3O8 R. M. STRONG. 



TABLE XIX. 



WHITE MALE X WHITE FEMALE. MATING 25. 

 Offspring: All white: i male, 3 white females, 3 sex ?. 



No. 5 was attempted with the ring-doves because of a lack of 

 white stock females. At the time the ring-dove matings were 

 made, the work of Durham and Marryat was not known to the 

 writer. 



In all of the parallel cases (and these include some forms 

 outside of the bird group), when the male parent has the dominant 

 character, the offspring in FI resemble the male parent and few 

 or no females occur as a rule. When in the reciprocal cross the 

 male bird is recessive, the offspring in FI are about equally males 

 and females; the recessive characters appear only in female 

 offspring. 



The sex-ratio for FI offspring bearing the dominant characters 

 varies greatly in different combinations. In both the canaries 

 and the ring-doves the number of dominant females is very small 

 and the proportion seems to be about the same in both. In 

 some other combinations, as in the case of the crossings which 

 were made by Pearl and Surface ('ioa) between Barred Plymouth 

 Rock males and Cornish Indian Game females, about equal 

 numbers of males and females had the dominant barring. No 

 females were barred in the reciprocal cross, however. 



Other essentially similar cases are given in the following table 

 where the dominant form is placed before the recessive. The 

 famous experiments with currant moths described by Doncaster 

 and Raynor ('06) could be included in this list if laticolor males 

 occurred in nature. 



TABLE XX. 



(Fi females have dominant characters only when the male 

 parent has them, in the following combinations:) 

 Crossings. 



Brown Leghorn X Silky fowl. Bateson ('09 and 'n). 



Black-red Game Bantam X Brown-red Game Bantam. Hage- 

 doorn ('09). 



White Rock X Brown Leghorn. Goodale ('10). 



White Wyandotte X Brown Leghorn. Sturtevant ('n). 



