48 
Research Bulletin A o. 2 
ear (60-5x54) 12-1ES, which was itself 9 cm. long, was 10.0 ± .12 
cm. The average of the progeny of ear (60-5x54) -12-2ES, an ear 
of 9 cm. long, was 9.2 ± .07. These families of short ears con- 
trast noticeably with the family produced by ear (60-5x54) -1 1-2 AS 
an ear 18 cm. long, for this family averaged 15.8 ± .13 cm. In 
fact, the extreme variates of the shortest family and the longest 
family scarcely overlap. 
Cross (60-8x54) is notable for the extreme variability of F ... 
Two families were grown, in which the coefficients of variability 
were 14.80 ± .69 per cent and 18.95 ± .89 per cent respectively. 
The total number of F 2 individuals gave a coefficient of variabil- 
ity of 17.44 ±: .41 per cent. It happened that no long F 2 ears 
were selfed in this cross. Two medium length ears were grown 
primarily for other purposes, however, and their progeny 
measured. One family was very short, averaging 9.3 ± .07 cm. 
and the other family very variable, showing a coefficient of 
variability of 21.52 ±1.23. 
The data for ear length in the cross of Tom Thumb with 
Missouri dent are given in Table 16. As in the case of number 
of rows, the parents and F x are represented by measurements 
taken from ears kept for samples. The records of the F t gen- 
eration grown in 1910 were accidently destroyed and no F x was 
grown in 1911. The Missouri dent, owing to its lateness of 
maturity, did not ripen in 1911 and Tom Thumb produced few 
ears that year. As a matter of fact the samples preserved 
represent the parents and ¥ 1 fairly well. The F t ears as a 
whole were practically as long as those of Missouri dent. The 
F 2 families differed in ear length as they did in other characters 
to be noted later. The parent stocks evidently were heterozygous 
in some factors influencing ear length. None of the F 2 ears were 
as short as the average Tom Thumb pop ear but many were 
shorter than any ears of Missouri dent or of the F 1 generation, 
The F 3 families, all of which came from a single F 2 family and 
therefore, from a single F 1 ear, differed noticeably in ear length. 
The shortest average length was a little over 10 centimeters and 
the longest a little over 18 centimeters. The longest ears of 
some families were only slightly longer than the shortest ears 
of other families. It seems probable that types of ear length 
like the parent types as well as various intermediate types could 
readily be established from this material. 
Table 17 includes all available data in regard to ear length 
from the cross of California pop with Missouri dent. F x families 
502 and 505 were grown under fairly favorable weather condi- 
tions in 1910, while all the other families listed were grown 
under the conditions of extreme drouth prevailing at Lincoln. 
Nebraska, in 191.1. The general appearance of the Missouri 
