The Mendelian Inheritancr of Certain Chemical Characters in Maize. 15 



most markedly differentiate the two parent races crossed. That the 

 sugar content (inchiding both sucrose and dextrose) segregates in F., 

 in a MendeUan fashion is evident. This is particularly striking in 

 the case of dextrose. The dominance in respect to this character is 

 not perfect in Fj. Measureable amounts of dextrose are found in the Fj 

 kernels, although these are typical dent (starchy) kernels in appearance. 

 In F2, however, there is no measureable amount of dextrose in the 

 starchy kernels. 



The most striking result in Fa with reference to the sugars is the 

 intensification of the recessive character (high sugar content). 

 The total sugar content of the Fo sweet kernels is nearly as great as 

 that of the original parent sweet maize, which is itself well above 

 the average of sweet corns in respect to sugar content. This increase 

 in sugar in the Fo sweet segregates appears in both sucrose and 

 dextrose but is relatively greater in the latter. The relatively great 

 amount by which the sugar content is increased in these F., segregates 

 is indicated by the fact that Straughn (loc. cit. Table V, p. 44) in 

 an analysis of 62 separate samples of Stowell's Evergreen corn with 

 an average total sugar content in the dried seed of 4.04 per cent, 

 finds only 5.44 per cent as the maximum total sugar content in the 

 62 samples. Our Fo segregates average 7.865 per cent (8.56 per cent 

 water free) total sugars in the completely matured and dried 

 seed. It is evident that an extraordinary increase in the total sugar 

 content has been associated here with the processes of gametic mixture 

 and subsequent segregation. 



The explanation of this intensification of characters accompanying 

 segregation is not clear. The present case is by no means an isolated 

 one, however. Attention has recently been called (10) to a similar 

 phenomenon in the segregation of the barred color pattern and comb 

 types in fowls. A more perfect or "intensified" condition of the 

 characters appears in the F^ segregates than existed in the parent 

 forms. Results of this kind may be due to purely gametic causes 

 (germ variation, gametic "purification" in gametogenesis following a 

 wide cross etc.) or to purely ontogenetic causes (for example more 

 perfect activation of determiners following crossing), or to a com- 

 bination of these causes. The observational basis respecting the 

 phenomenon is as yet much too slender to permit the rearing of any 

 speculative superstructure upon it. It may further be said that we 

 are quite possibly dealing here with an extreme aspect of a pheno- 

 menon which has long been held by practical agriculturists to occur: 



