Davis and Domm ^^^ 



other females. In contrast, those receiving androgen definitely noticed the 

 dummy and reacted toward it in much the same way they reacted toward 

 normal hens. 



Discussion 



The action of androgens and estrogens in the control of behavior has been 

 studied in few species. In the domestic fowl it has been repeatedly shown that 

 testosterone will produce crowing in both males (Benoit') and females (Allee, 

 CoUias and Lutherman"; Hamilton and Golden'"). It is important to note 

 that these females did not copulate. In young male chicks Hamilton"^ produced 

 crowing at ten days of age although the females did not crow in fifty-five days. 

 Later Hamilton and Dorfman"^ caused male chicks to crow sixty hours after 

 hatching. In addition, Allee, Collias and Lutherman" observed crowing in 

 four-month-old pullets. These authors also noted a somewhat abbreviated 

 "waltz" or courtship pattern in two of their females. By stimulating develop- 

 ment of gonads precociously with pituitary hebin, Domm and Van Dyke"" 

 and Domm'^ observed crowing in young cockerels at nine days of age and 

 treading at thirteen days. These authors observed little if any effect on the 

 behavior of similarly treated young pullets even though there was sufficient 

 androgen produced, by the hypertrophied medullary component of the left 

 ovary, to bring about masculinization of head furnishings comparable to that 

 of treated cockerels. In female canaries Leonard" induced singing by injection 

 of testosterone and Shoemaker" thus produced singing and covirtship behavior 

 as wtII as an increased aggressiveness, but no copulations. In nondomesticated 

 birds Noble and Wurm'* found that in the black-crowned night heron testost- 

 erone will induce masculine sexual behavior in adult females and even in 

 month-old chicks. The patterns consisted of territory defense, nest building, 

 courtship ceremonies, and copulation on one occasion. In the laughing gull 

 Noble and Wurm" found that testosterone produces those behaviors common 

 to both sexes as well as those of the male. In mammals under the influence of 

 testosterone BalP found that female rats performed masculine copulatory 

 patterns and Beach"' observed that male rats performed female mating 

 behavior. The latter author concluded that the stimulus situation is the 

 selective factor that determines which type of response will be manifested 

 under the conditions of great excitability produced by testosterone. Similarly 

 in the lizard Aiiolis carolinensis, Noble and Greenberg" found that testoster- 

 one elicits both male and female behavior. Evans,^"' studying Anolis carolin- 

 ejisis, found that female lizards which had been castrated fought much more 

 than normal individuals and that the injection of ovarian hormone inhibited 

 the fighting. 



The effect of estrogen on behavior is less striking. In chickens Allee and 

 Collias^ found that one poulard, sinistrally ovariectomized by L. V. Domm, 

 squatted under the influence of estrogen. Noble and Wurm'* found that no 

 behavior of the female black-crowned night heron is due to estrogen. These 

 authors also found" that the injection of estrogen into either sex of the laugh- 



