THE LIFE VARIES AS THE CORRESPONDENCE. 87 



of each species of organism it might finally be shown, that 

 the same general truth is displayed in the history of mankind : 

 whose advance in civilization has been simultaneous with 

 their advance from the less varied requirements of the torrid 

 zone to the more varied requirements of the temperate zone ; 

 whose chief steps have been made in regions presenting a 

 complicated physical geography ; and who, in the course of 

 their progress, have been adding to their physical environ- 

 ment a social environment that has been growing even more 

 involved. Thus, speaking generally, it is clear that those re- 

 lations in the environment to which relations in the organism 

 must correspond, themselves increase in number and intricacy 

 as the life assumes a higher forui. 



34. To make yet more manifest the fact, that the degree 

 of life varies as the degree of correspondence, I may here 

 point out, that those other distinctions successively noted 

 when contrasting vital changes with rion- vital changes, are 

 all implied in this last distinction their correspondence 

 with external coexistences and sequences. And to this may 

 be added the supplementary fact, that the increasing fulfil- 

 ment of those other distinctions which we found to accompany 

 increasing life, is involved in the increasing fulfilment of this 

 last distinction. To descend to particulars : We saw that 

 living organisms are characterized by successive changes ; 

 and that as the life becomes higher, the successive changes 

 become more numerous. Well, the environment is full of 

 successive changes, both positive and relative ; and the 

 greater the correspondence, the greater the number of suc- 

 cessive changes an organism must display. "We saw that lifo 

 presents simultaneous changes ; and that the more elevated 

 it is, the more marked the multiplicity of them. Well, 

 besides countless phenomena of coexistence in the environ- 

 ment, there are often many changes occurring in it at tho 

 same moment ; and hence increased correspondence with ifc, 

 supposes an increased display of simultaneous changes in the 



