Davis and Domm 



175 



Summary of Data on Various Types of I>fjECTio>f {Continued) 



* C, capon; R, rooster: BP, bilaterally ovariectomized poulard; SP, sinistrally ovariectomized poulard. 



t Date of final operation. Except in sinistral poulards, castrations were performed in two operations. 



X Experiments performed from June to November 1941. 



§ The bilaterally ovariectomized poulards used in this experiment are the same ones as were previously used in 

 the above experiment on the effect of androgen in bilaterals. An interval of approximately one month elapsed between 

 the two experiments. 



4. The Effect of Androgen in Bilaterally Ovariectomized Poulards. A bilater- 

 ally ovariectomized poulard is one in which the left ovary has been completely 

 removed following or preceding the complete removal or destruction of the 

 right rtidimentary gonad. Such individuals are, therefore, gonadless and re- 

 semble the capon in many important respects. Like the capon they are 

 neutral in behavior (Domm^'^). 



Under the influence of androgen bilaterally ovariectomized poulards be- 

 came very aggressive and fought violently. The birds were first ob,served at- 

 tempting to crow on the sixteenth day of injection. They began to crow in a 

 perfect manner a few days later and continued to do so throughout the experi- 

 ments. Within three weeks all three poulards "waltzed" at introduced females 

 or the dummy. The "waltzing," although not as vigorous as that of a male, was 

 nevertheless identical in behavior pattern. These three poulards, however, 

 did not copulate with receptive females or the dummy at any time, even 

 though the experiments were continued for sixty days. The poulards gave all 

 females as well as the dummy vicious pecks about the head, even after a 

 "waltz." Females which squatted perfectly, thereby inviting copulation, were 

 often injured by the violence of these pecks. 



5. The Effect of Androgen in Sinistrally Ovariectomized Poulards. Sinistrally 

 ovariectomized poulards are individuals in which the left ovary only has been 

 removed. Following this operation the rudimentary right gonad undergoes 

 hypertrophy, usually developing into a tcstis-like organ whose secretions are 

 mixed, having both androgenic and estrogenic effects (Lillie'). The androgenic 



