CHAP. V LOBELIA FULGENS. 179 



LOBELIA FULGENS. 



This species offers a somewhat perplexing case In the first 

 generation the self-fertilised plants, though few in number, 

 greatly exceeded the crossed in height ; whilst in the second 

 generation, when the trial was made on a much larger scale, 

 the crossed beat the self-fertilised plants. As this species 

 is generally propagated by off-sets, some seedlings were first 

 raised, in order to have distinct plants. On one of these plants 

 several flowers were fertilised with their own pollen ; and as the 

 pollen is mature and shed long before the stigma of the same 

 flower is ready for fertilisation, it was necessary to number each 

 flower and keep its pollen in paper with a corresponding number. 

 By this means well-matured pollen was used for self-fertilisation. 

 Several flowers on the same plant were crossed with pollen from 

 a distinct individual, and to obtain this the conjoined anthers of 

 young flowers were roughly squeezed, and as it is naturally 

 protruded very slowly by the growth of the pistil, it is probable 

 that the pollen used by me was hardly mature, certainly less 

 mature than that employed for self-fertilisation. I did not at 

 the time think of this source of error, but I now suspect that 

 the growth of the crossed plants was thus injured. Anyhow the 

 trial was not perfectly fair. Opposed to the belief that the 

 pollen used in crossing was not in so good a state as that used 

 for self-fertilisation, is the fact that a greater proportional number 

 of the crossed than of the self-fertilised flowers produced cap- 

 sules; but there was no marked difference in the amount of seed 

 contained in the capsules of the two lots.* 



As the seeds obtained by the above two methods would not 

 germinate when left on bare sand, they were sown on the 

 opposite sides of four pots ; but I succeeded in raising only a 

 single pair of seedlings of the same age in each pot. The self- 

 fertilised seedlings, when only a few inches in height, were in 

 most of the pots taller than their opponents ; and they flowered 

 so much earlier in all the pots, that the height of the flower- 

 stems could be fairly compared only in Pots I. and II. 



* Gartner has shown that cer- but none of the plants on which 



tain plants of Lobelia fulgens are I experimented, which were kept 



quite sterile with pollen from the in the greenhouse, were in this 



same plant, though this pollen is peculiar condition, 

 efficient on any other individual ; 



H 2 



