K. ToYAMA 397 



The further posterity of the lineages above mentioned will follow 

 exactly the same course- mentioned in the case of raatings Nos, 4 and 5 

 (see page 393). 



Thus the result of back-crossing may be summarized in the following 



scheme : 



( ? F, D X ,f iJJ2) {9 RR X i Fi D) 



I I 



Fi CRgs ... . D R 



F2 eggs ... {D + R) {D + R) 



._!_. 



I 1 I 1 



I II I 



F3 eggs ... (D + R) R (D + R) 



I 



F4 eggs D {D + R) Constant 



This expectation was realized by the results of back-crosses between 

 the Theophila-Bomhyx F^ moths and pure Bombyx ones which are quoted 



below : 



r= green-shaded eggs like those laid by Theophila-Bomhyx F^ moths. 



ir=divoltine white eggs ; iV= normal Bombyx eggs. 



/= intermediate forms between Theophila and Bombyx or mixture. 



As the figures shew the result actually obtained by experiments 

 is in perfect accordance with that demanded by the theory except for 

 the appearance of the antagonistic characteristics in the F^ of Bomhyx 

 typed or recessive series. This is due, I think, to the presence of 

 divoltine white character which prevents the elimination of the an- 

 tagonistic character in F^ eggs. 



