33Q 



OSCAR RIDDLE. 



hackles of a sub-variety of the game-cock in which "the tips 

 having a metallic lustre are separated from the lower part of the 

 feather by a symmetrically shaped, ' transparent zone ' composed 

 of the naked portions of the barbs." In another work 1 he 

 describes the "transparent zone" of the ocellus of the peacock's 



d— - 



a - 



Fig. i. Feather from a poorly nourished chick showing abnormalities, a, abnor- 

 mal area; b, "fundamental bar" (a day's growth); c, constrictions; tl, region in 

 which defective lines showed plainly in this feather. X 2 - 



feather. Both of these belong to the sort of structure now under 

 consideration. 



Since so little has been said of these defects, and since their 

 significance has nowhere been recognized, it seems advisable to 

 give a very complete and detailed description of them. Such a 



1 Darwin, Charles, " The Descent of Man," 1871. 



