SEXUAL BEHAVIOR OF ALBINO RAT 145 



had never before been with an animal other than his kind, he 

 approached the guinea-pig without fear. The latter was moder- 

 ately tame, but ran from the rat when he touched her while 

 nosing about. In a short tune he began smelling and nosing in 

 the vaginal region whereupon the young guinea-pig ran away; 

 but the young male did not pursue at this tune. They were left 

 together in the cage for one hour with no signs of sexual excite- 

 ment on the part of the male. Three hours later, the same 

 guinea-pig was returned to the cage of the rat. As in the pre- 

 vious instance, the latter soon began nibbling and smelling and 

 as before, she darted away when he touched the sensitive regions 

 about the vagina. Gradually after numerous repetitions of the 

 smelling and the female's running away the male began to mani- 

 fest signs of sexual excitement. Eventually he pursued and 

 attempted to mount her as she darted forward. Mounting 

 attempts more vigorous and persistent followed, and before the 

 period of observation ended he was seen on several occasions in 

 hot pursuit of the guinea-pig with his fore-paws clasping her 

 sides and leaping along behind her on his hind feet as she darted 

 about the cage. Subsequent trials resulted in a repetition of the 

 foregoing behavior. Copulation was not observed. 



To summarize the foregoing preliminary experiments it may 

 be said that the following objects are adequate to evoke the 

 copulatory act in an inexperienced male which has reached the 

 proper state of physiological development: an active female in 

 heat, and a female not in heat which has been made to respond 

 to his exploratory activity by quick movements resembling those 

 of a female in heat. Sexual excitement was aroused followed by 

 partial attempts at copulation by a small guinea-pig which moves 

 about the cage in a manner somewhat resembling that of the 

 female in heat. 



GENERAL REMARKS 



The scope of this study is limited to an account of the copula- 

 tory pattern and its activation. Data bearing on the internal 

 factors which condition the response will be presented in a sub- 

 sequent paper. In its present stage of completion this investi- 



COMPABATIVE PSYCHOLOGY, VOL. II, NO. 2 



