INHERITANCE OF WAXY ENDOSPERM IN MAIZE. 9 
For the ears in the accompanying graph the calculated standard 
deviation is 1.95, and the observed standard deviation is 3.11. The 
difference is 8.5 times the probable error. 
Since 45 of the individual ears represent crosses between the 
Chinese variety and horny varieties other than the Algeria, it may — 
be well to examine the curve without these ears. Omitting these 
45 ears, the standard deviation is reduced to 2.5, the mean remain- 
ing unchanged at 23.9. The theoretical standard deviation is also 
slightly reduced. The difference is now 5.2 times the probable error, 
a difference still too large to be ascribed to chance. 
Thus while the mean percentage of waxy seeds reappearing in 
the second generation of waxy < horny hybrids is 23.9, which is too 
large a deviation from 25 per cent to be ascribed to chance, the indi- 
vidual ear approximations are not sufficiently close to the observed 
mean to be considered as chance departures from it. The explana- 
tion that at once presents itself is that through mistakes in classifica- 
tion a varying number of waxy seeds were being included in the 
horny group. 
Endosperm texture is not subject to the minute spotting encoun- 
tered in the aleurone’color, and in the series of crosses here reported 
the classes were unusually good, owing to the fact that the Algeria 
parent was a pop corn and had a minimum of soft starch. Two 
instances where the endosperm was part horny and part waxy have 
been reported (5) and four additional seeds have since been found. 
When these mosaic seeds were planted and self-pollinated, they be- 
haved as normal seeds heterozygous for horny endosperm. 
Since mosaic endosperms are known to occur, it is of course con- 
ceivable that the horny or waxy portion of the seeds may be so 
reduced as to escape detection, but since such seeds are heterozygous, 
the only result could be to erroneously class heterozygous seeds as 
waxy, but this would increase rather than diminish the number of 
seeds classed as waxy. 
A deficiency in the number of individuals with the recessive 
character does not readily admit of the explanation that the devia- 
tion is due to mistakes in classification. Such an explanation would 
require that some of the individuals exhibiting the dominant char- 
acter were in reality homozygous recessives. Where a deficiency in 
the number of individuals with the dominant character occurs, such 
deviation could be the result of mistakes in classification, since it is 
conceivable that a failure or a partial failure of dominance results in 
some individuals exhibiting the dominant character to such a slight 
degree as to pass for homozygous recessives. If waxy seeds were 
being included in the horny group, some all-waxy ears would be se- 
cured in self-pollinating plants grown from the horny seeds. 
