CHAP. IIL FLOWERS ON SAME PLANT CEOSSED. 75 



Weight of seed produced by the same number ) ,, inn to 3 



of Chelsea-crossed and self-fertilised plants 

 Weight of seeds produced by the same number ) , QQ ^ 



of intercrossed and self-fertilised plants . . f 



It is also a remarkable fact that the Chelsea-crossed plants 

 exceeded the two other lots in hardiness, as greatly as they did 

 in height, luxuriance, and fertility. In the early autumn most of 

 the pots ..were bedded out in the open ground ; and this always 

 injures plants which have been long kept in a warm greenhouse. 

 All three lots consequently suffered greatly, but the Chelsea- 

 crossed plants much less than the other two lots. On the 3rd of 

 October the Chelsea-crossed plants began to flower again, and 

 continued to do so for some time ; whilst not a single flower was 

 produced by the plants of the other two lots, the stems of which 

 were cut almost down to the ground and seemed half dead. 

 Early in December there was a sharp frost, and the stems of 

 Chelsea-crossed were now cut down ; but on the 23rd of December 

 they began to shoot up again from the roots, whilst all the plants 

 of the other two lots were quite dead. 



Although several of the self-fertilised seeds, from which the 

 plants in the right-hand column in Table XX. were raised, germi- 

 nated (and were of course rejected) before any of those of the 

 other two lots, yet in only one of the ten pots did a self- 

 fertilised plant flower before the Chelsea-crossed or the inter- 

 crossed plants growing in the same pots. The plants of these 

 two latter lots flowered at the same time, though the Chelsea- 

 crossed grew so much taller and more vigorously than the 

 intercrossed. 



As already stated, the flowers of the plants originally raised 

 from the Chelsea seeds were yellow ; and it deserves notice that 

 every one of the twenty-eight seedlings raised from the tall 

 white variety fertilised, without being castrated, with pollen 

 from the Chelsea plants, produced yellow flowers; and this 

 shows how prepotent this colour, which is the natural one of 

 the species, is over the white colour. 



The Effects on the Offspring of intercrossing Flowers on the 

 same Plant, instead of crossing distinct Individuals. In all the 

 foregoing experiments the crossed plants were the product of a 

 cross between distinct plants. I now selected a very vigorous 

 plant in Table XX., raised by fertilising a plant of the eighth 

 self-fertilised generation with pollen from the Chelsea stock, 



