64 THE JERSEY, ALDERNEY AND GUERNSEY COW. 



which may be framed, and the exceptions are too 

 numerous to admit of accuracy in calculations. 



The age of the ox cannot be determined with so much 

 precision as that of the horse, from the diversity in the 

 precocity of different breeds, as well as the very various 

 methods of management they are subjected to. 



The obvious changes of the teeth have been divided 

 into two epochs. The first consists in the eruption and 

 wear of the temporary teeth, and the second the erup- 

 tion and wear of the permanent teeth. 



First Epoch. — There are two periods in this epoch — 

 the one from birth to thirty days, and the second up to 

 eighteen months. A calf is usually born with four 

 incisor teeth through the gums. In tardy animals the 

 four appear within the first four days, the next two about 

 the fifteenth day, and the fourth pair from the fifteenth 

 to the twenty-fifth day. The second period of the first 

 epoch consists in the wearing down of the temporary 

 teeth, which occurs successively from the centre to the 

 corner teeth, so that all are much worn by eighteen 

 months. 



Professor Simonds says, " The putting up of the tern- 

 porary incisors and molars at about a month completes 

 'first dentition;' and as there is now a given number 

 of teeth, so any addition to them will make an import- 

 ant stage in the further process of teething. When 

 this addition takes place, the temporary teeth, merely 

 by their number, cannot avail in our inquiries, nor can 

 they be said materially to do so up to that period by the 



