334 ANN-tJAL HEPOBT SMITHSONIAIST IN-STITUTION, 1916. 



This has indeed seriously impaired the mutation theory of De Vries, 

 the fundamental example of the (Enothera lamarcMana, seeming to be 

 not a special type of variation, but an example of complex hybridiza- 

 tion. The authors who have especially studied Mendelian heredity 

 find themselves obliged to attribute all the observed facts to combina- 

 tions of already existing factors, or to the loss of factors, a conception 

 which seems to me a natural consequence of the symbolism adopted, 

 but which hardly satisfies the intelligence. In any case, we do not 

 see in the facts emerging from the study of Mendelism, how evolu- 

 tion, in the sense that morphology suggests, can have come about. 

 And it comes to pass that some of the biologists of greatest authority 

 in the study of Mendelian heredity are led, with regard to evolution, 

 either to more or less complete agnosticism, or to the expression of 

 ideas quite opposed to those of the preceding generation ; ideas which 

 would almost take us back to creationism. 



Lamarckism and Darwinism* are equally affected by these views. 

 The inheritance of acquired characters is condemned and natural 

 selection declared unable to produce a lasting and progressi^'e change 

 in organisms. The facts of adaptation are explained by a previous 

 realization of structures which are found secondarily in harmony with 

 varied surroundings. That is the idea which different biologists 

 have reached and which M. Cuenot in particular has developed sys- 

 tematically.^ 



Two recent and particularly significant examples of these two 

 tendencies are furnished us by W. Bateson and by J. P. Lotzy. In 

 his Problems of Genetics, Bateson declares that we must recognize 

 our almost entire ignorance of the processes of evolution, and in his 

 presidential address at the meeting of the British Association in 

 Australia, in 1914, he goes so far as to express the idea that evolu- 

 tion might be considered as the progressive unrolling of an initial 

 complexity, containing, from the first, within itself, all the scope, the 

 diversity, and all the differentiation now presented by living beings. 

 As Mr. Castle cleverly expressed it, carrying the idea to its logical 

 issue, man might be regarded as a simplified ameba, a conclusion 

 which may well give us pause. Here we clearly recognize, on the 

 other hand, modernized in form, but identical in principle, the con- 

 ception of the " emboitement " of the germs, and of preformation, 

 ideas to which, as I have reminded you, the eighteenth century 

 applied the name evolution. It is a conception diametrically op- 

 posed to that of the transformism of the nineteenth century. 



Mr. Lotzy, struck by the results of the crossing of distinct species 

 of Antirrhinum, has reached in the last three years the conclusion 

 that a species is fixed and that crossing is the only source of produc- 



1 Cuenot, " La Gen6se des esp^ces animales," Paris, Biblioth&que Scientifique Interna- 

 tionale (Alcan), 1911. — " TMorie de la priSadaptation," Sclentia, Tome 16, p. 60, 1914. 



