68 JOUK-NAT. OF THE 1)eI'AHTMK> i Ol- A(.KJ( UJ.l I K h. 1 UJA', 1922. 



disappeared and been replaced by feathers in all modern birds, but 

 relics of the scales frequently persist on the leg's and toes of birds. 

 It would tlierefore be reasonable to expect that these surviviiig scales 

 niig'ht in some instances indicate hoAv the passage from scale to 

 feather has been made. As a matter of fact, we find many birds 

 Math feathers as well as scales on their legs and toes, and these should 

 provide the clue. Feathered legs are known in many breeds of 

 poultry, such as Cochins, Brahmas, Langshans, Bantams, Silkies, 

 and Sultans, while they sometimes appear in Leghorns, Minorcas, 

 Wyandottes, and Orpingtons. They also occur on the legs of domesti- 

 cated pigeons, owls, and niany other birds. Although some study 



Fui. 1. — Part of skin froiu foreleg of ostrich chick, about the time of hatching. 

 The skin is here covered with small fl<it, polygonal scales, and from the lower 

 border of each arises a short upgrowth or papilla, each of which represents an 

 early stage in the development of a feather. 



has been given to these cases of feathered legs, the actual relation- 

 ship of scale and feather has iiever been established. It will now 

 be shown that certain conditions prevailing in ostrich chicks at 

 about the time of hatching aiford the true key to the problem. 



The ostrich, as is well known, has a row of large, overlapping 

 scales passing down the front of the tarsus or shank of the leg, and 

 also over the two toes. In addition, the general surface of the tarsus 

 at the sides and behind is covered Avith very small scales, which are 

 continued for some distance up the leg, and cease where the leg- 

 feathers begin. .4/ the place of transition, where the scales, as it 

 were, are about to pass over into the naked part of the skin, they 



