328 Toyama, Mendel 1 8 laws of heredity as applied to the silk-worm crosses. 



The sec (nid generation. 



The second generation mated with similars presented the 

 typical Mendelian phenomenon of the segregation of the parent 

 characters. 



Each mating of the striped yellow forms produced four diffe- 

 rent kinds of worms, 1. no-marking white or pale white, 2, no- 

 marking yellow, 3. striped white and 4. striped yellow. 



Thus 35 parents of* striped yellow forms gave: 



1. no-marking white worms .... 691 (6,1 " „). 



2. no-marking yellow worms .... 2099 ( 18, •">:'." ,,), 

 .!. striped white worms 2147 (18,96°| ), 



I. striped yellow worms 6385 (56,38 ° ). 



Each of the no-marking yellow matings also gave two kinds 

 of worms in the following proportion: 



1. no-marking white worms 252 (25,22 "/,,), 



2. no-marking yellow worms 747 (7 1,77 " „i. 



The third generation. 

 In the third generation derived from the inter se breeding, 

 each of those forms above enumerated exhibited the following 

 segregation and combinations of characters: 



1. No-marking white forms produce offspring similar to parents, 

 without any exception. 



2. Of 15 no-marking yellow parents mated with similars, 8 pro- 

 duced uniform no-marking yellow broods, while the rest 

 (7 parents) produced mixed broods consisting of no-marking 

 yellow (1507 = 76,73 °/ ) and no-marking white (457 =23,26 °/ ). 



3. Of 16 striped whites, we got the following results: 7 parents 

 produced offspring entirely similar to the parents, 9 parents 

 produced mixed offspring (striped white 1698= 77,11 °/ and 

 no-marking white 504 = 22,88 °/ ). 



4. Of 21 matings of striped yellow forms, 8 matings produced 

 the striped yellow offspring; 3 matings produced mixed offspring 

 of striped white (240=26,17%) and striped yellow (677 

 = 73,82 °/ ); 8 produced the mixed offspring of striped yellow 

 11475 = 74,2%) and no-marking yellow (513 = 25,8%); and 

 lastly two matings produced four kinds of worms, the average 

 proportion being: 



striped white 90 = 15,36 °/ , 



no-marking white 43= 7,34" ,,, 



striped yellow . .. 326= 55,72 °/ 0J 



no-marking yellow 126 = 21,53 /„. 



Posterity of these various forms. 

 By removing all other forms during four generations we have 

 sueeeeded to establish a constant striped yellow form. Hence from 



