ENVIRONMENT AND EVOLUTION KROPOTKIN. 425 



inherited more or less, then they are sifted by selection, and kept by it within 

 definite lines of development. 1 



Wettstein, who has been experimenting for years upon the modifi- 

 cation of plants by exterior agencies, openly accepts the hereditary 

 transmission of acquired characters in his Handbook of Systematical 

 Botany. He writes: 



In the immense majority of eases adaptive ebaracters are originated by the 

 so-called " direct adaptation " ; in other words, we must recognize in the plant 

 the faculty of adapting itself directly to the prevailing conditions of life and 

 inheriting these acquired adaptation characters. 2 



J. P. Lotsy, the author of a well-known elaborate work on the 

 theories of descent, comes to the conclusion that — 



unless we accept a vis vitalis (a life force) which, after all, would explain 

 nothing, it is impossible to find another reason for the origin of variations but 

 the influence of the external conditions on the substance of the protoplasm, and 

 without an inheritance of the acquired variation, or character, there is no 

 reason for its being fixed. If one absolutely denies the possibility of biometa- 

 morphoses (variations due to environment) being inherited, this means to 

 deny evolution itself. 8 



D. T. MacDougal, after having analyzed ths work of Buchanan, 

 Gages, Klebs, Zederbaum, and de Vries, finds that their discoveries, 

 coupled with his own and other botanists' work at the Desert Bo- 

 tanical Laboratory in the United States and elsewhere, enforce upon 

 us the conclusion that structural changes and implied functional 

 accommodations are without doubt direct somatic responses, which 

 became fixed and permanent in consequence of their annual repeti- 

 tion through the centuries. 4 W. Johannsen, whose main work, Ele- 

 ments of the Exact Science of Heredity, 5 is held in high esteem by 

 biologists of all schools, comes, in one of his latest writings, to the 

 conclusion that without inherited variations " selection would have 

 no hereditary influence." 6 And so on. 



VIII. 



The idea of natural selection apparently did not occur to Lamarck, 

 although several passages in his works suggest that he had noticed 

 the struggle for existence. As to the modern Lamarckians, while 

 nearly all of them indicate the limitations of natural selection, they 



1 M. Standfuss, " Zur Frage der Gestaltung und Vererbung," lecture before the Zurich 

 Naturalists' Society, in January, 1902. Zurich, 1905 (separate reprint). 



2 Handbuch der systematischen Botanik, Vienna, 1901 seq. I quote from Adolph 

 Wagner's Geschichte des Lamarckismus, Stuttgart, 1909, p. 215. 



3 Vorlesungen iiber Descendenztheorien, vol. ii, Jena, 1908. 



4 " The Inheritance of Habitat Effects in Plants," in Plant World, xiv, 1911 ; analyzed 

 in Botanisches Centralblatt, Bd. cxxii, 1913, p. 134. 



5 Elemente der Exakten Erblichkeitslehre, Jena, 1909, pp. 308, 449, etc. 



6 " The Genotype Conception of Heredity " in American Naturalist, xlv, 1911, quoted 

 by Semon in Verhandlungen des Naturforschers-Verein in Briinn, vol. lxix. 



