100 LIFE AND ORGANISATION. 



POSTSCRIPT. 



THE foregoing article was published a year before the 

 appearance of Mr. Darwin's remarkable work on the ( Origin 

 of Species.' Whatever be thought of some of the conclusions 

 at which Mr. Darwin has arrived, the value of his work as a 

 contribution to the Natural History sciences, and as a guide 

 to their future successful pursuit, cannot be too highly es- 

 timated. Nor is it possible to speak too strongly of the 

 candid spirit manifest throughout this volume ; leading its 

 author to anticipate objections and acknowledge all diffi- 

 culties ; and to state, even perhaps beyond his own belief in 

 them, the conclusions to which his doctrine might be liable, 

 if carried to its extreme inferences. 



Thinking it well that the argument on the other side 

 should be fully and fairly weighed, I have made only a few 

 very slight alterations in the article now reprinted; one 

 of these referring to the changes in the animal world due 

 to the principle of natural selection, operating amidst the 

 general struggle for existence. This principle, which Mr. 

 Darwin has so largely and effectively used in his researches, 

 may be considered in great degree a new path of enquiry ; and 

 one which steadily pursued by exact and patient observation, 

 cannot fail of conducting to important results. It is certain 

 that at some future time a revision and reform will be 

 required of all existing catalogues of genera and species. 

 How far the needful curtailment may carry us is yet doubt- 

 ful ; but there is reason to presume that it will stop very 

 far short of anything like unity of origin, even with unli- 

 mited concession of time for the process and progress of 

 change. An original act of creation, in time and under 



