in the two Pots 2 and 5 were kept separate, and when fully grown were measured to the tips of their highest leaves, as shown in Table 6/88.  But as there was no uniform difference in height between the crossed and self-fertilised seedlings raised from the two plants, their heights have been added together in calculating the averages.  I should state that by the accidental fall of a large bush in the greenhouse, several plants in both the series were much injured.  These were at once measured together with their opponents and afterwards thrown away.  The others were left to grow to their full height, and were measured when in flower.  This accident accounts for the small height of some of the pairs; but as all the pairs, whether only partly or fully grown, were measured at the same time, the measurements are fair.

The average height of the twenty-six crossed plants in the sixteen pots of the two series is 63.29, and that of the twenty-six self-fertilised plants is 41.67 inches; or as 100 to 66.  The superiority of the crossed plants was shown in another way, for in every one of the sixteen pots a crossed plant flowered before a self-fertilised one, with the exception of Pot 6 of the second series, in which the plants on the two sides flowered simultaneously.

Table 6/88.  Nicotiana tabacum.  Plants raised from two plants of the third self-fertilised generation in Pots 2 and 5, in Table 6/87.

Heights of plants measured in inches.

Column 1:  Number (Name) of Pot.

Column 2:  Kew-crossed Plants, pot 2, Table 6/87.

Column 3:  Plants of the fourth Self-fertilised generation, pot 2, Table 6/87.

Column 4:  Kew-crossed Plants, pot 5, Table 6/87.

Column 5:  Plants of the fourth Self-fertilised generation, pot 5, Table 6/87.

Pot 1 :  84 6/8 :  68 4/8 :  77 6/8 :  56. 
Pot 1 :  31 :  5 :  7 2/8 :  5 3/8.

Pot 2 :  78 4/8 :  51 4/8 :  55 4/8 :  27 6/8. 
Pot 2 :  48 :  70 :  18 :  7.

Pot 3 :  77 3/8 :  12 6/8 :  76 2/8 :  60 6/8. 
Pot 3 :  77 1/8 :  6 6/8.

Pot 4 :  49 2/8 :  29 4/8 :  90 4/8 :  11 6/8. 
Pot 4 :  15 6/8 :  32 :  22 2/8 :  4 1/8.

Pot 5 :  89 :  85 :  94 2/8 :  28 4/8. 
Pot 5 :  17 :  5 3/8.

Pot 6 :  90 :  80 :  78 :  78 6/8.

Pot 7 :  84 4/8 :  48 6/8 :  85 4/8 :  61 4/8. 
Pot 7 :  76 4/8 :  56 4/8.

Pot 8 :  83 4/8 :  84 4/8 :  65 5/8 :  78 3/8. 
Pot 8 :  :  :  72 2/8 :  27 4/8.

Total :  902.63 :  636.13 :  743.13 :  447.38.

Some of the remaining seeds of both series, whether or not in a state of germination, were thickly sown on the opposite sides of two very large pots; and the six highest plants on each side of each pot were measured after they had grown to nearly their full height.  But their heights were much less than in the former trials, owing to their extremely crowded condition.  Even whilst quite young, the crossed seedlings manifestly had much broader and finer leaves than the self-fertilised seedlings.