‘ 
88 BULLETIN 754, U. S. DEPARTMENT OF AGRICULTURE. 
secured was 0.1730.063 on ear No. 1833, which can not be considered 
significant, being less than three times the probable error. 
The results obtained from the progeny of the two ears, Nos. 1129 
and 1130, of the hybrid Dh 237 were, with a few exceptions, fairly 
close approximations of the expected results on the assumption that 
the gametes were formed in a series of 3-1-1-3. 
SECOND GENERATION OF THE CROSSES BETWEEN THE TWO 
HYBRIDS DH 234 AND DH 237. 
Aside from the two first-generation hybrids between the Algeria 
and the Chinese varieties of maize, Dh 234 and Dh 237, and their im- 
mediate progeny, the result of self-pollination or crosses between two 
plants of the same hybrid there were 34 ears, the result of crossing 
the two first-generation hybrids. Seventeen of these ears were all 
colored with both horny and waxy seeds. 
Three of these all-colored ears were grown the following season. 
One ear, resulting from using the hybrid Dh 234 as the female 
parent and the hybrid Dh 237 as the male parent, was renum- 
bered cross Dh 330 and grown under that symbol. The other two 
ears grown were the result of using the hybrid Dh 237 as the 
female parent and the hybrid Dh 234 as the male parent. These 
two ears were known as crosses Dh 333 and Dh 334. The female 
parent of the cross Dh 333 was used as the male parent of the cross 
Dh 330. 
On each of these three all-colored ears there are 16 classes of 
zygotes, only 6 of which will exhibit, when self-pollinated, ears with 
all 4 classes of seeds, colored and white horny and colored and white 
waxy. 
All 6 of these classes of zygotes when planted and self-pollinated 
are expected to have horny and waxy seeds in the proportion of 3 to 1, 
while 4 of the 6 are expected to have colored and white in the pro- 
portion of 3to1. The remaining 2 classes are expected to have colored 
and white seeds in the proportion of 9 to 7. 
For the 6 classes of zygotes, 4 very different degrees of correla- 
tion are expected, in the following proportions: Four ears with no 
correlation between the colored aleurone and horny endosperm, 3 
ears with a correlation of 0.766 between colored aleurone and horny 
endosperm, one with a correlation of 0.744 between colored aleurone 
and waxy endosperm, and one with a correlation of 0.380 between 
colored aleurone and waxy endosperm. Of the 16 zygotic combina- 
tions represented on the all-colored ears, only 2 classes of seeds could 
be distinguished, namely, horny and waxy. These were planted 
separately. 
