104 CALVIN P. STONE 



ported on the root of the tail and toes of the hind feet. At the 

 same time the mouth is brought down to the penis which is still 

 in a semi-erect condition. Vigorous licking of the organ follows. 

 After a few seconds licking the organ becomes flacid and is re- 

 tracted into its sheath and the male comes to a position of rest 

 on all fours where he remains quietly for a short time or engages 

 in minor activities such as nibbling at parasites, scratching the 

 body, or sniffing warily at the female. Smelling and licking in 

 the vaginal zone is seldom repeated after the first two or three 

 copulatory acts. 



By way of summarization of the foregoing description the 

 overt pattern of the copulatory act may be broken up into the 

 following elementary acts or groups of activities: 



1. Pursuit and mounting. 



2. Palpation of the female's sides. 



3. On the part of the female, depression of the lumbar region 

 of the back with consequent elevation of the sacro-coccygeal 

 region. 



4. Pelvic movements of the male by which the penis is thrust 

 toward the vagina in piston-like manner. 



5. Cessation of palpation of female's sides and the backward 

 lunge. 



6. Licking of the penis. 



The duration of the complete act, from the time of the initial 

 clasp to the backward lunge is usually only a fraction of a second. 

 The time is so brief that one cannot measure it accurately with 

 a stop-watch. In each instance of its appearance, the pattern 

 is strikingly uniform, yet close observation reveals some minor 

 irregularities. A few of these are deserving of mention. 



Piston movements by which vaginal entrance is effected do 

 not invariably follow palpation. Sometimes, apparently, this 

 is due to failure in eliciting coccygeal elevation on the part of 

 the female, but again it seems to be due to failure of erection. 

 Evidence of the latter is seen most frequently during a long series 

 of copulations. The number of such instances increases with 

 the number of copulations. 



