42 GONADECTOMY IN RELATION TO THE SECONDARY 



misleading. Nevertheless, some general statements may be made. 

 While the Brown Leghorn capons are obviously somewhat larger than 

 the normal male, such a condition is not so obvious in any of the cas- 

 trated drakes, although the weights indicate some increase in size. 



The castrated ducks approximate the size of the normal female. 

 The castrated pullets, too, remain about the same size as normal pul- 

 lets, although they seem relatively small. The apparent lack of size 

 is due to the fact that the legs remain small, like those of the hen, while 

 the plumage develops like that of the cock, thus producing a small- 

 bodied, short-legged bird quite different from the cock or capon with 

 large frame. All that can be said of the size relations at present is 

 that the body-size of the castrated pullet does not exceed that of her 

 normal sister. The shanks, likewise, though spurred, are of the same 

 size as those of the normal female. 



EFFECT ON BEHAVIOR. 



Completely castrated individuals of all kinds are on the whole nega- 

 tive in behavior as compared with normal adults. The behavior of 

 castrates corresponds rather closely to that of young birds shortly 

 before they become mature. The birds eat, drink, and move about 

 rather quietly. The capons do not ordinarily crow or pay any particu- 

 lar attention to the hen. They are not pugnacious, and if attacked will 

 not often fight. The poullards never visit the nests, never "sing" or 

 cackle, show none of the normal female sexual reactions, and few or 

 none of the male's. The castrated ducks are neither more nor less noisy 

 than their mates, but sexual behavior is wanting. Normal drakes 

 sometimes attempt to tread castrated females (Type I as well as Type 

 II) that are kept in the same pen. The duck, however, attempts to 

 escape, so that the male gets little satisfaction. Evidently the color 

 loses any value it may have had as a recognition mark. On the other 

 hand, castrated females introduced into a strange pen have been 

 treated at first as a strange male. It is clear, too, from the behavior 

 of hens when a poullard is introduced into a pen which contains no 

 male that they regard the poullard as a male. The poullard, however, 

 does not behave as a male, but is rather indifferent, though in one test 

 the bird was extremely pugnacious and attacked every hen that 

 approached. 



EFFECT ON ACCESSORY ORGANS OF REPRODUCTION. 



Most of the birds operated on are still alive, so that general state- 

 ments only can be made regarding these organs. Usually the vas 

 deferens in both castrated drakes and capons can not be found unless 

 there has been a considerable regeneration of spermatogenic tissue; but 

 occasionally it remains visible as a thin strand of tissue with few or no 

 convolutions. The papilla? of the capon also have not been found, but 

 as these are very small in the cock, such a result is not surprising. In 



