164 Bulletin No. 155.— 1913. 



Black Minorcas, Black Javas, Black Cochins, and Black Langshans, 

 although the Black Spanish breed has probably been kept fairly 

 pure. In no case, however, is it positive^ knowTi that barred stock 

 has entered into the formation of these breeds. It was therefore at 

 first assumed that the appearance of barring in the progeny from these 

 birds would indicate that this pattern had been formed de novo as a 

 heterozygous condition, or that it w^as inlierited from the white stock 

 in which it existed as a cryptomere as in the case of the White PI3'- 

 mouth Rock breed. Whether this was a justifiable assumption will 

 appear in the course of the experiments now to be described.* 



Case 1. — White Leghorn c^ X Black Hamburg 9- Nature of 

 mating: CCBBffll X CCbbFfii. (For discussion, see p. 186). 



White Leghorn cf 193A: Weight 53 2 ibs., back of medium 

 length; squirrel tail; body medium length, high on legs; high 

 comb with six points, slightly thumb-marked and blade defi- 

 cient in size; head long, eyes red; ear-lobes white but spotted 

 with red; wattles of medium size with one fold in each; neck 

 white with tendency to cream; back white; shanks, toes and 

 beak pale yellow; spurs about one inch in length; no pattern 

 observable on any of the feathers, which are also free from 

 black ticking. (See PI. I). 



Black Hajnburg 9 , 1S5A'\: Weight 4^ lbs., neck of good 

 length; back long; tail carried high; body long but not deep; 

 comb of good size, rather flat on top, spike with marked u])-turn 

 at rear; eyes dark hazel; ear-lobes bluish white and about 

 half red; wattles very small, fine texture, smooth. Feathers 

 of neck greenish black with purple barring; primaries dull 

 black, secondaries and main tail feathers greenish black with 

 some purple barring; bodj- dull black; shanks dark slate; spurs 

 about J inch long. (See PI. III). 



The data on the first set of W. L. X B. H. matings are summarized 

 in the following table : 



*It will be convenient to include in the present section only the actual experimental results. All 

 discussion of the significance of these result.s, together with their explanation, is taken up in Section 

 IV, p. 182. 



tBlack Hamburg 186A resembled 185A in nearly all points. 



