COLLABORATOR OF DARWIN 109 



the male of such a pair of young is a blue and 

 the female a silver ; also, that if the young are 

 both silvers they are almost certain to be hens. 

 Tegetmeier adds that: "It is a singular circum- 

 stance that Mr. Darwin should have suggested 

 the possibility of modifying the sexual colours 

 of birds by a course of artificial selection. When 

 he did so he was in ignorance of these facts that 

 I have related ; but it is remarkable how very 

 closely he suggested the right methods of pro- 

 cedure." Darwin quoted this in the second 

 edition of The Descent of Man, glad as he always 

 was to receive the support of one whose prac- 

 tical knowledge and independent investigations 

 had made his help so valuable. 



It was Tegetmeier's privilege on many occasions 

 to put the great naturalist right on points with 

 w r hich he was the better acquainted. For 

 instance, we find Darwin writing to inquire 

 whether the loss of sexual adornments, tail sickle 

 feathers and saddle feathers, renders the game- 

 cock less acceptable in the sight of the hen birds. 

 It was a reasonable assumption that they would 

 lose in attraction, and Darwin's own views on the 

 subject of sexual adornment are set out at length 

 in The Descent of Man* ; but Tegetmeier, from 

 his knowledge of game-fowl, was able to assure 

 him that in this case at least the cock lost nothing 

 in attractiveness ; that although disfigured by 



* See Chapter XIII., " Display by the Male." 



