XXVIII 

 THE RED TURTLE DOVE 



INSECTS and birds, on account of the vast 

 number of species they present, furnish the 

 best available material for the study of evo- 

 lution. It is owing to the fact that most Pro- 

 fessors of Zoology are neither entomologists nor 

 ornithologists that biological science is in its present 

 deplorably backward condition. There exists scarcely 

 a zoological theory, be it neo-Lamarckian or neo- 

 Darwinian, that the competent ornithologist is not 

 able to refute. For example, writing of sexual di- 

 morphism in animals, Cunningham states that in the 

 case of birds which exhibit such dimorphism the cocks 

 differ essentially in habits from the hens, and in 

 this way he, as a Lamarckian, would account for 

 their external differences. " The cocks of common 

 fowls and of the Phasianidce generally," he writes, 

 " are polygamous, fight with each other for the posses- 

 sion of females, and take no part in incubation or 

 care of the young, and they differ from the hens in 

 their enlarged brilliant plumage, spurs on the legs, 

 and combs, wattles, or other excrescences on the head. 

 In the Columbida, per contra, the males are not poly- 



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