130 



MR. L. DONCASTEtt AND REV. G, H. RAYNOR ON [Feb. 20, 



It was now shown that the recessive variety hitherto known in 

 the female only could be transferred to the male by pairing a 

 heterozygous male with a recessive female. It remained to pair 

 male and female of the variety together, and to pair the recessive 

 male with the heterozygous female. Both these paii-ings were 

 efiected in 1904 and repeated in 1905. 



Lacticolor $ X d (Table XI.) have given exclusively lacticolor 

 ofispring, male and female ; the recessive character breeds true, 

 as was expected. 



Lacticolor S X heterozygous $ (Table X.) have given all the 

 males normal, all the females lacticolor; a result which may have 

 important beaiing on the theory of the determination of sex. 



To sum np — • ■ 



DR $ X DR cJ gives DD c? , DR c? , DR 2 , RR $ . 

 R$xDRc? „ DRc?, RRc?, DR$, RR$. 



R$ XDRc? 



DR$ xRc? 

 R? xRd 



DRc? 



Rd 



RR? 



R? 



Table YIII. — Heterozygous $ x heterozygous c? 

 (Type DR x DR.) 



Table IX. — Lacticolor $ X heterozygous J . 

 (Type R § X DR c? .) 



