276 THE REIGN OF LAW. 



vibrations, beyond which, in both directions it 

 ceases to be of use." These are indeed wonderful 

 Correlations which reveal to us fittings and ad- 

 justments of which we had no previous concep- 

 tion : but they give us no glimmering even of 

 knowledge as to the physical causes which have 

 " attuned " a material organ so as to catch certain 

 ethereal pulsations in the external world, and to 

 make these the means of conveying to Man's In- 

 telligence the enjoyment and the power of sight. 



It will be seen, then, that when Mr Darwin 

 speaks of the Law of Correlation of Growth as 

 a Law which determines variation in organic 

 growths, he is really presenting to us under one 

 phrase two separate ideas which are radically dis- 

 tinct. One is the idea of different growths in the 

 same organism, corresponding with each other in 

 respect to arrangement, — or in respect to texture, 

 or in respect to form, — or to some other point of 

 comparison. The other idea is that these growths 

 (each and all) correspond with the conditions of 

 external Nature in such a way as to fit them for 

 the discharge of Function with some new adapta- 

 tion, and consequently with some new advantage. 



