MAMMALIA. 269 



white membrane, usually folded up in the anterior angle of the 

 eye. The auditory aperture on each side is situated some distance 

 behind the eye, and is guarded by a long backwardly and up- 

 wardly directed flap, the pinna, the base of which is supported by 

 cartilage. 



The pinna varies very much in size and position in tame rabbits, 

 especially in lop-eared varieties. 



The short neck forms a connecting region between head and 

 trunk. 



The trunk is somewhat flattened from side to side. It i& 

 divided into a relatively small thorax in front, bounded by hard 

 parts, and a large soft-walled abdomen behind. There are, in the 

 fei mile, five to six pairs of teats on the ventral surface, belonging 

 to the milk glands (mammary glands). Upon each teat are the 

 small openings of the corresponding gland. 



The intestine and urinogenital organs here open separately to 

 the exterior, the former by a rounded anus situated immediately 

 beneath the tail, and the latter by an urinogenital aperture, placed 

 a, little further forwards, and varying in character according to 

 sex. The space between the anus and urinogenital aperture is 

 known as the perineum, and on each side of this there is a bare, 

 pouch-like depression, the perineal space, upon which is a small 

 papilla bearing the aperture of a perineal gland, to the secretion 

 of which the unpleasant odour of rabbits is due. 



The tail is short, but distinct. 



The fore-limb is divided into upper arm, fore-arm, and hand 

 (brachium, antebracldum, and maims}. The much longer hind-limb 

 is divided into thigh, leg, and foot (femur, cms, and pes). The 

 digits are clawed, five in number in the hand, four in the 

 foot. 



Position of Body. In the standing posture the elbow i& 

 directed backwards, the knee forwards, and the ankle-joint back- 

 wards. Both limbs are disposed in longitudinal vertical planes r 

 and the body is lifted well off the ground. 



2. The thick skin is made up of epidermis and dermis, the hairs- 

 being developments of the former. The mammary and perineal 

 glands belong to the skin, and they are imbedded in the under- 

 lying, subcutaneous, connective tissue, which is everywhere abun- 

 dantly present. Beneath and closely connected with this is a 



