100 THE ARTISTIC ANATOMY OF ANIMALS 



from that of the bone of the opposite side is proportionately 

 less. 



The internal iliac spine, which is conical in shape, and 

 curved upwards, forms a prominence known as the angle of 

 the crupper ; the external iliac spine, thick and provided 

 with tuberosities, forms a clearly-defined prominence ; this is 

 the angle of the haunch. 



The iliac crest, extending directly from one spine to the 

 other, is curved, its concavity being turned upwards. The 

 external iliac fossa, which looks upward, is limited anteriorly 

 by this crest, and is, like the latter, slightly hollowed. The 

 portion of the bone which connects the ilium to the region 

 occupied by the cotyloid cavity is extremely narrow ; pos- 

 teriorly, the bone enlarges again to form the ischial and 

 pubic portions. 



The tuberosity of the ischium, thick and curved upwards, 

 but less so than in the ox, forms the most prominent part of 

 the posterior border of the region of the thigh ; this project- 

 ing portion, so sharply defined in spare subjects, is known 

 as the point or angle of the buttock. Contrary to what we have 

 indicated in the case of the dog, the distance which separates 

 the ischiatic tuberosities is inconsiderable in proportion to 

 that which we find between the external iliac spine of one 

 side and that of the opposite. The bi-ischiatic diameter 

 does not even equal the width of one iliac bone measured 

 at the level of its crest (Fig. 53). On the skeleton of the 

 horse in the Ecole des Beaux- Arts, the distance which sepa- 

 rates the tuberosities of the ischia is 225 millimetres ; that 

 between the two spines of each iliac bone is 25 centimetres. 



The anterior region of the crupper is thus much broader 

 than that occupied by the ischia. 



The femur is relatively short. Its shaft is rectilinear, and 

 does not present the anterior convexity which is found on 

 the human femur, and which we indicated when discussing 

 that of the dog. The shaft of the bone, instead of being 

 prismatic and triangular, presents four surfaces ; the 

 anterior, internal, and external, almost pass into each other, 

 being separated one from the other merely by rounded 

 and slightly marked borders ; the posterior surface, which 



