Ill II, 



Toyama, On certain characteristics of the Silk-worm etc. 



the dominant lineage will be D and (D -j- R), that is to say, certain 

 lineages will gave all D F 4 eggs, while others will give both D 

 and R batches in certain proportions. 



In the F 3 R series, those derived from the mating No. 7 in 

 the above formulae will produce all F 4 D eggs, those from mating 

 No. 8 a mixture of D and R batches, and lastly, those from mating 

 No. 9 will give all R batches in F 4 . Thus the F 4 of the R series 

 will be D, (D -f- R), and RR, or some matings giving all D batches 

 in F 4 , some a mixture of D and R batches while the others are 

 all R eggs. 



If we eliminate the lineage which produced the antagonistic 

 characteristics in both D and R series and keep only those which 

 gave all uniform batches, the result would be: 



In the D series, we may eliminate the lineage No. 3 which 

 produced R batches in F 5 and in F 6 we may again take away the 

 lineages Nos. 2 and 4 which will produce R batches. And thus 

 we are able to establish a constant dominant form in F 7 . 



In the R series, if we keep the lineage which gave all R batches 

 in F 4 , it will be extracted as a constant R form, since, as we see 

 from the formula before mentioned, it is RR in its composition. 



The order of inheritance above described may graphically be 

 summarized as below: 



1. 



2. 



eggs 



F, 



D (outward appearance) 

 dominant female F 



D 



R (outward appearance) 

 recessive female F, 



D 



(D + 



F 4 D (D + R) 



D (D -f- R) 



F D (D + R) 



D (D + R) R 



R 



R 



R, 



F 7 D (all D) 



Let us now compare the results obtained by calculation accord- 

 ing to Mendelian principles, with those actually obtained by us. 



In the first series of line breedings before mentioned, if we 

 considered the brown batch to be the F t eggs of the female brown 

 series, the results are nearly the same, with a few irregularities 

 possibly caused by the appearance of the divoltine white, which 



