6 GONADECTOMY IN RELATION TO THE SECONDARY 



Special attention is directed to those statements in the hterature 

 according to which the secondary sexual characters of the male bird 

 do not develop after castration. Thus, Marshall writes: 



"It is well known that caponization or the removal of the testes in fowl 

 arrests the development of the comb and spurs and other secondary male 

 characters which are normally present in the cock."^ 



As far as I can learn, the only characters for which the statement 

 holds true are the comb and wattles, the crowing instinct, and the 

 sexual reactions, and even here it appears that the last two are merely 

 suppressed but not really absent, since both are occasionally observed 

 in perfect capons. Certainly, whatever foundation there may be for 

 such statements regarding the spurs and plumage is to be found in 

 some other circumstances than castration. A further discussion of the 

 point is given below. 



It has not been easily possible to verify by experiment the inferences 

 regarding the condition of the ovary in relation to the plumage and 

 other secondary sexual characters, because its complete experimental 

 destruction or removal has involved some practical difficulties, owing 

 to its situation upon some of the main blood-vessels of the abdominal 

 cavity. On the other hand, the experimental removal of the testes 

 is accomplished with such ease that it has long been a common practice 

 among poultry growers to castrate their surplus cockerels because of 

 improved eating qualities. This result, however, may be secured with- 

 out an absolutely complete removal of the testes and epididymis; that 

 is, good capons are sometimes found with a small amount of tissue on 

 the site of the testes. 



The effects of castration on the secondary sexual characters of the 

 cock have been studied by a number of observers, who report, in general, 

 that, with the exception of head furnishings, the characters of the male 

 develop in nearly the same way as those of the normal male. It is true 

 that in some instances it has been recorded that these characters, such 

 as spurs, luster, long feathers, etc., either fail to develop or develop 

 imperfectly. However, anyone with a moderately wide acquaintance 

 with poultry can easily observe many instances of the same sort among 

 males that have not been castrated : Plumage which lacks in luster is 

 common among males of low vitality, though otherwise normal; spurs 

 develop very slowly in some races ; the males of some breeds have relatively 

 short sickle feathers, and so on. In other words, the characteristics 

 described presumably have nothing to do with the results of castration. 



True hermaphrodites may also exhibit characters of both sexes, but 

 since they have the primary organs of both sexes present they can not 

 well afford critical evidence on the points involved in this paper. The 

 possibility that these may be genetically females will be discussed in 

 the body of this paper. 



'Italics mine. 



