98 HETEROSTYLED DIMORPHIC PLANTS. CHAP. III. 



pollen from the stamens of corresponding height borne 

 by the flowers of the other form, and legitimate fertilisa- 

 tion is thus ensured. 



Thus we can understand the meaning of the torsion 

 of the styles in the long-styled flowers alone^ as well 

 as their divergence in the short-styled flowers. 



One other point is worth notice. In botanical works 

 many flowers are said to be fertilised in the bud. This 

 statement generally rests, as far as I can discover, on 

 the anthers opening in the bud; no evidence being 

 adduced that the stigma is at this period 'mature, or 

 that it is not subsequently acted on by pollen brought 

 from other flowers. In the case of Cephalanthera 

 grandiflora I have shown* that precocious and partial 

 self-fertilisation, with subsequent full fertilisation, is 

 the regular course of events. The belief that the 

 flowers of many plants are fertilised in the bud, that 

 is, are perpetually self-fertilised, is a most effectual bar 

 to understanding their real structure. I am, however, 

 far from wishing to assert that some flowers, during 

 certain seasons, are not fertilised in the bud; for I 

 have reason to believe that this is the case. A good 

 observer,! resting his belief on the usual kind of evi- 

 dence, states that in Linum Austriacum (which is 

 heterostyled, and is considered by Planchon as a variety 

 of L. perenne} the anthers open the evening before 

 the expansion of the flowers, and that the stigmas are 

 then almost always fertilised. Now we know positively 

 that, so far from Linum perenne being fertilised by its 

 own pollen in the bud, its own pollen is as powerless 

 on the stigma as so much inorganic dust. 



Linum flavum. The pistil of the long-styled form 

 of this species is nearly twice as long as that of 



* 'Fertilisation of Orchids,' p.' t' Etudes <=nr la G6ogr. Bot.,' 

 108, 2nd edit. 1877, p. 84. H. Lecoq, 1856, torn. v. p. 325. 



