288 ZOOTOMY. 



117. In the adult male, a pair of considerable projections 

 will be seen, one on either side of the root of the penis ; 

 these are the scrotal sacs, and contain the testes. 



1 1 8. The scapula, a large bone, attached to the rest of 

 the skeleton only by muscle, can be felt through the skin in 

 the an tero- dorsal region of each side of the thorax. 



119. The division of the fore-limb into upper-arm 

 or brachium (almost hidden by the skin), fore-arm or 

 antebrachium, and hand or manus, the latter provided 

 with five clawed digits : of these the innermost or pre-axial 

 digit is distinguished as the thumb or pollex. 



120. The division of the hind-limb into thigh or 

 femur (almost hidden in the skin), shank or >crus, and 

 foot or pes, the latter very long, and terminated by four 

 clawed digits : the innermost of these corresponds with the 

 index, the true first digit or hallux being absent. 



121. In the female, the teats of the four or five pairs of 

 mammary glands are seen, about two inches apart, on 

 either side of the middle ventral line of the body : the 

 anterior pair is thoracic, and occurs at about the junc- 

 tion of the anterior and middle thirds of the thorax : the 

 remaining three pairs are abdominal in position. 



XII. Fix the animal in the supine position, i.e., with 

 the ventral surface upwards ; make a longitudinal 

 incision into the skin over the sternum, and 

 continue the cut forwards to the mandibular 

 symphysis and backwards to the pubic symphysis. 

 With the handle of a scalpel, carefully separate 

 the skin from the underlying parts over the whole 

 ventral surface. Note : 



122. A thin sheet of muscle the panniculus car- 

 nosus, or cutaneous muscle lying immediately beneath 

 the skin, to which it is closely attached, and covering the 



