sh. iv.] THE LAW OF EVOLUTION. 335 



another occasion — we are now enabled to see how it is that 

 organic bodies can practically solve the dynamic paradox of 

 acquiring a high degree of concentration, even while retain- 

 ing an immense amount of motion. We are prepared to 

 find, under these quite peculiar conditions, the structural 

 rearrangements characteristic of Evolution carried on to a 

 great extent. And we need not be surprised at finding these 

 secondary phenomena here displayed so conspicuously as to 

 obscure the significance of the primary phenomenon, inte- 

 gration. It was, in fact, through the study of organic pheno- 

 mena by physiologists that a formula was first obtained for 

 the most conspicuous features of Evolution ; while the less 

 obtrusive but more essential feature not only remained un- 

 noticed until Mr. Spencer discerned it, but was not ade- 

 quately treated even by him previous to the publication of 

 his rewritten " First Principles," in 1867. I think it there- 

 fore advisable, in dealing with the law as generalized from 

 organic phenomena, to begin by describing these most con- 

 spicuous features. We shall thus obtain a clearer view of 

 the whole subject than we could well obtain in any other 

 way. Having shown that Evolution is always and primarily 

 an integration of matter attended by a dissipation of motion ; 

 and having shown that under certain conditions, most com- 

 pletely realized by organic bodies, certain secondary but 

 equally important phenomena of structural rearrangement 

 may be expected to accompany this fundamental process ; 

 we must next show what these secondary phenomena are. 



The exposition will be rendered clearer by the preliminary 

 explanation of four technical terms, which will continually 

 recur, and which must be thoroughly understood before any 

 further step can be taken toward comprehending the Law of 

 Evolution. These terms are neither obscure in themselves, 

 nor newly coined, but because we shall henceforth employ 

 them in a strict and special sense, they require careful 

 definition. 



