176 LOBELIA KAMOSA. CHAP. V. 



sown on the opposite sides of four pots ; but tha seedlings were 

 not sufficiently thinned. Only the tallest plant on each side was 

 measured, when fully grown. The measurements are given in 

 the preceding table. In all four pots the crossed plants flowered 

 first. When the seedlings were only about an inch and a half in 

 height both lots were equal. 



The four tallest crossed plants averaged 19 '28, and the four 

 tallest self-fertilised 18 '93 inches in height; or as 100 to 98. 

 So that there was no difference worth speaking of between the 

 two lots in height ; though other great advantages are derived, 

 as we have seen, from cross-fertilisation. From being grown in 

 pots and kept in the greenhouse, none of the plants produced 

 any capsules. 



LOBELIA EAJIOSA.* 

 far. Snow-flake. 



The well-adapted means by which cross-fertilisation is en- 

 sured in this genus have been described by several authors, t 

 The pistil as it slowly increases in length pushes the pollen 

 out of the conjoined anthers, by the aid of a ring of bristles ; the 

 two lobes of the stigma being at this time closed and incapable 

 of fertilisation. The extrusion of the pollen is also aided by 

 insects, which rub against the little bristles that project from 

 the anthers. The pollen thus pushed out is carried by insects 

 to the older flowers, in which the stigma of the now freely 

 projecting pistil is open and ready to be fertilised. I proved 

 the importance of the gaily-coloured corolla, by cutting off the 

 large lower petal of several flowers of Lobelia erinus ; and these 

 flowers were neglected by the hive-bees which were incessantly 

 visiting the other flowers. 



A capsule was obtained by crossing a flower of L. ramose 



* I have adopted the name Mag. of .Nat. Hist.' vol. ii. (4th 



given to this plant in the 'Gar- series) 1868, p. 260. In the allied 



deners' Chronicle,' 1866. Prof. genus Isotoma, the curious spike 



T. Dyer, however, informs me which projects rectangularly from 



that it probably is a white variety the anthers, and which when 



of L. tenuior of R. Brown, from shaken causes the pollen to fall 



W . Australia. on the back of an entering insect, 



t See the works of Hildebrand seems to have been developed 



and Delpino. Mr. Farrer also from a bristle, like one of those 



has given a remarkably clear which spring from the anthers in 



description of the mechanism by some of or all the species of Lo- 



which cross-fertilisation is effected belia, as described by Mr. Farrer. 

 in this genus, in the ' Annals and 



