A fine plant growing in my garden (one of the foregoing seedlings) was covered with a net, and six flowers were crossed with pollen from another flower on the same plant, and six others were fertilised with their own pollen.  All produced good capsules.  The seeds from each were placed in separate watch-glasses, and no difference could be perceived by the eye between the two lots of seeds; and when they were weighed there was no difference of any significance, as the seeds from the self-fertilised capsules weighed 7.65 grains, whilst those from the crossed capsules weighed 7.7 grains.  Therefore the sterility of the present species, when insects are excluded, is not due to the impotence of pollen on the stigma of the same flower.  Both lots of seeds and seedlings were treated in exactly the same manner as in Table 3/23, excepting that after the pairs of germinating seeds had been planted on the opposite sides of eight pots, all the remaining seeds were thickly sown on the opposite sides of Pots 9 and 10 in Table 3/24.  The young plants during the following spring were turned out of their pots, without being disturbed, and planted in the open ground in two rows, not very close together, so that they were subjected to only moderately severe competition with one another.  Very differently to what occurred in the first experiment, when the plants were subjected to somewhat severe mutual competition, an equal number on each side either died or did not produce flower-stems.  The tallest flower-stems on the surviving plants were measured, as shown in Table 3/24.

Table 3/24.  Digitalis purpurea.

The tallest Flower-stem on each Plant measured in inches:  0 signifies that the Plant died, or did not produce a Flower-stem.

Column 1:  Number (Name) of Pot.

Column 2:  Plants raised from a Cross between different Flowers on the same Plant.

Column 3:  Plants raised from Flowers fertilised with their own Pollen.

Pot 1 :  49 4/8 :  45 5/8. 
Pot 1 :  46 7/8 :  52. 
Pot 1 :  43 6/8 :  0.

Pot 2 :  38 4/8 :  54 4/8. 
Pot 2 :  47 4/8 :  47 4/8. 
Pot 2 :  0 :  32 5/8.

Pot 3 :  54 7/8 :  46 5/8.

Pot 4 :  32 1/8 :  41 3/8. 
Pot 4 :  0 :  29 7/8. 
Pot 4 :  43 7/8 :  37 1/8.

Pot 5 :  46 6/8 :  42 1/8. 
Pot 5 :  40 4/8 :  42 1/8. 
Pot 5 :  43 :  0.

Pot 6 :  48 2/8 :  47 7/8. 
Pot 6 :  46 2/8 :  48 3/8.

Pot 7 :  48 5/8 :  25. 
Pot 7 :  42 :  40 5/8.

Pot 8 :  46 7/8 :  39 1/8.

Pot 9 :  49 :  30 3/8. 
Pot 9 :  50 3/8 :  15. 
Pot 9 :  46 3/8 :  36 7/8. 
Pot 9 :  47 6/8 :  44 1/8. 
Pot 9 :  0 :  31 6/8. 
Crowded Plants.

Pot 10 :  46 4/8 :  47 7/8. 
Pot 10 :  35 2/8 :  0. 
Pot 10 :  24 5/8 :  34 7/8. 
Pot 10 :  41 4/8 :  40 7/8. 
Pot 10 :  17 3/8 :  41 1/8. 
Crowded Plants.