ie CIRCULAR NO. 120, BUREAU OF PLANT INDUSTRY. 
in the first or Xenia generation and to segregate as a monohybrid in 
the following generation. Since both sweet and waxy endosperms 
are recessive to horny, it became of interest to know what a hybrid 
between sweet. and waxy would produce. Six such crosses were 
made in the season of 1911. In every instance the resulting ears 
were all horny, the endosperm in every way resembling the horny 
endosperm of ordinary varieties. 
This synthetic production of horny endosperm from nonhorny 
varieties at once suggests the idea that both sweet and waxy endo- 
4 HORNY 
C HORN, 
C2 OWELT 
-~ ee 
(3 HORNY 
TOTAL J SWEET 
3 WAKY 
1? 
Fic, 1.—Diagram showing the gametie composition of second-generation hybrids between 
waxy and sweet varieties of maize. 
sperms represent an imperfect development through the loss or fail- 
ure of some element or hereditary factor and that what is lacking 
in the sweet is supphed by the waxy, and vice versa. It has often 
been suggested that sweet endosperm resulted from a failure of com- 
plete development of horny endosperm, but no suggestion has been 
made regarding the nature of the deficiency. It now appears that 
what is lacking in a sweet variety is supplied by the waxy, and, con- 
[Cir. 120] 
