766 THE EXTERIOR OF THE HORSE. 



months at the most, and sometimes not at all ; in the second case, from 

 fifteen to thirty days. 



" It would be a gmve error to believe that by pulling the interme- 

 diates at the time of the natural shedding of the pincers the former 

 would, at the end of some days, be pushed out on a level with the lat- 

 ter. The wound resulting from the operation on these teeth would, on 

 the contrary, cicatrize very promptly, and form, at these places, a strong 

 and quite persistent pad. 



" As I liave said above," adds M. Yvon, " I think that the extraction 

 of the teeth advances the dental evolution but little. On the posterior 

 face of each milk-tooth which is shed it is easy to notice a deep con- 

 cavity, a veritable imprint made by the permanent tooth, whicli incrusts 

 itself here by pushing the former out of its alveolus. It is evident 

 that it is not the milk-tooth, which must fall out, that prevents the 

 eruption of the permanent one, but rather this latter which pushes out 

 the other one in proportion as it is developed. 



"Our Norman colts, with a few exceptions, are born from the 15th 

 of February to the 15th of June. There is therefore a diiference of 

 four months between these two extreme periods. In the month of 

 January, five years after their birth, the colts born in February may 

 have all their incisors, while in the others the evolution of the corners 

 will not have taken place until the month of May. Nevertheless, all 

 these colts will be considered as five years old, although those born in 

 May or in June may not have all their teeth. To do away with the 

 dental differences from this variation in time, breeders very often ex- 

 tract at four and a half years the corners of colts born in June, in 

 order to make them mark five years, like those of February of the 

 same year. 



" Under other conditions, breeders extract at four and one-half 

 years the corners of horses foaled at the commencement of the year, and 

 their permanent corners having gradually acquired their normal length 

 in January and February after their fifth year, they may pass them on 

 ignorant persons for horses six years old." 



The removal of the milk incisors has no influence upon the general 

 development of the animal on which the operation is performed. 



Finally, it must be concluded, after all the information given, that 

 the extraction of these teeth quickens in a certain proportion the erup- 

 tion of the permanent ones, and apparently makes tli£ animal older, 

 especially if the operation has been done a short time before the natural 

 fall of the milk-teeth. In this case a horse which marks five years 

 has, therefore, really not acquired this age. 



