106 Heredity. 



According to Darwin, Waterton gives a curious case 

 of a heii which had ceased laying, and had assumed the 

 plumage, voice, spurs and warlike disposition of the 

 cock: when opposed to an enemy she would erect her 

 hackels and show fight. 



Female deer often acquire the horns, peculiar hair, 

 ears, odor, and sexual desire of the males. 



On the other hand, it is well known that the secondary 

 sexual characteristics of male animals are more or less 

 completely lost when they are subjected to castration. 



Darwin states, on the authority of Yarrell, that if the 

 operation be performed on a young cock, he never crows 

 again; the comb, wattles and spurs do not grow to their 

 full size, and the hackels assume an intermediate appear- 

 ance between the true hackels and the feathers of the 

 hen. Similar results are said to be produced by confine- 

 ment. 



Buffon states (Hist. Nat., Tom. vi. p. 80) that the 

 horns of a stag castrated during the rutting season 

 become permanent, but that new horns do not usually 

 appear if it is castrated when out of heat. 



Simpson says (Cyc. of Anat., Vol. ii. p. 717), "From the 

 frequency with which castration is performed, the effect 

 of the testes in evolving the general sexual peculiarities 

 of the male have been more accurately ascertained than 

 that of the ovaries upon the female constitution. These 

 effects vary according to the age at which the removal 

 takes place. When an animal is castrated some time 

 before it reaches the term of puberty, the distinctive 

 characteristics of the male are in general never devel- 

 oped; and the total absence of these characters, together 

 with the softness of their tissues, the contour of their 

 form, the tone of their voice, and their want of energy 

 and vigor, assimilate them more in appearance and 



