JO Pearl and Bartlett. 



there is a definite tendency towards the complete dominance of the 

 chemical conditions found in the dent parent over those found in the 

 sweet parent. This dominance is by no means perfect in all characters, 

 however. In particular the F^ kernels are plainly intermediate between 

 the two parents in respect to sugar content, both of reducing and 

 cane sugars. In respect to ash, crude fiber, and pentosans the Fi 

 kernels run distinctly below either parent. In geireral it appears that 

 with respect to these chemical characters of maize, as in so many 

 other cases, the Fj heterozygotes are distinguishable from the parent 

 bearing the dominant character. The Fj kernels in these experiments 

 are not to be told by visual examination from the pure dent parent, 

 yet a chemical analysis shows that they really are different, lying 

 close to this parent, it is true, but still in a definite degree inter- 

 mediate in character between the two parents. 



This result in Fj is of interest in connection with the statement 

 made by Webber (12) to the effect that (loc. cit. p. 32): "In the 

 writer's experiments, however, particularly in the case of dent races 

 with starchy endosperm crossed with sugary races with sugary endo- 

 sperm, there has been no indication of a modification of the chemical 

 constitution." Careful examination of Webber's paper fails to discover 

 that this statement was based on any exact anal5d;ical data. Rather it 

 was apparently based simply on the external appearance of the grains, 

 which is, as has been said, like that of the pure dent parent when the 

 sweet corn is the ä parent. The present results show clearly enough 

 that the F^ (heterozygote) endosperm is distinctly different in chemical 

 composition from either of the pure parent forms, containing, for 

 example, more than a fifth more sugar than the pure dent parent. 



We may turn next to the 



Fo Generation. 



At the outstart attention should once more be directed to the 

 fact that all of the kernels whose analysis is headed "Fg Progeny" 

 in Tables I and II came from the same ears. That is to say the 

 yellow starchy kernels, the white starchy kernels, the yellow sweet 

 kernels and the white sweet kernels in the Fg generation all grew 

 upon the same plants and upon the same ears. Therefore, the 

 environmental conditions under which they obtained their development 

 were as nearly identical as it is possible to get. Such differences 

 between these kernels as appear in the analyses cannot be accounted 



