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Remarks on the Final Causes of the Sexuality of Plants, with particular reference to Mr. Darwin's Work 'On the Origin of Species by Natural Selection.' By C. J. B. DAUBENY, M.D., LL.D., F.R.S., Professor of Botany in the University of Oxford.

Dr. Daubeny began by pointing out the identity between the two modes by which the multiplication of plants is brought about, the very same properties being imparted to the bud or to the graft, as to the seed produced by the ordinary process of fecundation; and a new individual being in either instance equally produced.

* All communications to the Smithsonian Institution should be addressed to "Professor Henry, Secretary of the Smithsonian Institution, Washington, D.C., U.S.A."

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We are therefore led to speculate as to the final cause of the existence of sexual organs, in plants, as well as in those lower animals which can be propagated by cuttings.

One use, no doubt, may be the dissemination of the species; for many plants, if propagated by buds alone, would be in a manner confined to a single spot. Another secondary use is the production of fruits which afford nourishment to animals. A third may be to minister to the gratification of the senses of man by the beauty of their forms and colours.

But as these ends are only answered in a small proportion of cases, we must seek further for the uses of the organs in question; and hence the author suggested, that they might have been provided, in order to prevent that uniformity in the aspect of Nature which would have prevailed if plants had been multiplied exclusively by buds.

It is well known that a bud is a mere counterpart of the stock from whence it springs, so that we are always sure of obtaining the very same description of fruit by merely grafting the bud or cutting of a pear or apple tree upon another plant of the same species.

On the other hand, the seed never produces an individual exactly like the plant from which it sprung, and hence by the union of the sexes in plants some variation from the primitive type is sure to result.

Dr. Daubeny remarked, that if we adopt in any degree the views of Mr. Darwin with respect to the origin of species by natural selection, the creation of sexual organs in plants might be regarded as intended to promote this specific object. Whilst, however, he gave his assent to the Darwinian hypothesis, as likely to aid us in reducing the number of existing species, he wished not to be considered as advocating it to the extent to which the author seems disposed to carry it. He rather desired to recommend to Naturalists the necessity of further inquiries, in order to fix the limits within which the doctrine proposed by Darwin may assist us in distinguishing varieties from species.

BOTANY.

Dr. DAUBENY invited the Members to visit an experimental garden under his superintendence in the neighbourhood of Oxford, in which he had been carrying on some investigations connected with Agricultural Chemistry, the nature of which he proposed to explain on the spot.

On a Plant Poisoning a Plant. By R. DOWDEN.

On Abnormal Forms of Passiflora cærulea. By Dr. C. DRESSER.

On the Morphological Laws in Plants. By Dr. C. DRESSER.

On the supposed Germination of Mummy Wheat.

By the Rev. Professor HENSLOW, M.A., F.L.S.

The author introduced his observations by reading a letter from Professor Wartmann, of Geneva, who had recently found that seeds might be exposed to a temperature of 198° below zero of Fahrenheit's scale, without losing the power of germination. Professor Henslow had himself exposed seeds to the temperature of boiling water, and they germinated. The question of how long seeds would retain their vitality was one of great interest; and a Committee of this Association had reported on the subject, but they had not succeeded in making seeds grow which had been kept more than two centuries. He then showed that experiments recorded on the growth of mummy wheat were not trustworthy; and especially noticed the case which had been relied on so much, of the growth of mummy wheat by Mr. Tupper from seeds supplied him by Sir Gardner Wilkinson. He alluded to a sample of mummy wheat which he had carefully inspected grain