MAMMALIA 



639 



completely destroyed. With proper protection, however, these 

 species might still be restored iu many parts of the country. Squir- 

 rels and rabbits are the most abundant game mammals of present 

 times. 



THE CAT, A REPRESENTATIVE MAM3VLAL 



The common house cat, Felis domestica, is a carnivore which is 

 familiar to everyone. It is so common that it is always available for 

 study. The cat is a quadruped which is well adapted for walking 

 and climbing, at which activities it is very adept. The eyes of the cat 

 are well adapted to sight at night when it is quite active. As a result 

 of domestication the carnivorous diet of the cat has been somewhat 

 modified. The cat is clean in its sanitary habits. 



External Structure 



The entire body is covered with a high quality hair or fur which 

 may be one of several colors. On the upper lip and around the eyes 

 are some especially long stout hairs, whiskers or vibrissas. The upper 

 lip is somewhat cleft in the center. In the hare this cleft is extremely 

 prominent, and it is from this that the abnormally cleft lip in man 

 came to be known as ''harelip." The tall, flexible external ear or 

 pinna partially surrounds an ear opening, the external auditory 

 meatus, which leads to the interior of the skull and the tympanic 

 membrane. The large, oblong nostrils are located in the fleshy nose, 

 the end of which is naked. Their large eyes have both upper and 

 lower lids, and each has a sheetlike nictitating membrane which may 

 be drawn over the eye from the medial corner. 



The trunk is conveniently divided into a thorax or chest, supported 

 by the ribs, and posterior to this the abdomen. Extending posteriorly 

 is the long slender tail. Along the ventral side are four or five pairs 

 of nipples or teats which are prominent in the female but rudimen- 

 tary in the male. They contain the openings of the milk or mammary 

 glands. Ventral to the tail is the perineal region in which is located 

 the anus and external genital organs. The two pairs of limbs extend 

 ventrally from the sides of the trunk. The forelimb is divided into 

 upper arm, forearm, wrist, palm, and five digits with retractile 

 claws at their tips. The hindlimb extends from the hip and is divided 

 into thigh, shank, ankle, arch, and four digits with similar claws. 



