196 Heredity and Eugenics 



obtained from Generation III at the end of August, 1909, 

 gave the following results: 



A B c D E 



o 5 362 8 o 



I then mated at random for the parents of Generation 

 IV, one male of B, the only one that could be found alive, 

 three males and three females of C, two males and two 

 females of D, and none of E, they being absent. This 

 material bred at once and gave in the fourth generation a 

 considerable progeny, which were all of the dominant type. 



Material from Generation IV, brought to Chicago in 

 August, 1909, placed in hibernation under experimental 

 conditions, and brought out to breed in the middle of the 

 winter, has shown that the dominant type is a fixed type, 

 and that it breeds true and does not split in subsequent 

 generations. The only splitting is that which occurs in rare 

 individuals in from 2 to 3 per cent of the progeny, which 

 stand apart from the general population as sports. These 

 cases are practically the reappearance of one or the other of 

 the component characters or combinations thereof that went 

 into the cross, and they do not represent in this experiment 

 anything in the way of characters new to the genus or family 

 as DeVries states to be true of his mutants, rather they 

 are simply the characters obtained from the different parents 

 from which this complex has been built up. 



The same combination of material was made in Chicago 

 in 1908, and was run through essentially the same pro- 

 cedure as that of the Tucson experiment, with this difference 

 in the result, that at Chicago L. decemlineata completely 

 dominated the culture to the total exclusion, as far as analy- 

 sis has been able to discover, of the presence of the other 

 parents. 



