MODERNBIOLOGY 5 69 



of this assertion he cites a number of experiments, which, however, 

 have been interpreted differently by modern heredity-research, such as, for 

 instance, Kammerer's experiments with colour changes in the salamander, 

 and Tower's experiments in connexion with the evolution of the beetle. If 

 Hertwig's views on this point approach those of Lamarck, he refuses all 

 the more definitely to have anything to do with Darwin's theory of selection. 

 He brings out the latter's weaknesses in a strong light; he especially points 

 out how much of the theory is borrowed from human conditions and is, 

 moreover, utterly misinterpreted. The breeder who selects suitable variations 

 creates nothing new thereby, but only chooses what suits him, and this pro- 

 cedure has no counterpart in nature — the struggle for existence does not 

 destroy creatures; the masses that die do so from quite different causes. To 

 declare that selection favours certain variations postulates mere chance as 

 an operative cause, but chance is no natural-scientific explanation. And he 

 views with equal disfavour the above-mentioned theory of the struggle of 

 the parts within the organism; this, too, is found to rest upon utterly false 

 conclusions. 



Once again Oscar Hertwig attacks the theory of the struggle for exist- 

 ence and natural selection, in his polemical paper Zur Abwehr des ethischen, 

 des so'^ialen, des politischen Danvinismus, wherein the old student of evolu- 

 tion sharply criticizes the outgrowths that Darwinism had induced in the 

 sphere of social life. The fact is that a number of writers, partly biolo- 

 gists with a deficient social grounding, partly newspaper-men and political 

 authors of various kinds, had made use of the theory of the struggle for 

 existence and of selection to proclaim a new social theory, on the one hand 

 rejecting activities based on Christian charity and strivings after social 

 equality, and on the other hand extolling war, social want, and ruthless 

 competition as phenomena destined to thin out the weaker and less hardy 

 human beings, and thereby to further human progress. Against these asser- 

 tions Hertwig maintains that natural phenomena cannot be made the stand- 

 ards of human culture; justice and morality have their origin exclusively 

 in human community life; in nature no such principles exist; the beast of 

 prey that tears its victim to pieces acts neither justly nor unjustly, but ac- 

 cording to its nature. To make a merciless struggle for existence the basis 

 of social life would therefore be equivalent to destroying all that the cul- 

 tural efforts of the past have built up. War and economic misery are of no 

 constructive value; on the contrary they ruthlessly destroy both the capable 

 and the incapable. Thus in the very bitterest days of the Great War Hertwig 

 dares to hope for a peaceful settlement between the nations. That, however, 

 he did not live to see; when he died, in i9xx, the unhappy consequences of 

 the war — unhappy for the whole of humanity and most of all for his own 

 fatherland — had been brought out in all their frightful clearness, and his 



