9 



foot, or frog and this is designed to break the hard impact of the Hmb when com- 

 ing in contact with the ground. Fig. 17. 



This adaptation is best illustrated in the foot of the zebra, in which we have 

 a perfectly developed frog which is springy and cushion-like. As a matter of 

 fact, the zebra does land distinctly upon that elastic body ; not only so, but it 

 also lands occasionally on the back of the fetlock. Fig. 18. 



In the interior of the foot we have removed part of the crown of the hoof 

 or nail, in such a manner as to show the terminal joint of the finger, corres- 

 ponding with the last bone or third joint of the finger. This bone comes down 

 and rests flatly upon a beautiful elastic cushion which extends beneath its 

 lower surface in such a way as to take off the shock which would naturally be 

 transmitted through the crown, through the sole and through this cushion, so 

 that even without the aid of the frog the shock or impact with the crown is 

 lessened as much as possible. Fig. 17. 



I may now mention a comparatively recent discovery of Prof. Ewart's, 

 namely, the true interpretation of the so-called ergots in the fetlocks of the 

 horse, which are found just at the back of the fetlock joint, also of the chest- 

 nuts which are found on the inner side of the limb considerably above the knee 

 of the horse. Ewart has recently been demonstrating that beginning with the 

 frog, the ergots and the chestnuts, we have three calloused pads of skin which 

 correspond, looking at the foot of the dog, with the pad which lies at the tip of 

 the foot, with the pad which supports the middle portion of the paw, and with 

 the pad which goes to support the wrist. 



These structures to which so little attention has been directed, have been 

 found of late to be very significant as regards the various breeds of horses. The 

 ergots are large in the zebra, which rests on the fetlock joint in rapid speed or 

 on hill sides, when the foot comes to the ground. The ergot is seen in the 

 donkey's foot. In the Arab horse it is greatly reduced, now a vestigial or- 

 gan, the chestnuts are also small. From these facts we have one of the best 

 means of determining the presence or absence of Arab blood m a horse, be- 

 cause it has been noted that small ergots and chestnuts are a universal charac- 

 teristic of the Arab breed. On the contrary they are very large in the cart 

 horse, which is the very opposite of the Arab, and very small in the thorough- 

 bred, which is derived from the Arab. One of the first points therefore in order 

 to determine the blood of a horse, is to glance at these vestigial structures. A 

 sign of what we call 'low breeding' is almost invariably found in the presence 

 of very large ergots and chestnuts, and conversely, a sign of high breeding is 

 found in the small or reduced development of those two pads. Fig. 18. 



An epitome of the development of the foot is from the four-toed type 

 to the three-toed type; to the type in which the lateral toes are raised entirely 

 off the ground ; to a type in which they are still further raised above the ground ; 

 to the type of the modern horse, where the fingers persist in their reduced con- 

 dition of splints. In the modern horse, the splints, commonly uniting with the 

 main cannon bone, become one of the greatest danger points, as the 

 seat of a disease often developed by exercising the horse on very 

 hard ground at a time before those bones have united. This is an interesting 



