34 
ORLAND E. WHITE 
(-4-1 A) plant, a large amount of "open field " seed was gathered from it. 
Thousands of hybrid F2 segregates of various crosses such as N. 
forgetiana X N. alata and N. alata X N, langsdorffii were grown in the 
same field, and in the same year as the -4-1 A parent. These were all 
normal in respect to catacorolla, excepting the 15 plants already men- 
tioned. Cross-fertilization was more favorable to the production of 
seed on this one (-4-1 A) selection than self-fertilization. This means 
that the open field seed would produce largely hybrid Fi plants. 
One hundred and sixty-two plants grown from this seed gave 43 
homozygous 4-1 A progeny and 119 hybrid Fi progeny, the latter 
representing almost as many different Fi combinations as there were 
individuals. As a consequence, they were extremely variable in 
almost every taxonomic feature, — in habit, height, foliage; in flower 
color, size and shape ; in pollen color, and in many other less prominent 
characters. Sixty of the 119 were colored, and 59 were white. Some 
of the flowers were as small as those of N. forgetiana, while others were 
as large as those of N. alata. Fig. 4 is an attempt to show something 
of these differences in flower size, as well as in the variability of the 
catacorolla character. Each flower represents a single plant. The Fi 
variation in the expression of the catacorolla was remarkable. Sup- 
posedly each of the 119 plants represented a different genotypical 
complex, and hence one would, on the conception of dominance 
supported by East, expect a great deal of variability. Table 6 shows 
the results of classifying the whole 162 progeny by color and by their 
expression of the anomaly. 
Table 6 
-4- 1 A 
Hybrids 
Color 
Pure Homozygote 
Intermediate 
Normal 
Total 
White 
A 43 
33 
26 
102 
Colored ..... 
II 
49 
60 
43 
44 
75 
162 
Those classified as normals showed absolutely no expression .of the 
character. 
Guarded crosses were made between the -4-1A and -2-1A strains. 
The genotypical constitutions were very difficult, as each had a dis- 
tinct growth habit, leaf size, etc. About 150 Fi plants were grown in 
the same field and under approximately the same conditions as the 
other "catacorolla" cultures. In this cross, the Fi expression of 
catacorolla was intermediate, with a fluctuation towards complete 
i 
