of movement and, consequently, their action in in- 

 creasing the capacity of the chest is less than that of the false ribs. 

 Hence, when seeking for signs of good breathing power m a horse, we 

 should attach far more importance to rotundity of the rear portion of 

 the chest than of the front part. For practical requirements, the 

 former region might, in the saddled horse, be regarded roughly as 

 the portion of the ribs behind the saddle flaps, and the latter as that 

 covered by them. " It can be proved by observation, that the middle 

 false ribs are those which have the greatest power of being drawn forwards 

 and outwards. The ribs behind them successively lose more and more 

 their power of displacement up to the last one, the lower end of which 

 can be raised and lowered a little, without appreciably altering its distance 

 from the point of the hip " {Colin). 



The jore limb is connected to the trunk by muscles, to which 

 allusion will be made on pages 42 and 43. 



The shoulder joint is a ball and socket articulation which possesses 

 considerable power of motion. 



The elbow is a hinge joint, which can be bent and extended. 



In the knee we have three hinge joints, of which that between the 

 radius and first row of bones is capable of a large amount of 

 motion ; that between the two rows, of much less ; while that between 

 the second row and cannon-bones, possesses hardly any power of 

 movement. 



The bones at the back of the knee are united together by an extremely 

 strong ligament, one of the bands of which closes up the gap left between 

 the point of the pisiform bone and the inside of the knee, so as to 

 form a channel for the " back-tendons " to pass through. 



The sesamoid bones are fixed immovably to the back of the fetlock 

 joint. 



The fetlock, pastern, and pedal {coffin) joints are hinge joints, which 

 possess more or less play. 



The hip joint, formed by the head of the thigh bone and cavity in the 

 pelvis, is a ball and socket joint. 



In the stifle we find two articulations — one with the thigh bone and 

 tibia, the other with the thigh bone and patella, which is firmly attached 

 to the tibia by ligaments, in order to enable it to resist the action of those 

 muscles of the thigh which are inserted on it. 



The true hock joint is formed by the tibia and astragalus. It is a 

 hinge joint, which, owing to the oblique manner its grooves are 

 placed, causes the foot to be turned slightly outward when the joint 



