THE KNEE. 217 



inches in length. MM. Goubaux and Barrier state, as an 

 extremely rare occurrence, that absence of castors from the 

 fore legs has been observed in horses. There are, in almost 

 all cases, similar, though somewhat smaller, castors on the 

 inside of the hind limbs, just below the hock and near the 

 back of the lee. M. Huzard and MM. Goubaux and Barrier 

 remark that they have seen instances of the hind castors 

 being absent in the horse. They are larger and of a more 

 horny texture in coarse-bred horses than in blood animals. 

 Nothing is known of the origin of castors {see p. 303). 



Knee. — Looking at the knee in profile, while the horse 

 bears weight on the leg, vv^e should find that the cannon-bone 

 and radius are nearly in a straight line. In reality they are 

 not quite so in perfect specimens ; but are united by a slightly 

 undulating line of great beauty, the contour of which I am 

 unable to lay down with mathematical accuracy. Pis. 

 39, 41 and 55 furnish us with admirable illustrations of well- 

 set-on knees. Pis. 35 and 40 are also good. Pis. 34 and 

 45 are examples of the condition known as "calf-knees," to 

 which there is a slight tendency in Pis. 36 and 47. The 

 opposite formation ("being over at the knees") is shown in 

 PL 46, to w^hich there is an inclination in PI. 59. This 

 condition is generally due to hard work. 



The fact of a horse being ''calf-kneed'" renders the back 

 tendons and check ligaments (not the suspensory ligaments, 

 the attachments of which are below the knee) more liable 

 to sprain by violent descent of the fetlock than if the knee 

 were straight. It tends, however, to make the animal more 

 sure-footed, by bringing the weight back from the toe. 

 In all cases this condition adds to the tension to which the 



