or practical breeders discovered this work or noted its significance. Others 

 were also carrying on experiments, however. By the end of the century three 

 botanists, working independently and each one experimenting with different 

 material, were arriving at the same conclusions Mendel had reached. They 

 discovered Mendel's old report and called attention to it. These three bot- 

 anists were the Hollander Hugo de Vries, the Austrian Erich Tschermack, and 

 the German Karl Correns. 



While these investigations were going on, an American breeder was making 

 the same discoveries in an effort to develop a wheat especially suitable for 

 growing in the Northwest. In the region about Pullman, Washington, the 

 farmers had for years tried out many varieties of wheat in order to decide 

 which was the most profitable to grow. They found only the Little Club 

 variety at all satisfactory. The straw was strong enough to withstand the 

 summer storms, and the head remained closed after the grain was ripe, thus 

 preventing loss before harvesting. But when Little Club was planted in the 



BERNAUD 

 I- Ri CD MAN 



,- .^ 



.y 



i.^' 



White-long- 

 smooth (1) 



Black-long- 

 smooth <3) 



White - long - rough [3] 



Black - short -smooth [9] 



' \ 



,^' 



White- short- 

 rough (9) 



White-short- 

 smooth (3) 



INDEPENDENT ASSORTMENT OF CHARACTERS 



Black-short- 

 rough (27) 



Black- long - 

 rough (9) 



AfHT exi)erimeius by W, K. Castle 



In guinea-pigs pigmentation is dominant, as are shortness of hair and roughness of 

 coat. When two pure-bred individuals like Pi and P2 are mated, all the hybrids will 

 be dark, short-haired, and rough-coated, like Fi. If such hybrids are now mated in 

 sufficient numbers, the next generation will yield every possible combination of the 

 three sets of characters, including the "pure" grandparent types, in the proportions 

 indicated by the numbers in brackets. And for each pair of characters there will be 

 three dominants to one recessive 



479 



