No, 635] 



"PELVIC WING" IN POULTRY 



537 



American and Mediterranean breeds at three weeks of 

 age or younger and on English and Asiatic chicks a week 

 or two later. 



In the routine of describing three-weeks old chicks in 

 connection with certain genetic studies, the writer has 

 noted and recorded the presence of this structure on sev- 

 eral hundred individuals. It has seldom been lacking on 

 chicks of the Mediterranean breeds and crosses, and is 

 usually found on chicks of the American breeds, and fre- 

 quently on those of English and Asiatic breeds of this 

 age. Its non-appearance in chicks of the lighter breeds, 

 by the time they are three weeks old, is usually asso- 

 ciated with low vitality and general slowness of feather- 

 ing. The heavier breeds are naturally slower in passing 

 from the down to the feather stage and its failure to de- 

 velop in the first three weeks is more frequent. 



While not all of the individuals which failed to show 

 the so-called pelvic wing in three weeks were reexamined, 

 many of them were and in every instance the structure 

 was found at some stage of development. The parents 

 of the chicks observed were not only of several distinct 

 breeds and classes but were frequently from widely sep- 

 arated sections of the country. The number of observa- 

 tions made and the various sources of the breeding stock 

 seem to warrant the belief that the " pelvic wing" in the 

 young domestic fowl is of fairly constant occurrence. 



It is interesting to note in this connection that the 



