Modification of Germinal Constitution of Organisms 193 



This was especially true of the adult characters. The 

 larval characters, however, were also variable and appeared 

 to be less blended into a homogeneous group. 



The culture hibernated from early September, 1906, 

 to June, 1907. During this period a very great mortality 

 occurred, which was due very largely, I think, to the fact 

 that the culture would probably have reproduced a third 

 time in 1906 if it had been supplied with food and proper 

 conditions. 



These individuals in 1907 reproduced and gave a pretty 

 uniform progeny of the blended type between L. decemli- 

 neata and L. oblongata, Generation III: 



ABC 



2 476 o 



A fourth generation was obtained hi late August and early 

 September of the same year, which possessed the same 

 attributes as the third generation. In nature, this culture 

 was not carried beyond that stage, but material from the cul- 

 ture was brought to Chicago and carried through the winters 

 of 1907 and 1908, and the summer of 1908 and part of 1909. 

 It was subjected to various analytical experiments, all of 

 which tended to show that the type was a relatively stable 

 one. Individual pairs, when inbred, gave a very definite 

 pure line culture and groups mated at random gave the 

 same result; but, as in the colony in the Balsas River, there 

 appeared sporadic individuals, widely separated from the 

 parent stock, which, when inbred, behaved in every way 

 like DeVries' mutants. 



A culture of the same material was placed at the Desert 

 Botanical Laboratory of the Carnegie Institution in the 

 desert of southern Arizona at Tucson, near the foot of 

 Tumamoc Hill. In this experiment two males and two 



