Ueber Germinal-Selection; eine Quelle bestimmt gerichteter Variation

Abstract

THE special purpose of the present treatise, the substance of which was given as an address at the International Congress of Zoologists at Leyden in 1895, is stated by the author to be the rehabilitation of the principle of selection. This principle, though many writers now seek to minimise or to dispense with it, still appears to him to be absolutely necessary for any scientific explanation of the problem of life. The only alternative would be to allow the existence of teleological contrivances, and this in science is inadmissible. The theory of natural selection, says Prof. Weismann, has been rated too highly, and is now suffering the effects of an inevitable reaction. It has not been overrated in the sense of having been credited with too wide a sphere of action, but in the sense that investigators have believed that they understood its whole method of operation, and had a clear conception of all its factors. This, however, is not the case. It has been generally left out of account that besides the individual or personal selection recognised by Darwin, there is a selective process always at work between the various parts of the individual organism (Roux), and even between the ultimate vital units within the germ itself. This conception had already been partly propounded by the author in his Romanes lecture delivered at Oxford in 1894, and in his last rejoinder to Herbert Spencer;¹ it is here stated with greater completeness, and brought into more intimate relation with the doctrine of selection as commonly understood. By its means he claims to have advanced a more satisfactory explanation of the origin of variations and their direction along appropriate lines of development than any as yet proposed.

Ueber Germinal-Selection; eine Quelle bestimmt gerichteter Variation.

Von August Weismann. Pp. xi + 79. (Jena: Gustav Fischer, 1896.)