K. ToYAMA 397 



The further posterity of the lineages above mentioned will follow 

 exactly the same course mentioned in the case of matings Nos. 4 and 5 

 (see page 393). 



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

 scheme : 



{?F, D X i RR) {i RR X s F,D) 



I 

 Fi eggs ... D R 



I I 

 r ' -: I -L 1 



I III 



F., egg.s ... {D + R) {D + R) 



I I 



I II I 



F., egi?s ... (D + R) R {D + R) 



J_ I 



r 1 I 



F4 eggs 1) (D + K) Constant 



This expectation was realized by the I'esults of back-crosses between 

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

 below : 



r=green-shaded eggs like those laid by Theophita-Bombyx Fi moths. 



ir=divoltiue white eggs ; W=normal Bomhyx eggs. 



/= intermediate forms between TheophUa and Bomhyx or mixture. 



( ? i^] X J Bomhyx) ( ? Bomhyx x i Fi) 



I I 



F, eggs ... T N 



I 

 r ' n 



■ 1 I 



(T + K + I) 



I 

 W 



I 1 



I I 



(T + iV + /) 



I 

 W 



I 



N 



I 

 N 



I 

 Constant 



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 i'l, 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. 



