THEIR PHYSIOLOGICAL RELATIONS. 85 



Surgeon J. H. Winter, the author of a work entitled 

 " On the Horse," says : 



" It is difficult to assign their use. Their position 

 precludes the possibility of their being used as weapons 

 of offense or defense. They may be viewed as a link 

 of uniformity so commonly traced in the animated 

 world." 



Prof. William Percivall says that the cutting of the 

 tushes causes the constitution more derangement than 

 all the other teeth, and Prof. Youatt and other high 

 authorities entertain similar views. The present chap- 

 ter, therefore, is a proper one in which to discuss " the 

 effects of dentition on the system generally." The 

 discussion of the subject is left to well-known men. 

 Messrs. Youatt and Percivall were many years ago the 

 editors of "The Veterinarian," but their books are 

 probably the best monuments to their memory. Prof. 

 William Williams is the President of the Edinburgh 

 Veterinary College. Prof. Youatt says (" The Horse," 

 p. 230): 



" This is the proper place to speak of the effect of 

 dentition on the system generally. Horsemen in gen- 

 eral think too lightly of it, and they scarcely dream of 

 the animal suffering to any considerable degree, or 



growth of the teeth may perhaps be accounted for on the prin- 

 ciple of correlation of growth, external agencies acting on the 

 skin, and so indirectly influencing the teeth." 



A strictly analogous result might or might not follow in the 

 case of the horse. If so, the tushes would probably be used as 

 weapons of offense and defense. It is reasonable to suppose that 

 they were so used by the early progenitors of the horse, whose 

 large tushes are described in the succeeding chapter by Prof. 

 Marsh. 



