The (Jrigin of Featheks fhom the Scales of Reptiles . 69 



actually begin to give rise to feathers: ive have, in fact, feathers 

 grov)ing directly out of the scales. 



Tlie scale feathers are to be found on ostricli chicks only about 

 the time of hatching, and for a week or two prior to hatching. After 

 the chick leaves the egg the larger ones open out, and are exactly 

 like the down, which covers the body generally; but the greater 

 number fail to expand, and the feather germ atrophies within a week 

 or two after hatching, when the expanded feathers also fall out. 

 To see them, therefore, the ostrich farmer must examine the upper 

 part of the leg of the chick as soon as hatched or, still better, make 

 observations on any late chicks which happen to die in the shell. It 



Fig. 2. — Part of skin a little higher up the leg than that shown in fig. 1. The 

 scales, each with a feather papilla, are present in the lower part, but disappear 

 above, where the skin is naked, apart from the presence of feather filaments. 

 These latter are short and irregularly arranged at first, but above they pass 

 into the long filaments which give rise to the down covering the upper part of 

 the leg of the ostrich chick. 



will l)e found that they show much clearer in some chicks than in 

 others. 



The appearance under a low power of the microscope of a portion 

 of the skin, just before the scales leave ofl", is represented in Fig. 1. 

 Each separate area represents one of the small leg scales, which joui 

 one another by their edges. From the lower border of each a blunt 

 upgrowth or papilla emerges, which partly overlaps the scale below 

 it. Microscopic sections have been made of these upgrowths, and 



