VII. THE LAWS OF ENVIRONMENTAL 

 CHANGE, OR THE "ORDERLY SE- 

 QUENCE OF EXTERNAL NATURE" 



THE DYNAMIC AND PROCESS RELATIONS OF THE ENVIRONMENT 



"Of all the truths relating to phenomena, the most valuable to 

 us are those which relate to the order of succession. On a knowl- 

 edge of these is founded every reasonable anticipation of future 

 facts, and whatever power we possess of influencing those facts 

 to our advantage." JOHN STUART MILL. 



"To study life we must consider three things: first, the or- 

 derly sequence of external nature ; second, the living organism and 

 the changes which take place in it ; and, third, the continuous 

 adjustment between the two sets of phenomena which constitutes 

 life." W. K. BROOKS. 



"The truth, indeed, is, that in physical inquiries, the work of 

 theory and observation must go hand in hand, and ought to be 

 carried on at the same time, more especially if the matter is very 

 complicated, for there the clue of theory is necessary to direct 

 the observer. Though a man may begin to observe without any 

 hypothesis, he cannot continue long without seeing some general 

 conclusion arise ; and to this nascent theory it is his business to 

 attend, because, by seeking either to verify or to disprove it, 

 he is led to new experiments, or new observations. He is led 

 also to the very experiments and observations that are of the 

 greatest importance, namely to those instantice crucis, which are 

 the criteria that naturally present themselves for the trial of 



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