te ee en ee a ee ee ee 
— 94) BULLETIN 754, U. S. DEPARTMENT OF AGRICULTURE. 
The self-pollinated colored horny ear had approximately 3 col- 
ored seeds to 1 white and a correlation of 0.628+0.054 between C 
and H. This correlation is about midway between that expected for 
self-pollinating circles 13 and 15, though it is slightly closer to the 
latter. Self-pollinating circle 15 would have an expected ratio of 
9 colored to 7 white seeds, but since the ear in question is a fairly 
close approximation to the ratio of 3 colored to 1 white it fits the 
expected proportions when circle 13 is self-pollinated. 
Assuming the plant in question to be the result of planting circle 
13, there are two classes of waxy seeds with which it may be crossed 
that will result in ears with four classes of seeds. These classes are 
represented by circles 14 and 16. 
The ears secured by either cross would be alike, both having 3 
colored seeds to 1 white and a correlation of 0.615 between C and H. 
Ear No. 1902, with a correlation of 0.640.038, is a close approxima- 
tion to the expected results on this basis, but the exact reciprocal ear, 
No. 1917, with a correlation of 0.348+0.067, can hardly be looked 
upon as approximating the expected 0.615. This correlation is much 
closer to that expected when circles 15 and 16 are crossed, but the 
ratio of white to colored seeds would in that case be as 7 to 9, and 
the observed ratio is a close approximation to the 3 to 1 ratio. In 
both the cases where the reciprocals differ in the degree of correla- 
tion the lowest correlation is found where the colored horny plant 
served as the female parent, indicating a higher correlation in the 
male gametes. This tendency has been observed with ear No. 1764 
(Table XX XVIII), where a significant difference was observed in 
_reciprocals, and also with ears Nos. 1804, 1815, and 1816 (Table 
XX XIX), where smaller differences in this direction were observed. 
This difference may be due to a higher death rate for the pollen 
grains bearing the character combinations resulting from different 
parents, or it may be that such pollen grains are less vigorous or that 
the male gametes are not being formed in the expected proportions. 
The remaining ear of cross Dh 330 that resulted from pollinating 
colored horny individuals by colored waxy is ear No. 1876. There 
is no reciprocal of this cross nor is there a self-pollinated ear from 
the colored horny parent. The ratio of white to colored seeds is 
rather closer to a 8 to 1 than a 7 to 9, and the correlation, 0.491 
+0.064, though low, may be looked upon as an approximation of 
the expected 0.615, when circles 13 and 16, 18 and 14, or 15 and 14 
are crossed. 
Of the three self-pollinated ears of the cross Dh 330, one ear, No. 
1875, has already been discussed. Ear No. 1878, having no signifi- 
cant correlation, could be the result of self-pollinating circles 4 or 
7, Ear No. 1882, with an approximate ratio of 9 colored to 7 white 
seeds and a correlation of 0.538 between ( and HZ, is a very close ap- 
