HORMONES AND MATING BEHAVIOR 



1197 



quence following the implantation of pellets 

 of testosterone propionate into female 

 Xiphophorus hellen (Noble and Borne, 

 1941), a species which has long been known 

 to undergo spontaneous sex reversal from 

 female to male (Essenberg, 1925). The 

 change is less pronounced in adult female 

 platyfish given methyl testosterone; they 

 exhibited the first phase of courtship be- 

 havior, but precopulatory and copulatory 

 behavior w^ere not seen (Laskowski, 1953). 

 Female lizards given pellets of testosterone 

 propionate displayed courtship behavior 

 and went through the complete male copu- 

 latory pattern (Noble and Greenberg, 

 1941b). Injections of large amounts of tes- 

 tosterone propionate induced male behavior 

 in adult and immature female black- 

 crowned night herons. Smaller ciuantities 

 induced female behavior and estrogens ap- 

 pear to have been without effect except on 

 the genital tract (Noble and Wurm, 1940a). 

 Female canaries sang following injections 

 of testosterone propionate (Leonard, 1939) 

 and also exhibited posturing and pairing 

 characteristics of males, but they did not 

 tread receptive females (Shoemaker, 1939). 

 Free-living valley quail containing pellets 

 of testosterone propionate assumed the male 

 role without copulating. Their reactions 

 were described as being slower and weaker 

 than those of males given the hormone 

 (Emlen and Lorenz, 1942). The same hor- 

 mone did not induce male behavior in fe- 

 male herring gulls (Boss, 1943). The ad- 

 ministration of androgen to intact hens 

 (Hamilton and Golden, 1939), ovariec- 

 tomized poulards (Davis and Domm, 1941), 

 and to ovariectomized pullets (Davis and 

 Domm, 1943) was followed by crowing and 

 some "waltzing," but no copulatory be- 

 havior. The latter was observed in 3 of 24 

 brown leghorn pullets some of which were 

 observed 4 years (Domm and Blivaiss, 

 1947), and in 1 of 2 white Leghorn hens 

 several months after the implantation of 

 pellets of testosterone propionate (Zitrin, 

 1942). A regimen of 500 mg. testosterone 

 l)roi)ionate per day into female chicks stim- 

 ulated comb and wattle growth, but no 

 crowing, wing-flapping, or other cock-like 

 attitudes occurred during the 55 days they 

 were observed (Hamilton, 1938) . In another 



expriment crowing, described as a short, 

 feeble, high-pitched squeak which lasted 

 about a second, was observed in 10 of 75 

 female chicks containing pellets of testos- 

 terone or given oil solutions (Hamilton and 

 Golden, 1939). The crowing behavior dis- 

 appeared frequently after the 1st week 

 and almost completely by the 4th week, 

 although the comb showed a continued re- 

 sponse to androgen. 



An intersexed mouse whose usual be- 

 havior was that of a female displayed the 

 copulatory pattern of the male when in- 

 jected with large doses of testosterone pro- 

 pionate (Raynaud, 1938). Except for this 

 somewhat ambiguous case, masculinization 

 of a female mammal by the use of purified 

 androgenic substances seems first to have 

 been achieved by Hu and Frazier (1939). 

 Adult female rabbits injected 6 days a 

 week with 1 mg. testosterone propionate for 

 21 to 32 days displayed vigorous masculine 

 behavior which persisted after the injections 

 until the external genitalia had returned 

 to the female type. The female rabbits into 

 which Klein (1952) implanted pellets of 

 testosterone propionate or acetate displayed 

 "quite a typical" male behavior, provided 

 they were with other females. As we have 

 noted (p. 1196), feminine responses were ex- 

 hibited when they were in the presence of 

 males. When 100 mg. testosterone propionate 

 were administered to anestrous female sheep 

 3 days before PMS was given they mounted 

 other females (Cole, Hart and Miller, 1945) , 

 but the authors note that such animals were 

 also subject to their own estrogen and pro- 

 gesterone as well as to exogenous androgen. 

 Mounting behavior and aggressiveness were 

 displayed by 3 intact and 3 ovariectomized 

 dairy heifers receiving 25 mg. testosterone 

 propionate daily (Gassner, 1952). In this 

 work the behavior displayed by the ovariec- 

 tomized animals could not be ascribed to the 

 presence of functioning follicles. 



An increase in the amount and strength 

 of masculine behavior followed the injection 

 of testosterone propionate into intact (Ball. 

 1940) and spayed female rats (Beach, 

 1942b). Ball injected 2 mg. twice a week 

 following a 3-week period when half this 

 amount had been given. She regarded the 

 reactions as definitive but also as somewhat 



