THE OBI Gm OF FLOWERS. 



153 



Even in the flowerless plant? we see occasionally 

 some approach to that separate set of organs for 

 reproductive purposes which reaches its fullest 

 development in the colored and scented blossoms 

 of our gardens. Most ferns, as we all know, bear 

 their spores on the under side of every frond, 

 where some of them form the beautiful powder 

 which gives a name and a charm to the gold and 

 silver ferns. But the splendid Osmunda regalis, 

 besides several smaller species, has its seed-ves- 

 sels on an independent stem, thus exhibiting that 

 division of labor among its parts which allows 

 each more efficiently to perform its own special 

 function. And the horse-tails carry this move- 

 ment one step further in advance, having a dis- 

 tinct fruit-bearing growth early in the spring, 

 which is followed by sterile shoots later on in 

 the year. So that through these faint indications 

 we can picture dimly to ourselves the gradual 

 stream of evolution by which the frond- borne 

 spore made its first onward metamorphosis tow- 

 ard the flower-borne seed. 



But such fructiferous heads of embryonic ac- 

 rogens differ widely in the most important par- 

 ticular from true flowers. They do not need fer- 

 tilization. 1 The very essence of the flower con- 

 sists in the fact that its ovule, or embryo seed, 

 must be quickened into fresh life by the contact 

 of pollen, either from the same or another bloa- \ 

 som. All the rest which we ordinarily think of 

 as belonging to the flower — its bright petals, its 

 sweet scent, its store of honey — are merely so 

 many accessories to this central fact. The true 

 flower begins at the point where pollen and 

 ovules first make their appearance. And, in the 

 earliest geological flowering plants, the pollen 

 was apparently wafted to the ovule on the wings 

 of the wind, not on the heads or bodies of in- 

 sects. They belonged to that coniferous family 

 in which the seeds are borne on a scaly head, 

 such as we know so familiarly in the pine and 

 the fir tree : so that their green scales could have 

 formed no exception to the prevailing verdure of 

 a palaeozoic forest. 



" But what advantage did the plant gain from 

 this complicated arrangement of seed-producing 

 organs ? " A not unnatural question to ask, yet 

 a very difficult one to answer. So far, only a 

 speculative explanation of the facts has been at- 

 tempted ; and that speculation is too intricate and 

 too fundamental for any but the trained physiolo- 



1 The obscure phenomena connected with the an- 

 theridia and pistillidia of cryptograms do not interfere 

 with the practical truth of this statement, accepted in 

 a popular sense. 



gist to appreciate. Happily, however, the facts 

 themselves have been placed beyond all doubt by 

 Mr. Darwin's minute observations on cross-fertili- 

 zation. Our great master has shown us that when 

 any organism is the product of interaction be- 

 tween the parts of two other organisms, it pos- 

 sesses a vigor, plasticity, and vital power, far sur- 

 passing that of any similar individual produced by 

 one unaided parent. He has proved incontesta- 

 bly that young plants derived from a self-fertil- 

 ized flower are weaker, poorer, and shabbier, than 

 those derived from the pollen of one flower and 

 the ovule of another. And this general prin- 

 ciple, illustrated on the small scale by Mr. Dar- 

 win's experiments, has been demonstrated on a 

 gigantic scale by Nature herself: for when once 

 the flowering plants were introduced upon the 

 earth by a favorable combination of surrounding 

 circumstances, their superior vitality enabled them 

 in the struggle for existence to live down their 

 flowerless neighbors, and to spread themselves 

 slowly but surely over the whole habitable globe. 

 While the flora of the coal and the earlier forma- 

 tions consists almost entirely of ferns, club-moss- 

 es, and horse-tails, the surface of our existing earth 

 is covered by grasses, herbs, and forest trees ; 

 and only in a few tropical ravines or a stray patch 

 of English warren do we still find the degenerate 

 modern representatives of those Titanic calamites 

 and lycopodites which flourished in the jungles of 

 the Black Country a million asons since. 



We can guess, accordingly, how flowers, in 

 the botanical sense, came first to be developed. 

 Where a chance combination of external agencies 

 occurred to carry certain cast-off reproductive 

 cells of one plant to the most exposed cells of 

 another, there may have resulted such a race of 

 hearty descendants, endowed with a similar ten- 

 dency to produce their like in future, as could 

 compete at an enormous advantage with the sex- 

 less and flowerless plants around. Vague and in- 

 definite as our conception of this process must 

 necessarily be, we can still figure to our imagina- 

 tion enough of its nature to find in it no miracle, 

 but a simple physical fact. The next step in our 

 inquiry must be to account for those bright and 

 conspicuous masses of leaves which the popular 

 eye recognizes as flowers. To do so properly, 

 we must glance first at the few animals and in- 

 sects which peopled the green palaeozoic forests, 

 and whose descendants were to prove the princi- 

 pal agents in developing the blossoms and fruits 

 that we see around us. 



Few if any birds or mammals lived among 

 those rank jungles of more than tropical growth. 



