145 



reproduction, are all effected by single cells, of which the 

 lower plants almost entirely consist ; — that the cell absorbs 

 alimentary matters through the spongioles of the root, and 

 that the fluid received thus undergoes the first steps of the 

 organizing process ; that gum and sugar are converted into 

 the organizable portion of the nutritious sap by the cells of 

 the leaves. The starchy fluid in the grains of corn is ren- 

 dered capable of nutrition to the embryo by the development 

 of successive generation of cells, which exert upon it their 

 peculiar vitalizing influence. Albumen is converted into fibrine 

 by the vital agency of cell life, i. e.^ cells are produced which 

 do not form an integral part of any permanent structure in 

 the plant, but which, after attaining a certain maturity, re- 

 produce themselves and disappear. Hence it may be stated, 

 that all the vegetable productions which are formed in the 

 plant, are efiiected by a series of vital actions through the 

 agency of cells, and even bones and teeth are all formed from 

 metamorphosed cells. Dr. Bennett says, If this be true, 

 " and there can be little doubt, it obliges us to modify our 



notions of organization and life. It compels us to confess 

 " that vegetables and animals are not simple beings, but 

 " composed of a greater or less number of individuals, of 



which thousands may exist in a mass not larger than a grain 

 " of sand, each having a vital centre and separate life, inde- 



pendent of those around it. Each of these individuals or 

 " organized cells should be regarded as a living being, which 



has its particular vital centre of absorption, assimilation, 

 '* and growth, and which continues to vegetate, to increase, 

 " and undergo transformations, as if it were an isolated indi- 

 " vidual. At all events, a knowledge of the existence of the 



cell life of plants will explain several phenomena respecting 

 " the vegetation, growth, and ripening of corn, and may 



hereafter lead to some valuable practical results." 



The Climate^ Elevation^ and Exposure^ are not to be neg- 



