SELF-FERTILIZATION OF PLANTS. 889 
plants exhibited astonishing vigour. Thus he speaks of the white or pale-coloured 
variety of Mimulus luteus (l.c. p. 80) :— 
“ From the tallness of this variety, the self-fertilised plants exceeded the crossed plants in height in all 
the generations from the fifth to the seventh inclusive; and no doubt would have done so in the later 
generations, had they been grown in competition with one another.’ [My italics.] 
Again, of Hero, the sixth self-fertilized generation of Ipomea, he says :— 
“If the seeds produced by Hero had been as greatly in excess of those produced by the other plants 
as was the case with Mimulus, and if all the seeds had been mingled together, the offspring of Hero would 
have increased to the entire exclusion of the ordinary plants in the later self-fertilised generations, and 
from naturally growing taller would have exceeded the crossed plants in height in each succeeding 
generation." 
I quote these passages, for they show that, according to Mr. Darwin's estimation, 
these self-fertilized varieties would have been superior to others under competition, a fact 
which, as a rule, is opposed to the results of his experiments, as he, indeed, observes :— 
“ Thus we have a complete reversal of what occurred in the previous generation." The 
interpretation appears to be that they found certain ingredients in the soil which suited 
and strengthened their constitutions, and so they gained independently what was usually 
only to be acquired by means of a cross with a distinct stock; which seems to prove that 
if a self-fertilizing plant can secure new constitutional elements from a fresh soil, it then 
may show as much vigour as, or more than, one which may be intererossed with another 
plant growing under the same conditions. 
On the other hand, Mr. Darwin mentions some instances where the self-fertilized 
appeared to him to have actually suffered from self-fertilization. This, he thinks, was 
shown indirectly by the intercrossed plants withstanding certain adverse conditions, 
while the self-fertilized failed to do so; thus he says (l. c. p. 289), ** The crossed plants 
always withstood the injurious effects of being suddenly removed into the open air after 
having been kept in the greenhouse better than did the self-fertilised. On several occa- 
sions they also resisted much better cold and intemperate weather . . . . The offspring 
of plants of the eighth self-fertilised generation of Mimulus, crossed by a fresh stock, 
survived a frost which killed every single self-fertilised and intercrossed plant of the 
same old stock. Nearly the same result followed with some crossed and self-fertilised 
plants of Viola tricolor .. ... I have met with only one exception to the rule of crossed 
plants being hardier than the self-fertilised [that of EscAscholtzia]. . ... Independently 
of any external cause which could be detected, the self-fertilised plants were more liable 
to premature death than were the crossed.” A few further remarks will be found in 
l. c. pp. 290-1*. But allowing for these facts, which occurred under cultivation, self-fertili- 
zation, as carried on by Nature, does not support them. This, for example, is shown by 
such of our wild flowers as blossom in mild winters being (after eliminating any anemo- - 
philous cases) probably, without exception, self-fertilized. They can and do ripen their 
seeds in profusion in January as well as in July, and in that respect show a vast superiority 
over those plants which have to depend upon the visits of insects to set seeds at all. They 
iy EE ET slag 
Fertilization of Plants," in the ‘Gardeners’ Chronicle,’ —5 RA 
uno ee T SE i os 
