complicated than in any so far noted. Darwin’s book, “On the Various Contrivances by Which British and Foreign Orchids Are Fertilized by Insects,” reads like a fairy tale. Yet it is the result of years of patient observation by incomparably the greatest naturalist of recent times. To it the reader must go for the details of a drama of absorbing interest, but too long to sketch even briefly here. Perhaps one illustration may be mentioned of how far the principle of cross-fertilization has been carried, and to the deadly effects of its failure in at least one case. In a certain orchid from Brazil, known as butterfly orchid, the pollen is nearly always carried out of the flower by an insect visitor, but, if by mischance it is not, and falls on the stigma, not only does it fail to fertilize the ovules, but it kills the pistil forthwith. There may be a few other cases of such drastic results of self-fertilization, but in any case, and disregarding these apparently suicidal fanatics, cross-fertilization is so very nearly universal that nature must find it of enormous advantage. Only in this way is it possible to explain the intricate adjustments of insects and flowers, which work together in such wonderful harmony that cross-fertilization hardly ever fails in those flowers where it appears to be necessary.
It must have struck many thoughtful readers to ask a rather obvious question at this point. Why, if untold millions of insects are constantly flitting from flower to flower, does not the pollen get mixed, as it is quite certain that they will not fly from a