OSTEOLOGY AND ARTHROLOGY 107 



But it should be understood that one part of this de- 

 scription—that which has relation to the leg — holds good 

 only when the femur is in its normal condition, or in flexion. 

 Indeed, at the close of the movement in which, during a step, 

 the foot is in contact with the ground — that is, at the termina- 

 tion of the resting stage — the inferior extremity of the tibia 

 is directed backwards. But the femur is then in a state of 

 extension, and in regard to this latter the attitude of the 

 leg is unchanged. 



At this moment, notwithstanding the direction, which 



Fig. 55. — Extension of the Leg : Right Posterior Limb of the 

 Horse, External Surface. (After a Chronographic Study by 

 Professor Marey.) 



recalls that which it has at the time of flexion, the leg is not 

 bent on the thigh ; on the contrary, it is almost in the line 

 of its continuation (Fig. 55). As we have done in connec- 

 tion with the articulations of the anterior limbs, we borrow 

 this figure from the interesting chronophotographic studies 

 of Professor Marey.* 



The Tibio-tarsal Articulations and of the Bones of the 

 Tarsus. — In the region which veterinary anatomists call the 

 ham, the articulations of the leg and foot alone call for special 



* E. J. Marey, ' Analysis of the Movements of the Horse by the Chrono- 

 photograph ' {La Natitra, June ii, 1898). 



