398 British Association* 



Proceeding s. — S e c t i o n II. 

 Botany, — Darwin's Theory. 



'On the Final Causes of the Sexuality of Plants, with particular 

 Eeference to Mr. Darwin's Work " On the Origin of Species by 

 Natural Selection,"' by Dr. Daubeny. — Dr. Daubeny began by 

 pointing out the identity betwen the two modes by which the 

 multiplication of plants is brought about, the very same proper- 

 ties being impart: d to the bud or t3 the graft as to the seed pro- 

 duced by the ordinary process of fecundation, and a new indivi- 

 dual being in either instance equally produced. We are, there- 

 fore, 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 dissemi- 

 nation 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 the nourish- 

 ment 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 pro- 

 vided, in order to prevent that uniformity in the aspect of Nature, 

 which would have prevailed if plants had been multiphed exclu- 

 sively 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 a 

 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 sprang ; and hence, 

 by the union of the sexes in plants, some variation from the pri- 

 mitive 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 in- 

 quiries, in order to fix the limits within which the doctrine pro- 



