Table 3/23.  Digitalis purpurea.

The tallest Flower-stem on each Plant measured in inches:  0 means that the Plant died before a Flower-stem was produced.

Column 1:  Number (Name) of Pot.

Column 2:  Crossed Plants.

Column 3:  Self-fertilised Plants.

Pot 1 :  53 6/8 :  27 4/8. 
Pot 1 :  57 4/8 :  55 6/8. 
Pot 1 :  57 6/8 :  0. 
Pot 1 :  65 :  0.

Pot 2 :  34 4/8 :  39. 
Pot 2 :  52 4/8 :  32. 
Pot 2 :  63 6/8 :  21.

Pot 3 :  57 4/8 :  53 4/8. 
Pot 3 :  53 4/8 :  0. 
Pot 3 :  50 6/8 :  0. 
Pot 3 :  37 2/8 :  0.

Pot 4 :  64 4/8 :  34 4/8. 
Pot 4 :  37 4/8 :  23 6/8. 
Pot 4 :  —­ :  0.

Pot 5 :  53 :  0. 
Pot 5 :  47 6/8 :  0. 
Pot 5 :  34 6/8 :  0.

Total :  821.25 :  287.00.

The average height of the flower-stems of the sixteen crossed plants is here 51.33 inches; and that of the eight self-fertilised plants, 35.87; or as 100 to 70.  But this difference in height does not give at all a fair idea of the vast superiority of the crossed plants.  These latter produced altogether sixty-four flower-stems, each plant producing, on an average, exactly four flower-stems, whereas the eight self-fertilised plants produced only fifteen flower-stems, each producing an average only of 1.87 stems, and these had a less luxuriant appearance.  We may put the result in another way:  the number of flower-stems on the crossed plants was to those on an equal number of self-fertilised plants as 100 to 48.

Three crossed seeds in a state of germination were also planted in three separate pots; and three self-fertilised seeds in the same state in three other pots.  These plants were therefore at first exposed to no competition with one another, and when turned out of their pots into the open ground they were planted at a moderate distance apart, so that they were exposed to much less severe competition than in the last case.  The longest leaves on the three crossed plants, when turned out, exceeded those on the self-fertilised plants by a mere trifle, namely, on an average by .17 of an inch.  When fully grown the three crossed plants produced twenty-six flower-stems; the two tallest of which on each plant were on an average 54.04 inches in height.  The three self-fertilised plants produced twenty-three flower-stems, the two tallest of which on each plant had an average height of 46.18 inches.  So that the difference between these two lots, which hardly competed together, is much less than in the last case when there was moderately severe competition, namely, as 100 to 85, instead of as 100 to 70.

The effects on the offspring of intercrossing different flowers on the
same plant, instead of crossing distinct individuals.