GONADAL HORMONES AND SOCIAL BEHAVIOR 



1259 



TABLE 20.1 

 The effect of androgenic treatment on the development of peck-rights in caponized chicks as compared with 

 normal cockerels and capons of the same age 

 Arrows indicate deviations from a straight-line peck-order. 



Number 

 Pecked 



Weeks of Age 



Normal males 



Androgen-treated capons, 10th day to 63rd day 



45 



GB 

 GV 



B 

 ^ R 

 VB, 



Y 

 BB-^ 



V 

 GR 

 VY 



Total 



Capons 



riod, but contraction and expansion were 

 controlled by the nervous system. The 

 bright red markings of Hemichromis were 

 also shown only when the fish engaged in 

 courtship. The reproductive colors function 

 in fighting displays and in territoriality dur- 

 ing the breeding season. Nonterritorial fish 

 were pale, and individuals crossing terri- 

 torial boundaries were not molested if their 



chromatophores were contracted. It was 

 suggested that the development of these 

 chromatophores probably is under the con- 

 trol of the pituitary. 



Noble and Curtis (1939) found that ripe 

 females of Hemichromis himaculatus se- 

 lected bright red males when given a choice 

 among females and males in different stages 

 of maturity. Tests by Tinbergen (1951, p. 



