PHYSIOLOGICAL PARADOXES.' 



sufficient attention to the correspondences to 

 be surprised when they fail, note with interest 

 that in the horse the hind knee bends back- 

 wards, whereas in man it bends forwards. 



The fact is that the joint at E is not a knee 

 at all. 



Between the diagrams of the human leg 

 and the horse's hind-leg have been inserted in 

 Fig. 64 three other diagrams showing inter- 

 mediate conditions, the five being arranged 

 in series. If these five be examined it will 

 be clearly seen that in the number and succes- 

 sion of bones and joints each diagram corre- 

 sponds strictly with those adjacent to it, having 

 only a slight modification in the length and 

 direction of any part. The first diagram, there- 

 fore, corresponds truly with the last, and it is 

 impossible to deny that the joint E in a horse's 

 hind leg answers to the joint F in the human 

 leg. 



What we commonly call a horse's knee is 

 therefore an ankle. And its back part G cor- 

 responds to the heel H. Beneath this heel- 

 bone, in the horse, the same joint contains some 

 smaller bones which represent the small bones of 

 the tarsus in man, just in front of the ankle-joint. 

 Then comes a fairly long bone, K, the common 

 bone, or, as most people call it, the shin-bone. 

 It is, however, no shin-bone at all. 



To what does it correspond in the human 

 skeleton ? Evidently to L, the first long bone 



300 



