CHAK IX. CROSSED AND SELF-FERTILISED SEEDS. 353 



Specnlaria speculum as 100 to 86 



Nemophila insignis 105 



Borago officinalis 111 



Cyclamen persicum (about) 50 



Fagopyrum esculentum 82 



Canna warscewiczi (three generations) 102 



It is remarkable that in ten out of these sixteen 

 cases the self-fertilised seeds were either superior or 

 equal to the crossed in weight ; nevertheless, in six out 

 of the ten cases (viz., with Ipomcea, Salvia, Brassica, 

 Tropaeolum, Lathyrus, and Nemophila; the plants 

 raised from these self-fertilised seeds were very inferior 

 in height and in other respects to those raised from the 

 crossed seeds. The superiority in weight of the self- 

 fertilised seeds in at least six out of the ten cases, 

 namely, with Brassica, Hibiscus, Tropaeolum, Nemophila, 

 Borago, and Canna, may be accounted for in part by 

 the selMertilised capsules containing fewer seeds ; for 

 when a capsule contains only a few seeds, these will be 

 apt to be better nourished, so as to be heavier, than 

 when many are contained in the same capsule. It 

 should, however, be observed that in some of the above 

 cases, in which the crossed seeds were the heaviest, as 

 with Sarothanmus and Cyclamen, the crossed capsules 

 contained a larger number of seeds. Whatever may be 

 the explanation of the self-fertilised seeds being often 

 the heaviest, it is remarkable in the case of Brassica 

 Tropaeolum, N emophila, and of the first generation of 

 Ipomoea, that the seedlings raised from them were 

 inferior in height and in other respects to the seed- 

 lings raised from the crossed seeds. This fact shows 

 how superior in constitutional vigour the crossed seed- 

 lings must have been, for it cannot be doubted that 

 heavy and fine seeds tend to yield the finest plants. 

 Mr. Galton has shown that this holds good with Lathyrus 

 )doratus ; an has Mr. A. J. Wilson with the Swedish 



2 A 



