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Rh as the attempt to base the eternal truth of religion on what may eventually prove to be a transient phase of scientific belief.

With regard to evolution, however, we are dealing with what may fairly claim to be an established doctrine. Certainly it is not too much to say that in the scientific world it has won its way to security, and has brought over to its side the vast majority of those who have a right to give an opinion on the scientific question. In saying this, however, we do not mean that evolution is stereotyped in the form in which Darwin gave it to the world. No one would more indignantly resent such a possibility than Darwin himself. And it is remarkable that the year which told us the story of Darwin's work and life, found us face to face with two attempts to carry out the doctrine of evolution in different, and as it seems, mutually inconsistent lines. In the July number of the "Journal of the Linnæan Society," 1886, Mr. Romanes propounded a theory—perhaps we should more properly say suggested for consideration a theory—to which he gave the name of physiological selection. Last year, thanks to two excellent articles in "Nature," by Prof. Moseley, and a paper at the British Association on "Polar Globules," we were introduced to Prof. Weismann's "germ-plasma" doctrine.

What is commonly known as Darwinism includes in it two elements which are by no means necessarily connected—the one the Lamarckian theory of descent, the other the more strictly Darwinian theory of natural selection. We had got so accustomed to being told that the experience of one generation became the instinct of the next, and that the transmission of acquired habits was one of the most important as well as the most obvious factors in the variation in species, that it is somewhat startling to be told now that there is no verified case of the transmission of acquired characters, and that the Lamarckian doctrine of descent was never essential to Darwinism, though it existed as a survival in it. Yet this, in short, is Prof. Weismann's view, and it was received with general favor at the Manchester meeting of the British Association. It would seem to those who speak without special knowledge that the two views advocated respectively by Mr. Romanes and Prof. Weismann are mutually incompatible, and that the latter view if adopted would be fatal to some of the most cherished theories of Herbert Spencer. According to Mr. Romanes, "natural selection is not a theory of the origin of species." According to Prof. Weismann, natural selection is the main cause of such variation. Mr. Romanes talks of the "swamping effects of intercrossing," while Prof. Weismann sees in every case of sexual reproduction a multiplication of the possibilities of adaptation to an unfavorable