Page:Popular Science Monthly Volume 37.djvu/392

378 to this view we find an explanation for the actual separation upon different plants of stamens and pistils in diœcious species, in different flowers in monœcious plants, and their practical separation in all cases when the stamens and pistils in perfect flowers mature at different times (dicogamy). Again, there is a long list of plants in which wide fertilization is secured by one flower having long stamens and short pistils, and another of the same species with short stamens and long pistils (dimorphism). Aside from all these well-defined plans for crossing, there are hundreds of others none the less obscure and often vastly more ingenious—plans so well worked out that the plant will fail to produce seeds unless a particular kind of insect visits it. All such species are constantly striving to arrive at a perfect adaptation between the flower and the peculiarities of its insect attendant. In short, the plan for wide fertilization is so thoroughly apparent along the many lines, that Darwin expressed the condition in the following concise and striking terms: "Nature abhors continual close fertilization."

The structure and form of the essential organs, like those of the floral envelopes, have come to their present condition through the prolonged interaction of plant and insect. Now, at the outset plants cultivated for their flowers were those already showy—that is, those in which the floral envelopes were conspicuous, fantastic, or sweet-scented. Let us bear in mind that these showy wild flowers became so in competition with hundreds of other species, and underwent all the expense of floral display for purely selfish ends. Each species worked out the problem of reproduction in its own way; and it is safe to assert that it became as much a part of the life of a wild rose to develop bright petals as to form compound leaves with large stipules.

In the historic development of such flowers it may be assumed that the essential organs came first, and the surrounding parts appeared and were preserved as they were found of service to the plant. As time went on, additional stamens and pistils may have been added, until the most economical number of parts was reached—if it has been reached. The number varies in many of the wild species to-day, and especially in those prominent in the flower-garden.

It is only fair to hold the successful floriculturist responsible for much of the seemingly stable increase of display in cultivated plants over their wild forms. This is the same credit that is freely given to the horticulturist who increases the size, for example, of the strawberry, by crossing, selection, etc., possibly at the expense of stamens, as seen in many of the pistillate sorts. By granting this there is no intention of overlooking the long-established tendency in the wild plant to develop