EFFECTS OF LIGATING TESTES OF HEN-FEATHERED COCKS. 25! 



The first bird was a pure Sebright male more than a year old. 

 It was a typical bird of its race, i.e., it was completely hen-feath- 

 ered. This bird had been used in an experiment a month earlier 

 to induce beri-beri, but had fully recovered. I had seen a state- 

 ment in Science that young chicks are peculiarly susceptible to a 

 lack of vitamines in their food and that beri-beri can be induced 



FIG. 6. Hen-feathered, back-cross, rose comb, No. 270, June, 1919. 



by a diet free from or low in vitamines. The possibility that the 

 testes might also be affected by such a diet, and cause a change 

 in a hen-feathered male of the same kind as that brought about 

 by castration suggested the experiment. Two hen-feathered 

 cocks were used. Both were fed on white rice for five weeks. 

 No changes were observed to take place in their combs. Sud- 

 denly the effect of the diet became apparent, and in the course of 



