566 



Miscellaneous. 



which possesses a composition either similar to, or identical with, 

 theirs — as in such a case the assimilation could take place without 

 the decomposition of carbonic acid by the leaves." This is mere ficr 

 tion ; it has no application to parasitical plants. Of equal value is 

 what he says, p. 115 : — " Leaves serve to produce starch, woody 

 fibre, and sugar ; if we therefore bring these matters (starch, woody 

 fibre, and sugar) into plants, by means of their roots, the vital functions 

 of the leaves are disturbed, &c." Now woody fibre is the most in- 

 soluble vegetable matter which we know. It is incomprehensible how 

 such a substance could be conducted by the way of the leaves to the 

 trunk of a tree to serve there for the formation of annual rings. 

 Starch occurs in plants only in the shape of grains, and therefore it 

 likewise cannot be introduced into the trunk and bark by the leaves. 

 As for sugar, it has been proved by the experiments of Saussure and 

 Davy, that plants thrive exceedingly in dissolved gum and sugar, if 

 the solution is not so concentrated as to render endosmose, and 

 consequently nutrition, impracticable. But Dr. Liebig possesses 

 great talents in the way of omitting facts which do not suit his 

 theory ; and instead of confessing that there are many things he does 

 not know, he prefers saying that all those things which he is unable 

 to explain, do not exist. Thus we find (p. 116) the following pro- 

 position : — " Each grain of wheat contains within itself the matter 

 which produces its germ and root-fibres (namely, starch and gluten) ; 

 and we must suppose that these two substances are found there exactly 

 in the proportion necessary for the development of those organs. 

 But the two matters are completely consumed in the formation of 

 the first part of the roots and leaves, and a surplus of either could in 

 no way contribute to the formation of leaves, without a portion of the 

 other matter exactly corresponding to it in quantity." This sounds 

 well, and seems to be the dictum of a great genius ; but, unfortu- 

 nately, it is mere romance, and is contradicted by well-known facts. 

 The proportion of gluten and starch contained in wheat varies greatly 

 — the first between 7"0 and 35-0, and the second between 70-0 and 

 40.0. Can we assert that 7.70 and 35.40 form two proportions, 

 exactly corresponding to one another ? And yet the kinds of corn, 

 thus differently constituted, are equally capable of attaining complete 

 development. 



