Miscellaneous. 7 1 A Study of the Hydranciea in relation to Cross-F<. rtiJ ization. By Thomas Meehan. That many flowers are arranged for cross-fertilization needs no argument to sustain it, nor is it less certain that some flowers can only bo fertilized through the aid of wind or insects. Sprengcl, it is well known, in the early part of the present century, placed this beyond doubt. The great question is not, do plants generally cross-fertilize ? but why do they do it ? Mr. Darwin's great work in this connexion has been to prove that plants abhor in-and-in breeding, that the struggle for life is necessarily the chief object of existence, and that cross-fertilization tends to make the race stronger and better fitted to engage in this struggle than close breeding would do. The results of many of Mr. Darwin's experiments sustain his views, as do those of many others ; but to my mind just as large a number do not sustain them. Mr. Darwin himself has candidly stated that continuous self-fertilization docs not in the least impair the fertility of the race. Mere negative vigour is the leading advantage he finds in crossed plants. (Cross and Self-fertilization, Chap. IX. p. 327.) It is not my object now to controvert the views of Mr. Darwin, or of his numerous followers. My view of one object of nature in cross-fertilization is to aid in production of variety. I have shown ever since discussion grew warm on these subjects, that variation is essential to the present order of things, — that nature, to be consis-tent with herself, must provide for variations if for no other purpose than to make variety. I now propose to show, by some studies in Hydrangea, that the variations in the species are of the most con-tradictory character taken from the standjwint of benefits in the struggle for life, while they are entirely consistent with my view of variation for variety's sake. Our garden Hydranr/ea, from Japan {Hydrangea hortensis*), has the ray-florets sterile, or rather it is tho lateral florets of the compound cyme that give the enlarged sepals, and fail to perfect the gynoscium. The terminal florets are fertile. In H. quercifolia all the lateral florets are fertile, and it is only the terminal one that has petaloid sepals and is barren. Will any one assert that these exactly opposite conditions can have any bearing whatever as aids in a struggle for life ? Suppose we say that the attractive sepals are given to these species for the purpose of attract-ing insects, and thus aiding cross-fertdization. With this view we examine the American species //. arhorescens, and we find barely an attempt to make tliese enlarged petaloid sepals. There are email ones on a few terminals and this is all. It has made out certainly as well in the great struggle as either of its two brethren. But is it a fact that the showy sepals are given to the plant to attract * Franchet and Savatier insist that Smith's name of //. hortensis has priority over II. Ilortensia.
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