I cannot enter here into the whole subject of Darwinian criticism.[145] Our aims are of a positive character, they desiderate construction and only use destruction where it is not to be avoided. So I shall only mention that dogmatic Darwinism has been found to be unable to explain every kind of mutual adaptations, *e.g.* those existing between plants and insects; that it can never account for the origin of those properties that are indifferent to the life of their bearer, being mere features of organisation as an arrangement of parts; that it fails in the face of all portions of organisation which are composed of many different parts--like the eye--and nevertheless are functional units in any passive or active way; and that, last not least, it has been found to be quite inadequate to explain the first origin of all newly formed constituents of organisation even if they are not indifferent: for how could any rudiment of an organ, which is not functioning at all, not only be useful to its bearer, but be useful in such a degree as to decide about life or death? [145] See Wigand, *Der Darwinismus und die Naturforschung Newton’s und Cuvier’s*, Braunschweig, 1874-7; Nägeli, *Mechanisch-physiologische Theorie der Abstammungslehre*, München, 1884; G. Wolff, *Beiträge zur Kritik der Darwin’schen Lehre*, 2nd ed. Leipzig, 1898; etc. It is only for one special feature that I should like to show, by a more full analysis, that dogmatic Darwinism does not satisfy the requirements of the case. The special strength of Darwinism is said to lie in its explaining everything that is useful in and for organisms; the competitive factor it introduces does indeed seem to secure at least a relative sort of adaptedness between the organism and its needs. But in spite of that, we shall now see that Darwinism fails absolutely to explain those most intimate organic phenomena which may be said to be the most useful of all. Darwinism in its dogmatic form is not able to explain the origin of any sort of organic restitution; it is altogether impossible to account for the restitutive power of organisms by the simple means of fluctuating variation and natural selection in the struggle for existence. Here we have the logical *experimentum crucis* of Darwinism.