136 PHYSIOLOGY AT THE FARM. 



permanent, as in the ox, are fewer than in the horse. This is 

 owing, in particular, to the defect of incisor teeth in the upper 

 jaw a deficiency which belongs to ruminants in general. 

 Neither has a sheep canine teeth or tushes a deficiency which 

 also is common to ruminants in general, with the exception of 

 some of the deer tribe, as the stag and the musk-deer. As in 

 mammals generally, with the exception of man, there is a long 

 space in the lower jaw destitute of teeth namely, between 

 the incisor most distant from the centre, and the most forward 

 of the molar or back teeth. 



Like the ox, the sheep has the same number of teeth as 

 man, the number in the adult sheep being thirty-two. The 

 teeth in the sheep conform to very much the same rule as in 

 the ox. There are, in the lower jaw of the sheep, eight in- 

 cisors. This is the same number of incisors as are in man, 

 the difference being that in man there are four incisors in the 

 under jaw and four in the upper jaw, while in the sheep all the 

 eight incisors are in the under jaw. In the sheep there are 

 twenty-four back teeth or grinding teeth that is, four more 

 such teeth than man has ; but the deficiency in the sheep of 

 canine teeth, of which man has four, reduces the whole num- 

 ber of the teeth to the same number as in man namely, thirty- 

 two. The three anterior molar teeth on each side in the 

 sheep, like the two anterior molar teeth in man, having only 

 two tubercles, are termed bicuspid teeth or false .molars. 



The milk teeth in the sheep are, as in man and in the ox, 

 twenty in number namely, eight incisors in the lower jaw, or 

 the same as the number of the permanent incisors, while the 

 milk molar teeth are only three on each side of each jaw, or 

 twelve in all. The milk molars in the sheep differ from the 

 permanent molars which replace them, by being longer from 

 before backward than in the cross direction. The two central 

 incisors come out before birth, or a few days after birth, and 



