126 



VIOLA TRICOLOR. 



CHAP. IV. 



height of the self-fertilised, generally flowered first, and produced 

 ten times as many naturally fertilised capsules. 



TABLE XLL 



Viola tricolor. 



By the early part of the summer of 1870 the crossed plants in 

 all the five clumps had grown and spread so much more than 

 the self-fertilised, that any comparison between them was 

 superfluous. The crossed plants were covered with a sheet of 

 bloom, whilst only a single self-fertilised plant, which was much 

 finer than any of its brethren, flowered. The crossed and self- 

 fertilised plants had now grown all matted together on the 

 respective sides of the superficial partitions still separating them ; 

 and in the clump which included the finest self-fertilised plant, 

 I estimated that the surface covered by the crossed plants was 

 about nine times as large as that covered by the self-fertilised 

 plants. The extraordinary superiority of the crossed over the 

 self-fertilised plants in all five clumps, was no doubt due to 

 the crossed plants at first having had a decided advantage over 

 the self-fertilised, and then robbing them more and more of their 

 faod during the succeeding seasons. But we should remember 



