PRESENT CRISIS IN EVOLUTIONARY THOUGHT 13 



know," it runs, "of the distribution of variability in nature, 

 the scope claimed for natural selection must be greatly re- 

 duced. The doctrine of the survival of the fittest is undenia- 

 ble so long as it is applied to the organism as a whole, but 

 to attempt by this principle to find value in all definiteness 

 of parts and functions, and in the name of science to see fitness 

 everywhere, is mere eighteenth century optimism. Yet it was 

 in its application to the parts, to the details of specific dif- 

 ference, to the spots on the peacock's tail, to the coloring of an 

 orchid flower, and hosts of such examples, that the potency of 

 natural selection was urged with greatest emphasis. Shorn 

 of these pretensions the doctrine of the survival of favored 

 races is a truism, helping scarcely at all to account for the 

 diversity of species. Tolerance plays almost as considerable 

 a part. By these admissions the last shred of that teleological 

 fustian with which Victorian philosophy loved to clothe the 

 theory of evolution is destroyed." {Heredity, "Presidential 

 Address to Brit. Ass'n for Advanc. of Science," Aug. 14, 1914.) 

 Nor is this all. The Darwinian Selection Principle is re- 

 proached with having retarded the progress of science. It is 

 justly accused of having discouraged profound and painstak- 

 ing analysis by putting into currency its shallow and spurious 

 solution of biological problems. "Too often in the past," says 

 Edmund Wilson, "the facile formulas of natural selection have 

 been made use of to carry us lightly over the surface of unsus- 

 pected depths that would have richly repaid serious explora- 

 tion." (Smithson. Inst. Rpt. for 1915, p. 406.) 



In retaliation for the destructive criticism of natural selec- 

 tion, the Neo-Darwinians have proceeded to pulverize the 

 Lamarckian tenet concerning the inheritability of acquired 

 adaptations. Weismann, having laid down his classic dis- 

 tinction between the soma (comprising the vegetative or tissue 

 cells in contact with the environment) and the germ {i.e. the 

 sequestered reproductive cells or gametes, which are sheltered 

 from environmental vicissitudes) , showed that the Lamarckian 

 assumption that a change in the somatic cells (which con- 



