37 8 THE POPULAR SCIENCE MONTHLY. 



ino- to this view we find an explanation for the actual separation 

 upon different plants of stamens and pistils in dioecious species, 

 in different flowers in monoecious plants, and their practical sepa- 

 ration 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 hav- 

 ing 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 fer- 

 tilization." 



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 com- 

 pound 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 culti- 

 vated 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., pos- 

 sibly at the expense of stamens, as seen in many of the pistil- 

 late sorts. By granting this there is no intention of overlook- 

 ing the long-established tendency in the wild plant to develop 



