THE CHARACTERS FURNISHED BY THE TEETH. 651 



the gums ; their anterior border commences to wear, but only on its 

 internal part, which alone comes in contact with the corresponding 

 superior teeth. (Plate V.) 



About Five Months. — The eruption of the pincers is complete ; 

 the intermediates touch by the whole extent of their anterior border ; 

 the mucous membrane behind these teeth is sometimes sensitive, in 

 consequence of the presence of the corner tooth, which is at the point 

 of piercing the gums. (Plate VI.) 



About Six Months. — The intermediates are more prominent ; 

 their posterior border commences to wear. The mucous membrane, in 

 the region of the corner, is tumefied and vascular ; sometimes, even, the 

 anterior border of this tooth has pierced it very close to and behind the 

 intermediate. 



Eight to Ten Months. — The corner is ordinarily visible by its 

 anterior border only, but more or less slowly according to the subjects. 

 As to the intermediates, they are well emerged from the gums, which 

 are at the level of their necks. The inferior incisive arcade forms an 

 almost regular semicircle. (Plate VII.) 



It is impossible to pass, with precision, deeper into the details, 

 diverse causes being susceptible of influencing the eruption of the teeth 

 and their wear. Some subjects are strong and vigorous, others are 

 delicate. The nourishment also may have been more or less abundant. 

 Finally, it is certain, although it may not always be possible to appre- 

 ciate the reason, that, all things being equal, there are some animals 

 more precocious than others. 



At the commencement of the first period of life the foal is nour- 

 ished by the milk of its mother ; the wear of its teeth, but little 

 marked, is due only to their simple apposition, — to their contact with 

 the superiors ; it is only at a later period that the animal commences 

 to consume tlie fibrous and resisting aliments, and that its incisors 

 become more blunt. However this may be, the wear will be more pro- 

 nounced upon the pincers, whose eruption took place first. It will be 

 the same, in each tooth, with the anterior border as compared with the 

 posterior. 



• Besides, after the supposed epoch of birth, it is not very difficult 

 to judge, almost exactly, the age of the young subject, which, in most 

 instances, is still suckling its mother. It is at the end of this time, 

 which continues eight, nine, or ten months, that the animal, in certain 

 localities, is sold, as we have seen in Brittany, and taken into districts 

 where the food is more abundant, and where, especially, he is reared 

 with a view of utilizing him for work and preparing him for sale. 



