Table 2/1.  Ipomoea purpurea (First Generation.).

Heights of Plants in inches: 

Column 1:  Number (Name) of Pot.

Column 2:  Seedlings from Crossed Plants.

Column 3:  Seedlings from Self-fertilised Plants.

Pot 1 :  87 4/8 :  69. 
Pot 1 :  87 4/8 :  66. 
Pot 1 :  89 :  73.

Pot 2 :  88 :  68 4/8. 
Pot 2 :  87 :  60 4/8.

Pot 3 :  77 :  57. 
Plants crowded; the tallest one measured on each side.

Total :  516 :  394.

The average height of the six crossed plants is here 86 inches, whilst that of the six self-fertilised plants is only 65.66 inches, so that the crossed plants are to the self-fertilised in height as 100 to 76.  It should be observed that this difference is not due to a few of the crossed plants being extremely tall, or to a few of the self-fertilised being extremely short, but to all the crossed plants attaining a greater height than their antagonists.  The three pairs in Pot 1 were measured at two earlier periods, and the difference was sometimes greater and sometimes less than that at the final measuring.  But it is an interesting fact, of which I have seen several other instances, that one of the self-fertilised plants, when nearly a foot in height, was half an inch taller than the crossed plant; and again, when two feet high, it was 1 3/8 of an inch taller, but during the ten subsequent days the crossed plant began to gain on its antagonist, and ever afterward asserted its supremacy, until it exceeded its self-fertilised opponent by 16 inches.

The five crossed plants in Pots 1 and 2 were covered with a net, and produced 121 capsules; the five self-fertilised plants produced eighty-four capsules, so that the numbers of capsules were as 100 to 69.  Of the 121 capsules on the crossed plants sixty-five were the product of flowers crossed with pollen from a distinct plant, and these contained on an average 5.23 seeds per capsule; the remaining fifty-six capsules were spontaneously self-fertilised.  Of the eighty-four capsules on the self-fertilised plants, all the product of renewed self-fertilisation, fifty-five (which were alone examined) contained on an average 4.85 seeds per capsule.  Therefore the cross-fertilised capsules, compared with the self-fertilised capsules, yielded seeds in the proportion of 100 to 93.  The crossed seeds were relatively heavier than the self-fertilised seeds.  Combining the above data (i.e., number of capsules and average number of contained seeds), the crossed plants, compared with the self-fertilised, yielded seeds in the ratio of 100 to 64.

These crossed plants produced, as already stated, fifty-six spontaneously self-fertilised capsules, and the self-fertilised plants produced twenty-nine such capsules.  The former contained on an average, in comparison with the latter, seeds in the proportion of 100 to 99.