THE LOGIC OF CLASSIFICATION. 253 arranging plants and animals in the vast graded system of the Natural History sciences, we aim as far as may be at reproducing Nature, and our divisions can hardly be more sharply cut than obtains in reality. Nevertheless, it must never be forgotten that, in each and all of these cases, there is a plan ; and the very fact of a plan implies a logical procedure. And, as the ruling trait is fixity and number of correlated properties, rigorous adherence to this principle will keep us as near to the requirements of logic as the materials admit of. v. A word, finally, may be due on the bearing of Evolution on Natural History Classification. Many evolutionists affect to despise Classification, and, as far as one can judge, seem to regard it as inconsistent with, or actually opposed to, their pregnant theory. Nothing, surely, is more unwarranted. It may safely enough be asserted that, had it not been for the existence of a highly developed scheme of biological classing, Evolution would still have been a thing to search for. And with equal confidence may it be asserted that, the more thoroughly Evolution is worked and the further it progresses, the greater is the help it will render towards the perfecting, not the destruction, of the Natural system. What Evolution does is to throw new light upon biological facts ; and, in throwing new light upon them, it is better fitted than anything else to bring out affinities and resemblances among living beings. Now, as it is on affinities and fixed resemblances that Natural classifica- tion reposes, much may be hoped, and nothing need be feared, from the advance of this great fruit-bearing conception.
