ON SOMATIC SEX-CHARACTERS 85 



in September without any renewed activity of the 

 testis and long before the beginning of spermato- 

 genesis. The case of the antlers in the stag is 

 probably very similar. 



The important statement is made with regard to 

 castration (under anaesthetics, of course) that it was 

 found impossible to extirpate the testes completely. 

 When the bird was killed some months after the 

 operation, a greater or lesser amount of regenerated 

 testicular tissue was found either on the original site 

 of the organs or engrafted upon neighbouring organs. 

 This experience, it will be noted, agrees with my 

 own in the case of fowls. There were, however, 

 reasons for believing that the results observed 

 within the first six or eight months after the opera- 

 tion are not much different from those which would 

 follow complete castration. 



Castration carried out when the drake was in 

 nuptial plumage produced the same effect which 

 was observed by Goodale, namely, delay, and im- 

 perfection in the assumption of the eclipse condition, 

 but the observations of Seligmann and Shattock are 

 more precise and detailed. One example described 

 was castrated in full winter plumage in December 

 1906. On July 11, when normally it would have 

 been in eclipse, the nuptial plumage was unmodified 

 except for a diffuse light-brown coloration on the 

 abdomen, which is stated to be due not to any growth 

 of new feathers but to pigmentary modification in 

 the old. By September 1 this bird was almost in 

 eclipse but not quite ; curl feathers in the tail had 

 disappeared, the breast was almost in full eclipse, 

 the white ring was slightly indicated at the sides of 

 the neck, the top of the head and the nape had still a 



