OS BRASSICA OLERACEA. Ghat. IV. 



CHAPTEE IV. 



CRCClFERiE, PArAVERACEiE, RESEDACEiE, ETC. 



Brassea oleracca, crossed and self- fertilised plants Great effect of a 

 cross with a fresh stock on the weight of the offspring Iberis 

 umbellata Papaver vagum Eschscholtzia califomica, seedlings 

 from a cross with a fresh stock not more vigorous, but more 

 fertile than the self-fertilised seedlings Reseda lutea and odorata, 

 many individuals sterile with their own pollen Viola tricolor, 

 wonderful effects of a cross Adonis aestivalis Delphinium consolida 

 Viscaria oculata, crossed plants hardly taller, but more fertile than 

 the self-fertilised Dianthus earyophyllus, crossed and self-fertilised 

 plants compared for four generations Great effects of a cross vr itk 

 a fresh stock Uniform colour of the flowers on the self-fertilised 

 plants Hibiscus africauus. 



VI. CRUCIFEK/E. Brassica oleracea. 

 Var. Cattell's Early Barnes Cabbage. 



The flowers of the common cabbage are adapted, as shown by 

 H. Miiller,* for cross-fertilisation, and should this fail, for self- 

 fertilisation. It is well known that the varieties are crossed so 

 largely by insects, that it is impossible to raise pure kinds in the 

 same garden, if more than one kind is in flower at the same time 

 Cabbages, in one respect, were not well fitted for my experiments, 

 as, after they had formed heads, they were often difficult to mea- 

 sure. The flower-stems also differ much in height ; and a poor 

 plant will sometimes throw up a higher stem than that of a fine 

 plant. In the later experiments, the fully-grown plants were cut 

 down and weighed, and then the immense advantage from a 

 cross became manifest. 



A single plant of the above variety was covered with a net 

 just before flowering, and was crossed with pollen from another 

 plant of the same variety growing close by ; and the seven cap- 

 sules thus produced contained on an average 16 '3 seeds, with a 



* ' Die Befruchtung,' &c. p. 130. 



