256 



Toyama. 



yellow etc. differs greatly from that of the yellow-blooded, hence 

 I shall discuss them separately. 



We may enumerate many other recessive whites studied by 

 Coutagne ('02), Kellogg ('08), Ishiwata ('08) the writer ('06) and 

 recently by Quajat ('11) which are tabulated below: — 



Fl 



names of ex- 

 perimenters. 



Coutagne 

 Kellogg 



Ishiwata 



Ishiwata 



and the writer 



The writer 



Quajat 



1. "Jaune Var" x "Changhai Blanc" .... 



2. Italian yellow x Chinese white 



3. ,, ,, X Japanese white 



4. Istrian yellow X Chinese white 



5. ,, ., X Japanese white 



6. Persian yellow x Chinese white 



7. Korean yellow x Japanese white 



8. Chinese yellow x ,, ,, 



9. Japanese green x ,, ,, 



10. Siamese yellow x Siamese white 



11. ,, .. X Japanese white 



12. Italian yellow (Aburuzzo) X Japanese white 

 13- ■■ .■ (Pergia) X „ „ . 



14. .. .. (Ascoli) X ,. ,, . 



15. European yellow x Chinese white .... 



Now it becomes quite clear that in silk-worms there are many 

 Mendelian whites which always behaved as hypostatic towards 

 yellows (both European and Japanese). 



We shall next see how European whites behave in inheritance 

 towards Japanese yellows or whites. The whites used for our ex- 

 periments are Italian white and "5?«^ Blanc'\ both of which, when 

 paired inter si', gave the following offspring (see Table II): 



As the figures show, they did not breed true to parents, some 

 giving all white broods, and the rest mixed broods, the proportion 

 of white and yellow being nearly 3 w : i Y. We may, therefore, 

 suggest that the whites are not homozygous in their zygotic con- 

 stitution, some of them are heterozygous with yellow. 



Now then, let us see the behaviour of European whites and 

 yellows towards Japanese white and yellows. 



