94 



POULTRY PRODUCTION 



saddle featliers or long tails with sickle feathers. Their 

 plumage is so closely similar to that of the female that they 

 are referred to as hen feathered males. Morgan has shown 

 that if Sebright males are castrated, they grow tlie long 

 hackle, saddle and tail feathers which are typical of capons 

 of breeds in which the male is not lien feathered. Boring 

 and Morgan' luu'e shown that the testes of Sebriglit males 

 carry lutear cells which are identical with those found in the 

 corjius luteum ol' the ovary of the hen by Boring and Pearl. 

 It appears probable that the agent of sui)pression is a secre- 

 tion from these lutear cells. 



Fia. 33 



^ __ -•'•is--' 



'"-'li^MSf 



Showing how bacillnry while diarrheaperpetuatositself in the broedingstock. 



Inheritance of Disease.— While the statement that infectious 

 poultry diseases are heritable is technically incorrect, practi- 

 cally it has a substantial basis in fact. The most conspicuous 

 example is found in the life history of the organism causing 

 contagious white diarrhea. When a female chick is infected 

 with the disease and makes a recovery it becomes a bacillus 

 carrier. According to Rettger, Kirkpatrick, and Jones,- 



' .Journal of General Physiolo 

 - Storr's Bulletin No, 77. 



'.y, vol. i, No. 1. 



