that even an approximate consensus of opinion among biologists will ever issue from such general discussion of the "natural selection factor" as has been carried on during the last half century? I do not think so. The most that can be said for such views is that they stimulate research. But there is an aphorism in hygiene about over stimulation that ought not to be forgotten even in science, when stimulants are advocated.
What more prophetic utterance of Darwin's can be found than that made to Wallace after he had thought over natural selection for twenty years? "My work," he said, "will not fix or settle anything."
Another important matter that Darwin never laid hold upon with sufficient grip is the great significance of struggle aside from its role in species production. The numberless things that struggle may accomplish short of killing somebody, did not greatly attract his attention. From his standpoint struggle short of life and death struggle seems not to have counted for much. So in his writings struggle almost always appears as "struggle for existence."
Nature is exactly a vast system of parts, each part having a nature of its own, but at the same time being dependent upon innumerable other parts.
"Natural selection" (the expression has for the most part been restricted to the living world, but there is no essential reason why it should be. It would be quite as explanatory of the process of origination, applied in the inorganic, as in the organic, realm) is that complex of operations by which natural bodies get so located that the capabilities of portions of nature for doing their part toward the sustentation of other portions are utilized to the best advantage. Otherwise stated, it is the method by which organisms become arranged in nature according to their special needs and merits. In this operation, inconvenience, injury and destruction often result. But such results are among others, rather than the end and aim, the total result of the process. In many cases, though by no means in all, it must play a large part in determining the characteristics, especially in late life, of individual organisms. In a word, natural selection is probably one vera causa in species formation. In what instances it has been thus influential, and how far this influence has gone, are matters to be ascertained, as far as possible, in each particular case. If Greenland has the wherewithal to support men, in however meager and cheerless a way, it is at least as reasonable to conceive Mother Nature (if one is to personify nature) as congratulating herself that she has some men able to accept such bounty and like it, as to conceive her as fiendishly gloating, or filled with impotent grief, as the case may be, over having crowded a few of her mortal beings off into so hard a quarter. Darwin did not view the process in this light very much
