LINNEAN SOCIETV OE LONDON. XlX 



numerous cases where the relative proportious of the styles and 

 stamens, or the constant dissimilarity of two sets of flowers, have 

 entered more or less into specific characters will probably ere long 

 be sifted and reduced to their just value, and facts accumulated 

 which may give us some further insight into the laws which 

 govern this curious provision. 



In the case of insects, we listened with great interest, a few 

 meetings since, to a paper of Mr. Wallace's, which appeared to 

 contain new facts and views of considerable importance in the 

 economy of insect life, especially in relation to dimorphism or 

 heteromorphism, although not of the same description as what is 

 so termed in plants. It is impossible, however, to understand 

 correctly discussions of this nature without study, and it would 

 be premature to give any opinion on them till the paper is pub- 

 lished, as I hope it will be by the close of the year. 



I cannot conclude my remarks upon the recent progress of bio- 

 logical science without alluding to the modern discovery of the 

 dynamical theory of heat, or equivalence of heat and force — a won- 

 derful theory, which the lectures of Tyndall have rendered practi- 

 cally clear even to the unscientific mind, but which, nevertheless, 

 it is difficult to follow in all its details without feeling a certain 

 bewilderment of the brain. I may refer to Dr. Carpenter's article 

 " On the Application of the Principle of Conservative Force to 

 Physiology," in the 'Quarterly Journal of Science' for January 

 and April of the present year, for a general review of the influence 

 of this force on vegetable and animal life ; and for a more popular 

 summary, to the graphic sketch of the relation of the sun to life, 

 contained in the closing portion of Prof. Tyndall' s twelfth lec- 

 ture. But in this summary occur the following passages, which, 

 however correct in regard to the great principle they are intended 

 to illustrate, might yet, I think, withoiit explanation, lead the 

 ordinary reader into considerable error with regard to some great 

 biological facts, and upon which therefore, on account of the high 

 standing of the distinguished author, and the general circulation 

 which the work must command, I think it necessary to ofler a few 

 observations. 



" The earth's atmosphere contains carbonic acid, and the earth's 

 surface bears living plants ; the former is the nutriment of the 

 latter. The plant apparently seizes the combined carbon and 

 oxygen, tears them asunder, storing up the carbon, and letting the 

 oxygen go free. By no special force, different in quality from 

 other forces, do plants exercise this power : the real magician is 

 here the sun." (p. 430.) 



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