Lastly, twelve flowers on the same self-fertilised plants of the third generation were crossed with pollen from plants which had been raised from seeds purchased in London.  It is almost certain that the plants which produced these seeds had grown under very different conditions to those to which my self-fertilised and crossed plants had been subjected; and they were in no degree related.  The above twelve flowers thus crossed all produced capsules, but these contained the low average of 37.41 seeds per capsule, with a maximum in one of sixty-four seeds.  It is surprising that this cross with a fresh stock did not give a much higher average number of seeds; for, as we shall immediately see, the plants raised from these seeds, which may be called the London-crossed, benefited greatly by the cross, both in growth and fertility.

The above three lots of seeds were allowed to germinate on bare sand.  Many of the London-crossed germinated before the others, and were rejected; and many of the intercrossed later than those of the other two lots.  The seeds after thus germinating were planted in ten pots, made tripartite by superficial divisions; but when only two kinds of seeds germinated at the same time, they were planted on the opposite sides of other pots; and this is indicated by blank spaces in one of the three columns in Table 4/47.  A 0 in the table signifies that the seedling died before it was measured; and a + signifies that the plant did not produce a flower-stem, and therefore was not measured.  It deserves notice that no less than eight out of the eighteen self-fertilised plants either died or did not flower; whereas only three out of the eighteen intercrossed, and four out of the twenty London-crossed plants, were in this predicament.  The self-fertilised plants had a decidedly less vigorous appearance than the plants of the other two lots, their leaves being smaller and narrower.  In only one pot did a self-fertilised plant flower before one of the two kinds of crossed plants, between which there was no marked difference in the period of flowering.  The plants were measured to the base of the calyx, after they had completed their growth, late in the autumn.

Table 4/47.  Dianthus caryophyllus.

Heights of plants to the base of the calyx, measured in inches.

Column 1:  Number (Name) of Pot.

Column 2:  London-Crossed Plants.

Column 3:  Intercrossed Plants.

Column 4:  Self-fertilised Plants.

Pot 1 :  39 5/8 :  25 1/8 :  29 2/8. 
Pot 1 :  30 7/8 :  21 6/8 :  +.

Pot 2 :  36 2/8 :  :  22 3/8. 
Pot 2 :  0 :  :  +.

Pot 3 :  28 5/8 :  30 2/8 :  . 
Pot 3 :  + :  23 1/8 :  .

Pot 4 :  33 4/8 :  35 5/8 :  30. 
Pot 4 :  28 7/8 :  32 :  24 4/8.

Pot 5 :  28 :  34 4/8 :  +. 
Pot 5 :  0 :  24 2/8 :  +.