14 THE GENETIC AND THE OPERATIVE EVIDENCE 



ing like those of the epididymis and also a few testicular tubules. 

 At the old situs there were some regenerated lumps, which in sections 

 appeared to be loose glandular tissue. No germ-cells were present and 

 the tissue just referred to may be old testicular tubules. 



HEWITT'S SEBRIGHT HEN THAT BECAME COCK-FEATHERED 



IN OLD AGE. 



Darwin records in Chapter XIII of Animals and Plants under 

 Domestication a change that took place in an old female Sebright : 



"Mr. Hewitt possessed an excellent Sebright gold-lace bantam hen, which, 

 as she became old, grew diseased in her ovaria and assumed male characters. 

 In this breed the males resemble the females in all respects except in their 

 combs, wattles, spurs, and instincts; hence it might have been expected that 

 the diseased hen would have assumed only those masculine characters which 

 are proper to the breed, but she acquired, in addition, well-arched tail sickle- 

 feathers quite a foot in length, saddle-feathers on the loins, and hackles on the 

 neck — ornaments which, as Mr. Hewitt remarks, would be held to be abomi- 

 nable in this breed." 



This is the only record I know of showing the change that takes 

 place in the Sebright hen when the influence of her ovary is removed. 

 There can be no doubt from the above description that she changes in 

 the same way as does the castrated Sebright male. 



Concerning the origin of the Sebright bantam Darwin states that 

 the race "originated about the year 1800 from a cross between a com- 

 mon bantam and a Polish fowl, recrossed by a hen- tailed bantam, and 

 carefully selected; hence there can hardly be a doubt that the sickle 

 feathers and hackles which appeared in the old hen were derived from 

 the Polish fowl or common bantam; and we thus see that not only 

 certain masculine characters proper to the Sebright bantam, but other 

 masculine characters derived from the first progenitors of the breed, 

 removed by a period of about 60 years, were lying latent in this hen 

 bird ready to be evolved as soon as her ovaria became diseased." 

 To-day the problem appears to us in a somewhat different light, since 

 the secondary sexual characters referred to by Darwin have simply 

 been kept under for more than a hundred years by the secretion pro- 

 duced in the ovary of the hen (as in all breeds) and in the testis of the 

 male Sebright. 



HEREDITY OF HEN-FEATHERING. 



In 1913 I found that hen-feathering as seen in the Sebright is a 

 dominant non-sex-linked character. A preliminary statement was 

 given in the first edition of my book on Heredity and Sex (1913), 

 which treated the character as a recessive one. This was a mistake 

 due to a male having been obtained that was like the game race, 

 which subsequent work showed must have been due to a sperm hav- 



