THE VEGETABLE WORLD. 289 



useless to contest about this or that opinion, about the 

 truth or falsehood of a waking dream, as only too often 

 happensr 



That the germ of organic life came forth upon the 

 earth once, at least, out of the strife of the inorganic 

 elements, admits of no doubt, but there is another 

 question : has this process occurred more than once ? 

 And must it have occurred more frequently ? Since 

 in these matters every one has, and may have, his own 

 proper fantasies, why should not I too have mine ? 

 I hold the assumption of repeated creation, of a totally 

 new origination of vegetable germs, out of unorganized or 

 even inorganic matters, to be superfluous, and therefore 

 not to be admitted, and this opinion I found on the con- 

 sequences of the following considerations on the gradual 

 development of the Vegetable world. The simplest element 

 of the whole vegetable world, is the cell,* a very simply con- 

 structed organism, the origin of which out of the peculiar 

 association of carbonic acid and water, on the one hand, 

 into gum or vegetable jelly, and of carbonic acid and 

 ammonia on the other hand into protoplasm or albumen, is 

 not so very widely removed from a possible explanation, 

 as the sudden origin of a vegetable germ with perfect 

 definite power of development into a peculiar species of 

 plant. That the cell can vegetate as an independant plant, 

 we know from the vegetable Creation at present surrounding 

 us, since many of the simplest plants, especially the Water- 

 plants, consist of a single cell, and are only distinguished 

 from one another by the varying forms. The principal 

 causes producing a luxuriant and varied world of forms in 

 the tropics, are moisture and warmth, the causes of their 



* See the Second, Third and Fourth Lectures. 



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