IN THE TROPICS. 
375 
Out of 55 F 2 plants 17 were reckoned to bear seeds of the spherical 
or No. 1 type in narrower pods, whilst 36 bore seeds of the Telegraph 
type in wider pods. Actual measurements were not made and the 
distinction was not very clear. 
In F 3 , 134 plants were raised, offspring of 7 plants which proved 
the most prolific in F 2 . Of the 7, 2 included only plants with 
moderately narrow pods (but wider and more variable than those of 
No. 1) ; and these bore seeds which were all nearly spherical, but 
variable in size from plant to plant, being on the average larger 
than those of No. 1. These two families were the offspring of 
plants which had been reckoned as bearing seeds of the No. 1 type 
in F 2 . 
Of the other five families—offspring of seeds of more or less the 
Telegraph type—two consisted wholly of plants with pods and 
seeds of the Telegraph type whilst the other three included both types. 
In two of these cases the proportion of the two types (Telegraph : 
No. 1) could be distinguished as 13 : 4 and 10 : 2 ; in the third case 
there was more variability. 
There thus appears to be Mendelian segregation to a certain extent 
in respect of the characters wide or narrow pod correlated with 
certain shapes of seeds. But the extracted “ récessives 55 seem still 
to show r signs of the influence of the more or less dominant form 
(wider pods). So that there is perhaps more complication than in a 
simple Mendelian case. One source of complication is patent in the 
fact that the size of seeds appears to be a character independent of 
their shape. Possibly there is also in some cases a mutual influence 
between size of seeds and width of pods. 
On the other hand, colour of the cotyledons, which was the 
character to which attention was chiefly directed in the present 
experiment, was found to gain in distinctness as the result of the cross 
and to obey Mendel’s law with the utmost precision. The green 
and yellow seeds obtained from heterozygotes in F 2 and F 3 showed, 
when looked at in bulk, a most marked uniformity among themselves 
and distinctness from the other type. When kept for some weeks the 
colour of the green seeds especially became duller, and a tinge of 
yellow began to appear in some of them. 
