SECONDARY SEXUAL CHARACTERS 



111 



those of the humming-birds ; we forget the zebras, 

 the leopards ; the iridescent interiors of the shells of 

 many moUusks ; the bright reds and purples of starfish, 

 worms, corals, sea anemones, the red, yellow, and green 

 sponges, and the kaleidoscopic effect of the microscopic 

 radiolarians ; — a brilliant array of color. 



Fig. 59. — (A), female of a copepod, Calocalanus plumulosus. (B), a female 

 of Calocalanus parvus. (C), male of last. (After Giesbrecht.) 



In the egret both males and females have remark- 

 able nuptial plumes, which, had they been present in 

 one sex alone, would have been classified as secondary 

 sexual characters. It does not appear that selection 

 had anything to do with their creation. 



Our common screech owl exists in two colored types 

 sharply separated. No one is likely to ascribe these 

 differences to sexual selection, yet if one sex had been 



