S52 WEIGHT AND GERMINATION OP Chap. IX. 



above given cases, in which the flowers were artificially 

 fertilised with their own pollen. 



Considering the facts now adduced, including the 

 appearance of those varieties which are more fertile 

 and taller than their parents and than the intercrossed 

 plants of the corresponding generation, it is difficult 

 to avoid the suspicion that self-fertilisation is in some 

 respects advantageous; though if this be really the 

 case,* any such advantage is as a rule quite insignifi- 

 cant compared with that from a cross with a distinct 

 plant, and especially with one of a fresh stock. Should 

 this suspicion be hereafter verified, it would throw 

 light, as we shall see in the next chapter, on the exist- 

 ence of plants bearing small and inconspicuous flowers 

 which are rarely visited by insects, and therefore are 

 rarely intercrossed. 



Belative Weight and Period of Germination of Seeds 

 from crossed and self-fertilised Flowers. An equal 

 number of seeds from flowers fertilised with pollen from 

 another plant, and from flowers fertilised with their own 

 pollen, were weighed, but only in sixteen cases. Their 

 relative weights are given in the following list ; that 

 of the seeds from the crossed flowers being taken as 100. 



Ipomoea purpurea (parent plants) as 100 to 127 



(third generation) 87 



Salvia coccinea 100 



Brassica oleracea 103 



Iberis umbellata (second generation) 136 



Delphinium consolida 45 



Hibiscus africanus 105 



Tropseolum minus 115 



Lathyrus odoratus (about) 100 



Sarothamnus scoparius 88 



* M. Errara, who intends pub- another newer. I hope that his 



ishing on the present subject, view may hereafter be proved 



has been so kind as to send me correct, as the subject of cross 



his MS. to read. He is convinced and self-fertilisation would be 



that self- fertilisation is never thus much simplified, 

 wore beneficial than a oross with 



