280 THE STRUCTURE OF FLOWERS. 



Plantarum of Bentham and Hooker, wMle the former has 

 2600 species, the latter has only 1900. Lastly, comparing 

 two orders with regular flowers and two carpels, Boraginece 

 has 1200 species, and Solanece, 1250 ; while the former order 

 never has more than four seeds to a flower, in the latter they 

 are numerous. 



If it were possible, we should procure statistics as to the 

 relative degrees of abundance in individuals of two kinds at 

 any place where they thrive. Casual observations certainly 

 have not led one to notice any such proportional abundance 

 of the many-seeded plants as theoretically ought to exist 

 if all their seeds germinated and grew to maturity ; for I 

 have calculated the number of apparently good seeds in a 

 large plant of Foxglove, and found it was one and a half 

 millions. If we take a typical case, that of Orchids, whose 

 flowers are certainly of those most highly adapted to insect 

 agency, it is now well known that the proportion of seedlings 

 to seed is infinitesimally small. Mr. Fitzgerald speaks of 

 a Dendrohium speciosum, which bore 40,000 flowers open at 

 the same time ; but though the plant was growing in the 

 open air and was exposed to the visits of insects, only one 

 floiver produced a seed pod.* Mr. H. 0. Forbes found the 

 same thing to occur in the terrestrial orchids of Portugal, 

 and the tropical ones of Borneo. f Exactly the same difii- 

 culties are met with in cultivating plants, and especially 

 Orchids (with few exceptions), as Mr. Yeitch has testified. 



Now, when we examine the structure of the essential 

 organs of Orchids microscopically, their degeneracy at once 

 becomes apparent. First, with regard to the pollen. Instead 

 of its being in well-formed distinct grains, each with its 



* Referred to by Mr. Veitch, Report on Orchid Conference, Journ. 

 Roy. Hort. Soc. Bot., vol. vii., p. 47. 



t Journ. Lin. Soc. Bot, vol. xxi., p. 538. 



