30G G. V. HAMILTON 



the cages, she would copulate with them. I had frequently 

 observed her surrounded by Mutt and the three eunuchs, copu- 

 lating with one after another. The eunuchs were more apt to 

 indulge in homosexual copulation than in copulation with the 

 female, but they were not infrequently observed cohabiting, 

 rather perfunctorily, with the female. 



For several days after Sandy's admission to the band the three 

 eunuchs screamed with rage whenever he copulated with Grace. 

 Jimmy and Mutt made no demonstration whatsoever on these 

 occasions. The eunuchs' behavior is all the more remarkable in 

 that, although they are ordinarily very timid, and especially 

 afraid of Sandy, they would pull his fur when they found him 

 copulating with Grace. 



Situation 7. Several males and females at large. Number 

 of each sex sufficient to enable each animal to have frequent 

 natural sexual relation. 



Observation 11. 16-Sobke-M-r (sexually mature), Jimmy II- 

 M-c (sexually mature), 24-Mutt-M-cr (sexually immature), 22- 

 Daddy-M-c (adult eunuch), 20-Chatters-M-c (immature eunuch), 

 18-Baby-M-c (immature eunuch) and the following sexually 

 mature females had been at large for several weeks: 11-Grace- 

 Papio — , 3-Kate-M-r, 7-Becky-M-r, 5-Maud-M-r and 9-Gertie- 

 M-cr. They wandered freely about the laboratory yard, through 

 the trees and over the tops of the laboratory and the cage. 

 During this time I was able to make a large number of observa- 

 tions, which will be summarized here, rather than given separately 

 and in detail. I found that, although Sobke dominated the band, 

 and could therefore have as frequent sexual relations with any 

 of the females as he desired, he, like all the other males, indulged 

 in homosexual relations. His case is especially interesting, 

 since he was acquired when quite small, and has spent much of 

 his time at large, in company with both males and females. I 

 cannot recall any time when he was confined without at least 

 one female companion. Nevertheless, during the time now under 

 discussion he would approach a smaller male, smack his lips and 

 mount the object of his homosexual desires with evidence of con- 

 siderable sexual excitement. He copulated with the females 

 more frequently than with the males, and his homosexual 

 behavior was of decidedly less frequent occurrence several months 

 after he arrived at sexual maturity than it was during his sexual 



