OF VITAL MOTION. 27 



originate and operate in the same manner. In the 

 plant, however, the power which enkindles and fosters 

 life proceeds in great part from without ; and it is not 

 until we ascend to animal bodies that the inherent life 

 of the creature assumes any great degree of promi- 

 nence. In the laticiferous movement, which approaches 

 most nearly to the capillary circulation of animals, 

 there is, it is true, the distinct trace of internal power ; 

 and so, also, it may be argued, in the molecular move- 

 ments of "rotation," and in cells which exhibit 

 laminated deposits ; but in all these cases the organic 

 and foreign forces operate in the same manner, and 

 are analogous in character; and it is not necessary to 

 attempt to determine what precise degree of import- 

 ance belongs to either. 



The evidences, moreover, of the operation of any 

 vital principle in the vegetable economy are too ob- 

 scure to allow satisfactory and advantageous inves- 

 tigation, and it is better, therefore, to leave the con- 

 tested topic in complete abeyance until we arrive at 

 the more marked problems of animal life. 



III. OF THE GENEBAL MOVEMENTS OF THE SAP. 



This question is much more simple than it appears 

 to be : and if we take care to suspend the operation 

 of certain unfounded prejudices which appertain to it, 

 we shall find that the general movements of the sap 



