28 THE PAST CONDITION 



ing from the plant the matter for its own support, giving 

 off during its life products which returned immediately 

 to the inorganic world ; and that, eventually, the con- 

 st! I uent materials of the whole structure of both animals 

 and plants were thus returned to their original source : 

 there was a constant passage from one state of existence 

 to :mothcr, and a returning back again. 



Lastly, when we endeavoured to form some notion of 

 the nature of the forces exercised by living beings, we 

 discovered that they if not capable of being subjected 

 to the same minute analysis as the constituents of those 

 beings themselves that they were correlative with that 

 they were the equivalents of the forces of inorganic nature 

 that they were, in the sense in which the term is now 

 used, convertible with them. That was our general result. 



And now, leaving the Present, I must endeavour in the 

 same manner to put before you the facts that are to be 

 discovered in the Past history of the living world, in the 

 past conditions of organic nature. We have, to-night, 

 to deal with the facts of that history a history involving 

 periods of time before which our mere human records sink 

 into utter insignificance a history the variety and physical 

 magnitude of whose events cannot even be foreshadowed 

 by the history of human life and human phenomena a 

 history of the most varied and complex character. 



V"e must deal with the history, then, in the first place, as 



we should deal with all other histories. The historical 



student knows that his first business should be to inquire 



into the validity of his evidence, and the nature of the 



record in which the evidence is contained, that he may 



be able to form a proper estimate of the correctness of 



the conclusions which have been drawn from that evidence. 



So. here, \ve must pass, in the first place, to the consideration 



of a mailer \\liicli may seem foreign to the question under 



discussion. \Ve must dwell upon the nature of the records, 



and tin- credibility of the evidence they contain ; we must 



!<) the completeness or incompleteness of those records 



s, before we turn to that which they contain and 



I. The question of the credibility of the history, 



:y for us, \\ill not require much consideration, for, 



in this liMory, unlike those of human origin, there can be 



no cavilling, no dinVivmvs as to the reality and truth of 



tin- fm-t soi v, hichit is made up ; the facts state themselves, 



and are laid out clearly before us 



