248 Descriptive Zoology. 



dens and orchards. The rabbit likes such places, not only 

 on account of the food there found, but also because of the 

 shelter afforded by the grass and bushes. In winter, when 

 fresh vegetation is scarce, the rabbit eats twigs, especially 

 the buds and bark ; thus a brush heap of fresh cuttings 

 from such trees as the apple affords the rabbit both shel- 

 ter and food. 



The Rabbit's Teeth. At the front of the mouth are 

 two pairs of chisel-shaped teeth, the incisors. These teeth 

 are mainly composed of dentine. On their front surfaces is 

 a layer of hard enamel. The result of this hard front edge 

 is that in gnawing, the hinder edges of the teeth are worn 

 away faster and the teeth are kept constantly beveled ; in 

 other words, they are self-sharpening. These teeth grow 

 at the base of the roots as fast as they are worn away at 

 the outer ends. If one of these teeth should be broken 

 off, or otherwise destroyed, the opposing tooth would no 

 longer be worn down and would grow too long, and sooner 

 or later interfere with the process of eating and cause 

 starvation. Many cases of this kind among rodents have 

 been known. Back of the upper incisors is another, smaller 

 pair of teeth, also regarded as incisors, an arrangement pe- 

 culiar to the rabbits and not found in other rodents. Back 

 of the incisors is a considerable space without any teeth, 

 before the grinding teeth, or molars, are reached. This 

 space undoubtedly enables the rabbit to manage the mouth 

 better in gnawing, just as in most of our pinchers we have 

 a widened space back of the nipping jaws. The same 

 arrangement is found in the horse, cow, etc. 



The molars are six above and five below, set in close 

 rows, and having ridges running crosswise. The direction 

 of these ridges must be considered in relation to the joint 

 by which the lower jaw articulates with the skull. This 



