Chap. VIII. ON SELF-FERTILISED PLANTS. 307 



of their flowers. This occurs with many plants which 

 have been long cultivated as an ornament for the 

 flower-garden, and which have been propagated by 

 seeds. The colour of the flowers was a point to which 

 I did not at first in the least attend, and no selection 

 whatever was practised. Nevertheless, the flowers 

 produced by the self-fertilised plants of the above 

 four species became absolutely uniform in tint, or very 

 nearly so, after they had been grown for some gene- 

 rations under closely similar conditions. The inter- 

 crossed plants, which were more or less closely 

 inter-related in the later generations, and which had 

 been likewise cultivated all the time under similar 

 conditions, became more uniform in the colour of 

 their flowers than were the original parent-plants, but 

 much less so than the self-fertilised plants. When 

 self-fertilised plants of one of the later generations 

 were crossed with a fresh stock, and seedlings thus 

 raised, these presented a wonderful contrast in the 

 diversified tints of their flowers compared with those of 

 the self-fertilised seedlings. As such cases of flowers 

 becoming uniformly coloured without any aid from 

 selection seem to me curious, I will give a full 

 abstract of my observations. 



Mimulus luteus. A tall variety, bearing large, almost 

 white flowers blotched with crimson, appeared amongst 

 the intercrossed and self-fertilised plants of the third 

 and fourth generations. This variety increased so 

 rapidly, that in the sixth generation of self-fertilised 

 plants every single one consisted of it. So it was 

 with all the many plants which were raised, up to the 

 last or ninth self-fertilised generation. Although this 

 variety first appeared amongst the intercrossed plants, 

 yet from their offspring being intercrossed in each 

 succeeding generation, it never prevailed amongst 



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