Primary Genetic Possibilities 429 



discuss a proposal of a balance between trigger and promoter genes, 

 which, I think, is based upon a misunderstanding of the facts). 

 We come to the conclusion that the "naive" theory which requires the 

 unspecific trigger in the sex chromosomes can be absolutely excluded 

 in Lymantria, and therefore in other animals and plants which follow 

 the same scheme. Apart from the basic experiments on production of 

 intersexes in an orderly way after appropriate crosses, which require 

 the simple balance theory, three more sets of tests exclude any but the 

 balance interpretation and establish the fact that normal sexes as well 

 as all types of intersexuality are exclusively the result of the balances 

 and imbalances between female determiners in the Y-chromosome 

 (in Lymantria!) and male ones in the X-chromosomes (not using the 

 W-Z designation in this case of female heterogamety ) , This, of course, 

 does not exclude modification by genetic or environmental action. 



The first set of experiments consists of multiple crosses. For 

 example, in the races A B C ( etc, ) female and male determiners have 

 different strengths or potencies (whatever this means in detail; see 

 III 5 C tt), as evidenced by the results of crosses in regard to produc- 

 tion of normal ofi^spring or any definite grade of female or male inter- 

 sexuality, including both kinds of sex reversal. We might now cross 

 A X B, and the hybrid from this cross to C, that is, (A X B) X C 

 (mothers given first). In this way we might finally come, for example, 

 to the following cross: 9 ( ( (A X B) X C) X ( (D X E) X (F X G) ) 

 XN))) crossed with 5 ( ( (B X D) X (F X G) ) X N) ) ) X N, In 

 such crosses all kinds of autosomes are brought together, and the most 

 varied combinations are expected. If "sex-promoting" genes in the 

 autosomes were responsible for the effect, unpredictable results would 

 follow. Actually, at every step of such a buildup and also in the end, 

 and this in the most varied combinations of races of known potencies, 

 the result is exactly the same as if a female of race A ( in the example ) , 

 which supplied the Y-chromosome for all further combinations in- 

 cluding the last, and a male with one X-chromosome from the mother, 

 that is, N, and another one from the father, which in the example can 

 only be N, were crossed. In the example the result is the same as 

 A X N, without any influence of B, C, and so on. Thus no explanation 

 of this result other than by the balance of F(Y)/M(X) or F(Y)/ 

 M(X)M(X) is possible. 



The second example, which leads to the same conclusion, is the 

 so-called Hokkaido replacement series, also briefly mentioned above 

 (details in 1930). The basis of this experiment (fig. 23) is that if a 

 Y-chromosome = F from a very strong race (e,g,, Tokyo) is combined 



