PHILOSOPHY OF LOVE 



CHAPTER V 



SEXUAL DIMORPHISM 



II. Vertebrates: Unnoticeable in fish, saurians, rep- 

 tiles. The Bird World. Dimorphism favourable to 

 males: the oriole, pheasants, the ruff. Peacocks and 

 turkey-cocks. Birds of paradise. Moderate dimor- 

 phism of mammifers. Effects of castration on dimor- 

 phism. 



II. VERTEBRATES. Sexual differences are generally 

 unnoticeable in fish, reptiles and saurians. They are 

 accentuated when we come to superior vertebrates, to 

 birds and mammals, but without ever attaining the ex- 

 treme difference which characterizes a great number of 

 arthropodes. In birds the disparity may be of colouring, 

 size, or length, form and curliness of the feathers; among 

 mammals, of shape, hair, beard or horns. Sometimes 

 the female bird is finer and stronger; thus stronger and 

 of more powerful wing-spread in the case of the secre- 

 tary, the buzzard, the falcon, the ash-coloured vulture 

 and many birds of prey; more beautiful as in the Indian 

 turnices. 1 One of them, the gray phalarope, solves 

 woman's dream in favour of the female, leaving her the 

 brilliant colours; the male contents himself with more 

 1 Bird, rather like quail. 



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