292 SKELETON OF THE KABBIT 



separated by a great gap or diastema from the group 

 of grinding teeth in the hinder part of the mouth. 

 The rabbit has no teeth corresponding to the canine 

 teeth of other mammals. 



a. The teeth of the upper jaw. 



i. The incisors are two pairs of teeth at the front 

 of the upper jaw, lodged in alveoli in the pre- 

 maxillffi. 



a. The anterior incisors are long, and curved 

 almost into semicircles, the greater part of 

 each being lodged in an alveolus which 

 extends almost to the hinder end of the 

 bone. Along the anterior surface the 

 enamel is thick, and folded so as to form 

 a longitudinal groove. Behind and at the 

 side it is much thinner, and hence wears 

 away more rapidly, rendering the cutting 

 edge chisel-shaped. 

 /3, The posterior incisors, which are lodged in 

 alveoli immediately behind the anterior ones, 

 are much smaller, and slightly curved. 



ii. The grinding teeth form a set of six teeth on 

 each side, borne by the maxilla, and divisible 

 into two groups. 



a. The premolars are the three anterior grinders 

 of each side, and are distinguished from 

 the posterior ones by the fact that, like the 

 incisors, they are preceded in early hfe by 

 ' milk ' or deciduous teeth, which in the 

 rabbit are shed before birth. 



Each premolar is flattened from before 

 backwards, and each of the two hinder ones 

 has a deep groove along its outer surface 

 which carries the enamel almost across the 

 tooth, giving rise to a prominent ridge on 

 the grinding surface. 



