LOCOMOTOR SYSTEM 617 



the under and never the upper surface of the navicular which is 

 affected with caries, though these surfaces are not \ inch away 

 from each other. It is the inside and not the outside of the hock- 

 joint which is affected in spavin. The seats of these affections are 

 not matters of accident, but due to definite causes which the writer 

 considers are intimately concerned with the physiology of the parts. 

 In concluding this brief outline of the physiological aspect of lame- 

 ness, attention must be drawn to the fact that it is the small and not 

 the large joints which usually suffer ; it is not those at some distance 

 above, but those nearest to the ground. It is not the fibrous tissues 

 so frequently as the denser structures. Speaking generally, three- 

 fourths of the cases of lameness occur in the fore-limb, and three- 

 fourths of the lameness in the fore-limb occur within a few inches of 

 the ground. The detection of the seat of lameness will ever be 

 one of the most difficult duties of the veterinary surgeon, and 

 a thorough knowledge of the anatomy and physiology of the limbs 

 is the first step towards forming a sound judgment. 



