THE BEAD AND NECK 



120 



animal is full grown, and lasting throughout its lifetime. 

 It is commonly stated that they have no deciduous pre- 

 decessors. On this subject, however, the following 

 observations of Lecoq are important 1 : — 



4 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 exceptional 

 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, before that of their 

 permanent successors. This subject 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 horse, pointing to a 

 different condition in the ancestral state. 



The diminutive first premolars should probably be 

 regarded as teeth of the permanent set, and, considering 

 how near they are to disappearance, they could hardly 



1 Quoted in Fleming's translation of Chauveau and Arloing's 

 Comparative Anatomy of the Domesticated Animals (1873), p. 352. 



K 



