408 
LOCK : STUDIES IN PLANT BREEDING 
In F 3 the plants with long and those with short internodes were 
readily distinguishable two or three weeks after germination. At 
this time the former were, as a rule, quite twice as tall as the latter and 
perfectly distinct in appearance. The offspring of the 10 heterozy¬ 
gotes was as follows in F s , the counting being made 18 days after 
germination. A considerable number of these plants subsequently 
perished from drought, and a few had already died since germination, 
the mortality being greater in the case of the dwarf form :— 
No. 
Tall. 
Dwarf. 
No. 
Tall. 
Dwarf. 
439.1 
12 
. . 5 
440.10 
28 
. . 4 
.4 
48 
14 
.12 
23 
8 
.6 
74 
16 
.13 
5 
4 
440.2 
5 
4 
.14 
6 
1 
.3 
22 
3 
.15 
31 
13 
Total—245 tall to 72 dwarf, or 3 53: 1. The two groups are 
unmistakably distinct, the dwarf forms having a much stiffer 
appearance and foliage somewhat darker than the tall. 
Length of life was found to be a character quite independent of the 
above, and is one which may considerably modify the final height of 
the plant. Thus, in the case of No. 440T6 ; flowers did not appear 
before the 48th internode. The offspring of this plant, which resem¬ 
bled the parent, all fell victims to excessively wet weather before any 
flowers appeared ; most of them had by that time developed about 
40 internodes. It is a remarkable fact that none of the tall or dwarf 
forms in F 2 and F 3 were in the least like either of the original 
parents, in both of which the internodes seemed to be of medium 
length. In F t there appeared a form with longer internodes than 
either parent, and in F 2 this form persisted as a dominant type, 
whilst a new recessive form appeared with shorter internodes than 
either parent. 
As regards the shape of seeds in F 5 and F s , the phenomena obser- 
ved may be briefly summed up as follows Seeds with a coloured 
testa were dimpled or wrinkled according to Mendel’s law, although 
the difficulty of exact discrimination made it impossible to ascertain 
the precise ratio in more than a few cases. Small seeds were as a 
rule less dimpled than large ones, so that some of the smallest of the 
