SEXUAL BEHAVIOR OF ALBINO RAT 121 



which enables him to guard against the attack of the aggressor 

 and indicates to the latter that no counter attack from him is to 

 be expected. Sometimes after the adult ceases pummeling the 

 young animal, the latter holds the defense pose for several min- 

 utes (Posing , tables 2 to 11). Particular attention is called to 

 the amount of posing done by the young animals in company 

 with adult males (tables 2 and 3). Contrast with tables 4 and 

 5. The adults show increased tendency to maltreat the young 

 after the latter have reached the age of forty to fifty days 

 (tables 3 and 5). Item 16 which is another phase of the defense 

 response, characterized by cautiously avoiding the adult, shows 

 that the attacks of the adult cause responses which carry over 

 from day to day. Not infrequently the young animals showed 

 this fear response, although no attack on the part of the adult 

 had been made or threatened during that period. 



Wrestling is initiated both by the adult and by the young. It 

 was an activity of daily occurrence in the case of the first group 

 of twenty-three animals; they were allowed to mingle together 

 while not in the cages for observation. The eight animals of the 

 second group, which were reared in almost total isolation seldom 

 attempted to wrestle with the females. It appears that this 

 activity acquires the characteristics commonly seen in the play 

 of young rats only through experience. 



The amount of time spent in following closely behind the adult 

 without actually smelling or nibbling depends somewhat upon 

 the general activity of the adult. Most animals continue their 

 smelling and nibbling while the adult moves about the cage, 

 but occasionally one follows without actually touching the adult's 

 body. 



In a subsequent chapter the purpose of the experiment in- 

 volving the placing of a weak solution of pituric acid on the left 

 elbow of the female will be discussed at greater length. Atten- 

 tion is called at this place to the fact that all young animals 

 discovered the oderiferous substance at once. The amount of 

 smelling in this region greatly exceeded that of the vaginal zone 

 for several days, but gradually the amount ceased to increase 

 and eventually decreased; finally this region was not smelled 



