THE LIMBS 



175 



in the anatomy of any animal has been the subject of 

 such minute investigation and elaborate description. It 

 must be confessed that many of the current accounts of it 

 are almost unintelligible, because the broad and interest- 

 ing facts connected with it are completely obscured by 

 a mass of minute, tedious, and unnecessary details, which 

 seem to involve a comparatively simple organ in a cloud 

 of mysterious technicalities. The fact is that in all its 

 main component parts, and in their relations to one 

 another, the last joint of the toe of the horse precisely 

 resembles that of any other animal, although some very 

 remarkable and interesting modifications have taken 

 place, adapting it for the special purpose it has to 

 play in the economy of the horse. 



The last segment or 6 joint ' of the human finger (see 

 fig. 24, p. 178) differs as much from that of the horse in 

 the use to which it is applied as is possible, yet an exami- 

 nation of its structure will afford a good key by which to 

 understand the more complex arrangements of the latter. 

 It contains one bone — the terminal or ungual phalanx. 

 The proximal or upper end of this is wide transversely 

 and hollowed out, fitting by a hinge-joint to the convex 

 surface of the distal end of the second or middle phalanx 

 of the digit. The two bones are firmly bound together 

 by strong ligaments placed on each side of the joint, 

 allowing free movement of flexion and extension, but not 

 in any other direction. Below the joint the bone is 



