ANIMAL NATURE OF DIATOME^. 497 



of the Zoosperms, of Sphagna, Chares, Marchantiea, 

 Filices, and, lastly, of Fucaceae, prove nothing more than 

 this, that vegetable beings, in certain stages of their 

 development, and in certain conditions, possess a mobility 

 that simulates animal mobility. It is a positive fact, 

 that the complicated animal organisation discovered by 

 Ehrenberg in many of his polygastric Infusoria, cannot 

 be recognised in some that are referred by analogy to the 

 same class ; but it does not at all follow, from this, that 

 we ought to regard these sporidia and the spores of 

 Algae as animals ; for, besides their want of this organisa- 

 tion, they manifest an evidently vegetable nature by their 

 subsequent development. Neither ought we to deny an 

 animal nature to other beings in which this complicated 

 organisation exists. The multiplication by division, or, 

 in other words, temnogenesis, is not, as Ehrenberg 

 believed, exclusively animal. By good right we admit it 

 in vegetables also. But is the organic process by which 

 it is accomplished the same in the two kingdoms? If 

 the character, in its generality, cannot serve for the dis- 

 tinction, it only follows that there is a necessity for further 

 researches in order to discover the peculiarities. 



The Closteria, and Desmidiese, in general are plants, 

 and not animals. In the actual state of science, we are 

 compelled to admit this proposition. The organic struc- 

 ture, the physiological phenomena, the history of their 

 development, the chemicalmaterials they contain, manifest, 

 in these beings, a perfect correspondence with others, 

 which, in every point of view, correspond with the ab- 

 stract idea of a plant. But what they present in common 

 with other beings, evidently animal, is merely an appear- 

 ance, or, at the most, a resemblance, in external form. 

 Ehrenberg was misled by this appearance, and guided 

 by this fallacious similitude, thought that he discovered 

 in the Desmidiese, the same organic peculiarities which 

 proved the animality of other beings. Ought he to have 

 reasoned thus ? However, the most accurate observer, and 

 the man of genius, is liable to error. Nor by this can 



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