26o 



D. F. JONES. 



cient maturity to permit classification. In plants many cases 

 are known in which there is a selective elimination of certain 

 classes of individuals due to a lesser germination and unequal 

 ability to grow. In Drosophila (Hyde, 1914) crossing does not 

 influence the number of eggs laid but markedly regulates the 

 per cent, that hatch. Therefore the error from this source 

 always tends to show an apparent deviation in favor of cross- 

 fertilization. In maize where the seed progenies can be used this 

 differentiating effect is at a minimum and probably is not suffi- 

 cient to affect the numbers appreciably but since the tendency is 

 in the opposite direction to the results which have been obtained 

 the data are even more convincing. 



TABLE I. 



CHARACTERS OF THE SEEDS AND PEDIGREE NUMBERS OF THE INBRED STRAINS AND FIRST 



HYBRIDS USED IN THE MIXED POLLINATIONS. 



GENERATION 



