ADAPTATION i8i 



structure of the mammalian eye, as comparable with the 

 structure of an optical instrument. If the reader will refer 

 back to my quotation of it he will find at least twenty supposi- 

 tions. Granting these, he concludes : " May we not believe 

 that a living optical instrument might thus be formed, as 

 superior to one of glass as the works of the Creator are to 

 those of man ? " ^ 



On the other hand, I would say, recognise the universal 

 pov/er of response in protoplasm to external conditions — in 

 the case of the eye it is light — ^then the human eye could be, 

 and has been, evolved probably from some pigment spot on 

 the skin. 



Since the preceding was written, the second edition of 

 the Text-book of Botany, by Strasburger, Noll, Schenck and 

 Schimper has appeared (1903). 



In the first edition (1898) after describing Darwin's theory, 

 the authors mention some difficulties, such as the one often 

 made that "organs which would be incapable of exercising 

 their functions until in an advanced state of development," etc. 



This paragraph is replaced by another in which they adopt 

 the view of Evolution by direct Adaptation as follows : " It 

 would appear . . . that the starting point for the origin of 

 new species is not afforded by the ' fluctuating variations ' 

 [individual differences] which continually occur, but by 

 more marked variations which have been termed ' Mutations '. 

 [They are here referring to Hugo de Vries' Die Mutations- 

 theorie, 1901.] The tendency is to assume the existence of 

 a development of the organic world due to original innate 

 capabilities of the living substance and not dependent on 

 selection. 



" The origin of the large subdivisions of the animal and 

 vegetable kingdoms, the 'archetypes,' would be due to this sort 

 of Evolution. These archetypes have been, and are still, con- 

 tinually influenced by the environment, and by their reaction 

 to external conditions organisms have become more or less 



^Origin of Species, p. 146. 



