Evolution of Veyetal Life. 119 



the formation of crystals, and which is shown ns in tran- 

 scenclently lovely forms in the frost-work upon our win- 

 dows upon a winter morning. 



It is a most interesting question whether the forces which 

 produce organic life differ from those so-called physical 

 forces with which we are familiar in other phenomena. It 

 is clear that all the complicated processes which we call 

 " vital " in ourselves and other higher organisms, are invari- 

 ably found in the closest and most intimate relations, ap- 

 parently of effect and cause, with light, heat, electricity, 

 etc. Modern science has shown these forces to be equiva- 

 lent, correlative and interconvertible, and it would seem an 

 excess of stupidity did we not mentally connect the elab- 

 orate operations which we know with the simpler ones 

 which preceded them, as alike in nature and origin. How- 

 ever we may define it, we are certainly, at present, forced 

 to recognize a distinction between that which we say has 

 life, and that which we say is without life. But this dis- 

 tinction, this parting of the ways, finds us upon a narrow 

 edge. On the side of life, we have an unorganized albu- 

 minous substance without definite size, or form, or bounda- 

 ries, — simply homogeneous matter of intimately united car- 

 bon, hydrogen, oxygen and nitrogen. I should note here 

 that Huxley remarks : " It may be safely said of all those 

 living things which are large enough to enable us to trust 

 the evidence of microscopes, that they are heterogeneous 

 optically, and that their different parts, and especially the 

 surface-layer, as contrasted with the interior, differ phys- 

 ically and chemically." He does not, however, mean by 

 this that the difference extends so far as to constitute or- 

 gans. 



How the differentiation between the living and the not- 

 living took place, who shall say ? All that we know at 

 present is, that it did take place, or that at some time it 

 was, and that among the qualities of which so-called organ- 

 ic matter was then possessed, or which at least it has al- 

 ways exhibited since it has been observed by men, were the 

 capacity for change, and the power of transforming inor- 

 ganic into organic matter. 



Protoplasm in masses, as discovered at the bottom of the 

 sea by the Challenger expedition, was described by Huxley 

 under the name of Bathybius. Of the same composition 

 we find perhaps the lowest forms of individual life, in what 



