LECT. II.] DEFINITION OF A PLANT. 45 



distinguishing characteristic of plants, cannot be 

 regarded as correct. 



M. Mirbel, in a late work, entitled, Trait 6 

 tfAnatomie et de Physiologic ^gdtales, has given 

 an opinion, which Sir J. E. Smith considers as con- 

 clusive on this subject. He observes, " that plants 

 " have the power of deriving nourishment from in- 

 " organic matter, which is not the case with ani- 

 a mals, who feed on animals and vegetables, and 

 " sometimes on both; but are never nourished on 

 " earths, salts, and airs. So that it should seem 

 " to be the office of vegetable life alone to trans- 

 " form dead matter into organized living bodies*." 

 This remark is, certainly, exceedingly ingenious 

 and plausible; but it contains an assumption 

 which cannot be admitted to the extent required ; 

 for, if by inorganic matter is to be understood 

 simple earths and salts, which do not form parts 

 of decaying organized bodies, the observation is 

 not just ; nor can we allow that airs are taken in 

 as food by plants. What soil can be found com- 



* " C'est la faculte qu'ont les plantes de se nourrir de sub- 

 " stances inorganiques, faculte qui ne paroit pas exister dans 

 " les animaux : ils devorent des substances animales ou vege- 

 " tales, et quelquefois les unes et les autres ; mais jamais, ce 

 " me semble, ils ne se nourissent de terres, de sels, d'air et de 

 " gaz. Ainsi, les vegetaux doivent, pour condition premiere 

 " de leur existence, transformer la matiere brute en matiere 

 " organisec et vivante." Tonne i. p. 19. 



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