468 THE RABBIT CHAP. 



In addition to head, trunk, and short tail, the rabbit 

 possesses a distinct neck, and the whole animal, including the 

 limbs and even the soles of the feet, is covered with a soft 

 fur consisting of hairs (Fig. 121). In the wild rabbit, the 

 fur is of a brownish colour, lighter below, and white under 

 the tail : in the many domesticated varieties the colour is 

 very varied. 



The hairs correspond to modified epidermic cells, which become 

 converted into a horny material ; they are developed in tube-like involu- 

 tions of the epiderm called liair-sacs, into the swollen base of each of 

 which a mesodermal liair-papilla projects, the substance of the hair 

 being formed from the epidermic cells coverint^ the papilla. Into the 

 hair-sacs open the ducts of sebaceous glands, the secretion of which 

 serves to lubricate the hair. 



There are five digits in the hand or manus, and four in 

 the foot or pes, each terminated by a pointed and curved 

 horny claiv, developed, like the hairs, from the epiderm. 

 Along the ventral surface of the body in the female are four 

 or five pairs of papillae — the teats, on which open the ducts 

 of the milk-glands, which correspond to modified sebaceous 

 glands. The various parts of the skeleton (Fig. 121) can 

 be felt through the skin, and in addition to those already 

 enumerated in'the Vertebrates previously studied, it will be 

 noticed that the anterior part of the trunk, or thorax, is sur- 

 rounded by ribs, many of which meet below with a breast-bone 

 or sternum, and which are absent in the posterior part of 

 the trunk, or ahdmnen. 



Beneath the anterior end of the snout is the transverse 

 mouth which has a narrow gape and is bounded by upper 

 and lower lips : the upper lip is divided by a longitudinal 

 cleft which is continuous with the oblique, slit-like external 

 nostrils. Just inside the lips are the upper and lower front 

 teeth oxincisors,y<\\vz\i are chisel-shaped, and behind them the 



