A BRACHYTIC VARIATION IN MAIZE. 



23 



character in half the cases. In this particular cross also the spikes 

 were unusually well developed. (See Table IV.) 



BRACHYTIC X HOPI. 



The Hopi variety, in common with other varieties grown by the 

 Indians of the Southwestern States, possesses the long mesocotyl, 

 which permits deep planting. An attempt was made by crossing 

 brachytic and Hopi to combine the brachytic stature with the deep- 

 planting adaptation. The strain of Hopi used in this cross was par- 

 ticularly vigorous, with plants fully as tall as those of the Boone 

 variety. 



The first generation was a complete surprise and was practically 

 worthless. The plants were tall but differed from all the other first- 

 generation hybrids of which brachytic was one parent in that they 

 were weak and soon lodged. The ears were small and the yield poor. 



Table IV. — Distribution of plants with respect to the staminate spike characters 

 in the brachytic X Boone and brachytic X Hopi hybrids of maize, including 

 plants of the first and second generations. 



Progeny designation. 



Normal 

 stature. 



Nor- 

 mal 

 ears. 



Ears 

 with 



c? 

 spikes 



Brachytic 

 stature. 



Nor- 

 mal 

 ears. 



Ears 

 with 



<? 

 spikes 



Total. 



Percentage. 



Bra- 



chyt- 



Stami- 



nate 



spikes. 



Coefficient 

 of asso- 

 ciation. 1 



Brachytic X Boone: 

 Dh436W2L19, F 2 

 Dh435WlL19, F 2 

 Dh436WlLl9, F 2 



Total :.... 



Dh436F! 



Brachvtic X Hopi: 

 Dh 438 Wl L19, F 2 

 Dh438Fi 



83 

 103 



84 



27.7 

 31.0 

 21.4 



33.8 

 24.3 

 21.4 



0. 10±0.20 

 .45±0. 17 

 1.0 ±0 



12 



270 



27.0 



.37±0. 112 



23.2 



21.3 



13.7 

 9.1 



.91±0.04 



1 The correlations are between normal stature and staminate spikes with the exception of the last one, 

 which is a correlation between brachytic stature and staminate spikes. 



The second generation was little better, and no good plants were 

 found. The brachytic plants especially were poor, one-half of the 

 plants having ears which terminated in the staminate spikes found in 

 the brachytic-Boone hybrids and described on pages 20-22. In the 

 Hopi hybrid, however, the staminate spikes were much longer in pro- 

 portion to the length of the pistillate part. The magnitude of this 

 difference between the pistillate and staminate parts is shown in 

 Table V. In the other hybrids the staminate spikes on the ears of 

 brachytic plants were no longer than those borne on sister plants of 

 normal stature. The ears with staminate spikes in the Hopi hybrid 

 contrasted sharply with the normal ears, and no gradations were 

 found. In this respect they differed from the Boone hybrids, where 



