188 HERBERT SPENCER and fullness of life, and has doubtless done so, yet until we come to its highest forms in subjective and finally rational selection, it works not towards an ideal but towards a relative fitness to present conditions. And this may spell degeneration, as in parasites, when an extrinsic standard is used. Tapeworms may be just as fit to survive as golden eagles. Again, the process of elimination does not necessarily mean that the handicapped variants come at once to a violent end, as when rat devours rat, or the cold decimates a flock of birds in a single night; it often simply means that the less fit die before the average time, and are less successful than their neighbours as regards pair- ing and having offspring. Moreover, although the selective process is primarily eliminative or destructive, like thinning turnips or pruning fruit-trees, we can- not separate its positive and negative aspects. That nothing succeeds like success is continually verifiable in nature, the fit variant gets a start just as surely as the unfit variant is handicapped; there is favouring and fostering just because there is sifting and singling. Given variations and given some mode of selection in the manifold struggle for existence, the argument continues, then the result will be in Spencer's phrase " the survival of the fittest.'* And since many varia- tions are transmitted from generation to generation, and may, through the pairing of similar or suitable mates, be gradually increased in amount and stability, the eliminative or selective process works towards the establishment of new adaptations and the origin of new species. Darwin thought chiefly of the struggle between individuals—either between fellows of the same kin function included, must be in some