SEXUAL BEHAVIOR OF ALBINO RAT 129 



1. Both males and females devote the greater part of their 

 time to the performance of activities that have no relation to the 

 sexual act. 



2. Both males and females smell the ano-vaginal zone. This 

 may be begun as early as the twenty-first day of age. The smell- 

 ing increases from day to day until the age of thirty-five to 

 forty days is reached, but thereafter the amount remains fairly 

 constant. Toward the end of the pre-mature period the amount 

 of smelling is decreased in the case of some males because of fear 

 of the adults. On the whole the young males smell slightly more 

 than the females. 



3. Young males lick their external genitals more than young 

 females. At first the males lick only the sheath, but eventually 

 the licking is directed largely to the glans penis. 



4. Copulatory attempts were not made prior to the age when 

 sexual maturity is near at hand (sixty days or over). No play 

 activities of a sexual nature approximating those of the true 

 copulatory act were seen at any time. Observations on approx- 

 imately fifty young males failed to reveal sexual play such as 

 that referred to by Small ('99) in the case of rats under thirty 

 days of age. 



5. Pursuit does not in the early age serve a sexual end. 



6. The animals discovered the odoriferous substances placed 

 on the right elbow of the female on the first day it was placed 

 there (twenty-three to twenty-four days of age). They respond 

 to this odor in much the same way as they do to vaginal odors 

 at the outset. Gradually they cease or decrease the amount of 

 smelling of this odor. 



7. Sexual excitement does not occur when a receptive female 

 is placed with a young male until the age at which copulatory 

 ability is near at hand (approximately sixty days of age or later). 



8. The elementary activities of the copulatory pattern in the 

 young male are generally well coordinated at the tune of the 

 first copulatory act. In essential detail the act as a whole re- 

 sembles that of the experienced male. 



9. Somatic sexual maturity as indicated by the presence of 

 free spermatizoa in the reproductive tract does not coincide 



