138 THE STKUCTUKE OF THE HOESE. 



The canine teeth of the horse evidently belong to 

 the permanent set, not coming into place until the 

 animal is full grown, and lasting throughout its 

 lifetime. It is commonly stated that they have 

 no deciduous predecessors. On this subject, how- 

 ever, the following observations of Lecoq are impor- 

 tant :* 



" The canine teeth are not shed, and grow but once. 

 Some veterinarians, and among them Forthomme and 

 Rigot, have witnessed instances in which they were 

 replaced ; but the very rare exceptions cannot make 

 us look upon these teeth as liable to be renewed. 

 We must not, however, confound with these excep- 

 tional cases the shedding of a small spiculum, or 

 point, which, in the majority of horses, precedes the 

 eruption of the real tusks." 



These spicules are in all probability the true 

 milk canines in an extremely vestigial condition; 

 their loss, in the gradual process of degeneration of 

 these teeth, taking place, as might be expected, be- 

 fore that of their permanent successors. This sub- 

 ject would well repay a fuller investigation than it has 

 hitherto met with, as it seems to be another of the 

 numerous instances of rudimentary structures in the 



* Quoted in Fleming's translation of Chauveau and Ar- 

 loing's Comparative Anatomy of the Domesticated Animals 

 (1873), p. 352. 



