No. 614] 



THE BLUE ANDALUSIAN 



101 



testicular secretion or the absence of ovarian secretion. 

 The black feathers from both sections show rod-shaped 

 granules predominating. There are numerous elliptical 

 granules and a few round granules present. The pig- 

 ment is not restricted as to distribution in the feather 

 structure and is found even in the tiny hooklets of the 

 hooked barbules, being in all these respects similar to the 

 analogous feathers on a black male. These same condi- 

 tions prevail in homologous pigmented feathers in a blue- 

 splashed male. 



The foregoing describes the conditions that usually 

 prevail. There is some variation in all conditions de- 

 scribed. In pure-bred blue Andalusians, for instance, 

 there frequently appear areas that are not the usual clear 

 blue-gray, but are dull and smoky. In such regions both 

 round and rod-shaped granules are found in about equal 

 numbers. 



Bateson and Punnett (1906, p. 20) make note of the fact 

 that the adult color of Andalusians may be determined 

 from the down color of the young chicks. Examinations 

 of the down show the same differences in granule shape 

 that are observed in the adults. The blue and blue- 

 splashed chicks for the most part show nothing but round 

 granules in the down, while the blacks show rods. 



It is of interest to note in this connection that a section 

 from that portion of a barred Plymouth Rock feather 

 where the black bar is giving way to the white, and the 

 color is dull gray or dun with no bluish cast, there is a 

 dilution of pigment as to amount, but no restriction as to 

 arrangement or distribution. The pigment is fully ex- 

 tended through the barbule cells and consists of rod- 

 shaped granules. There simply appears to be less pig- 

 ment. While this is the usual condition, here, too, there 

 is variation. At least one barred Rock individual was 

 found whose feathers showed numerous round granules, 

 though the rods predominated. 



While it is generally accepted that blue Andalusians, 

 when mated inter se, produce blacks, blues and blue- 

 splashed in the ratio of 1 black to 2 blues to 1 blue- 



