28 INHERITANCE IN POULTRY. 



MATERIAL,. 



As mothers, Nos. 8 and 1 1 (page 21), original Houdan stock, and later their 

 daughters, Nos. 60 and 81, were used. No trap nests were employed in 

 this series and consequently mothers are not exactly known. 



Father: No. 27, bred at the station, August, 1904, son of No. 12, 

 Minorca cock (page 6) and a Minorca hen. 



RESULTS. 



1 . GENERAL PLUMAGE COLOR. The young hybrids, like the young black 

 Minorcas, contain much white on the belly and primaries. In later molt- 

 ings the white is replaced by black, but even at five months the primaries 

 are sometimes mealy or white-spangled. Except for this the hybrids have 

 lost the Houdan white and are of the Minorca color. Minorca uniform 

 black is dominant over the Houdan mottling. 



2. COMB. First hybrid generation. Of 20 offspring 18 have a Y-shaped comb 

 like the hybrids of Polish and Minorcas. In two cases (of egg embryos) the 

 comb was recorded as single, but this is probably only the limiting condi- 

 tion of the Y-shaped comb, which is here also the heterozygous form. 



3. NOSTRIL FORM. First hybrid generation. In no case does the nostril 

 width exceed one-half. As in Series I and II, there is imperfect dominance 

 of the narrow form. However, the nostril in this cross runs lower than in 

 the Leghorn X Houdan cross. 



4. CREST. This is present in all first hybrids reared to a sufficient age to 

 render an opinion possible. 



5. CEREBRAL HERNIA. Fj. Always absent. One egg embryo, which died 

 at about 17 days of incubation, had a vesicle protruding, uncovered by 

 skin, from the top of the head at the usual position of the hernia. Such a 

 teretological case is not uncommon in straight- bred Houdans. It is note- 

 worthy to find it here where the cerebral hernia is recessive. 



6. 7. MUFF AND BEARD. f^ Present in all older hybrids. 



8. FOOT COLOR. Fj. Always black as in the Minorca. 



9. TOES. Of 21 hybrids, 12 have 5-5 toes, 3 have 5-4 toes, and 6 have 4-4 

 toes. The proportion without extra toes is higher than in the Leghorn x 

 Houdan first cross, being there 16.2 per cent, here 28.6 per cent. 



CONCLUSIONS. 



The following characteristics apparently exhibit alternative inheritance: 

 Plumage color, nostril form, crest, cerebral hernia, muff and beard, leg 

 color, and number of toes. Dominant are: Uniform black plumage color 

 (imperfect), narrow nostril (imperfect), crest (imperfect), cerebral hernia 

 (imperfect), muff and beard (imperfect), and black leg color. Of these the 

 crest, muffling, and black leg color are positive characters in de Vries' sense 

 and are dominant. The color pattern of the Houdan yields here to black 



