486 THE RABBIT CHAP. 



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 integu- 

 mentary glands. The various parts of the skeleton (Fig. 130) 

 can be felt through the skin, and it will be noticed that the 

 anterior part of the trunk, or thorax, is surrounded 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 

 abdomen. 



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 or incisors, which are chisel-shaped, and behind them the 

 hairy integument is continued on either side into the cavity 

 of the mouth. The eyes are protected by movable hairy 

 upper and lower eyelids, as well as by a hairless third eye- 

 lid or nictitating membrane (compare p. 5), supported by 

 cartilage and situated in the anterior corner of the eye, over 

 which it can be partly drawn : it corresponds to the little 

 red lump in the inner corner of the human eye. On the 

 upper lip and above and below the eye are certain very long 

 and stiff hairs the " whiskers " or vibrissce, and behind the 

 eyes are a pair of long and movable external ears or pinna : 

 these are supported by cartilage and are somewhat spout- 

 shaped, leading to the external auditory openings. 



Below the root of the tail is the anus, and in front of 

 and below this the urinogenital aperture, the space between 

 them being known as the perinceum. On either side of these 

 apertures is a hairless depression of the skin on which open 

 the ducts of t\\e perinaal glands, the secretion of which has 

 a strong and characteristic odour. In the female the slit- 



