OF PLANTS. 65 



by the new discoveries of science, which uses only its .senses, 

 and showed us that all these visionary comparisons with 

 the totally differently organized animals, are devoid of the 

 smallest foundation. It was my lot, in the share I have 

 taken in the advancement of Botany, to bring this result 

 to light. 



In order to sketch briefly the actual processes of the 

 multiplication of vegetables, I must recall to recollection 

 some points stated in a former lecture. I observed there, 

 that among its other characters, the individual vegetable- 

 cell is endowed with the power of forming new cells in 

 its interior, and thus, as it were, of propagating itself. 

 Now the newly-formed cells have also this peculiarity, they 

 grow and arrange themselves conformably to the cell in 

 which they originate. Thus is the power given to all 

 plants, to develop new plants out of any of their cells, 

 when these come to be placed in favourable circumstances, 

 and by this power is explained the facility with which 

 almost all plants may be multiplied. 



We can, however, distinguish several very different 

 states, according to the difference of the conditions under 

 which Nature renders possible the development of the single 

 cell into a new plant. 



1. In the cells of the plant in general, as I have ex- 

 pressed the law, it very seldom occurs, because it is only 

 in rare cases that the necessary conjunction of all the 

 favouring conditions is brought about. Nevertheless, there 

 are actually some such striking instances of the kind, where 

 leaves of a plant lying on the ground, and even in a her- 

 barium, have suddenly become covered with buds, that is 

 to say the foundations of new plants, so that we cannot 

 doubt the validity of the law. 



2. Instances of a somewhat more limited application of 



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