64 THE ARTISTIC ANATOMY OF ANIMALS 



backwards. On the posterior surface of this extremity is 

 found a sesamoid bone. 



With regard to the third phalanx, it presents the form 

 of a triangular p^Tamid, and displays a postero-superior 

 concave surface with which the second phalanx articulates ; 

 an anterior, convex surface, which terminates in a point 

 on its anterior part ; and an internal surface, which is 

 flattened. The third phalanx of each digit is contained 

 in a hoof (onglon). 



There is also found in ruminants two imperfect rudimen- 

 tary digits, which are represented by two small bones 

 situated behind the articulation of the metacarpal and the 

 digits which we have just been studying. These rudi- 

 mentary digits are each enveloped in a layer of horn ; they 

 constitute the spurs. The two digits of the ruminants 

 represent the third and fourth fingers of the human hand ; 

 the two lateral digits, greatly atrophied, are the homo- 

 logues of the second and fifth fingers ; the thumb is not 

 present. 



It is the same as regards the metacarpal bones, which form, 

 by their union, the principal metacarpal ; the external repre- 

 sents the fourth metacarpal, and the internal the third. It is 

 to the latter that the tubercle, of which we have already 

 made mention, belongs ; and with the signification of which, 

 because it gives attachment to a muscle, we shall concern 

 ourselves in the section on myology (see Radial Muscles). 



Unguligrades : Horse (Fig. 40). — The scapula is narrow, 

 compared with that of the animals we have just been con- 

 sidering. The anterior border is convex in its superior 

 portion, and concave in its inferior ; the posterior border 

 is slightly hollowed out. The supraspinous fossa is less in 

 extent than the infraspinous ; but the difference is less than 

 that between the same fossae in the ox and the sheep ; in 

 the ox, as we have already indicated, the proportion is one- 

 third ; in the horse, one-half. The spine, which disappears 

 at the extremities, is rough and thick in its middle third, 

 there forming a kind of tuberosity — tuberosity of the spine. 

 Above and in front of the glenoid cavity is found a strong 

 process consisting of a rugous base, and a summit which is 



