256 THE REIGN OF LAW. 



profound ignorance of the cause or origin of varie- 

 ties, yet groups together a great class of facts as 

 connected by a tie which he calls the " Correla- 

 tion of Growth." Now what is this law — this 

 observed Order of facts ? It is that variation in 

 one part of an organism is, as a rule, accom- 

 panied with corresponding variations in other 

 parts, and especially in those parts which are 

 " homologous," that is to say, which occupy the 

 same relative place in the general Plan. 



This, however, is but a very imperfect defini- 

 tion of the vast Order of mysterious facts which are 

 covered by the words " Correlation of Growth." 

 The fundamental idea which these words express 

 is an Idea of wider and deeper significance in 

 Nature, than Mr Darwin seems to have perceived. 

 There is a co-relation between all natural organic 

 growths : that is to say, that any variation of form 

 in a single part has a constant relation to other 

 variations of form in some other part or parts of 

 the same organism. But "relation" is a vague 

 word. There are many kinds of " relation" — there 

 are indeed an infinite variety of kinds. What is 

 the kind of relation that we detect in Correlated 



