io8 LUCK, OR CUNNING? 



Darwin and Lamarck must be recognised as a co- 

 operator. Unless that increase of a part resulting from 

 extra activity, and that decrease of it resulting from 

 inactivity, are transmissible to descendants, we are 

 vrithout a key to many phenomena of organic evolu- 

 tion. Utterly inadeguate to explain the major part 

 of the facts as is the hypothesis of the inheritance of 

 functionally produced modifications, yet there is a 

 minor part of the facts very extensive though less, 

 which must be ascribed to this cause." (Italics mine.) 



Mr. Spencer does not here say expressly that Eras- 

 mus Darwin and Lamarck considered inheritance of 

 functionally produced modifications to be the sole 

 explanation of the facts of organic life ; modern 

 writers on evolution for the most part avoid saying 

 anything expressly; this nevertheless is the conclu- 

 sion which the reader naturally draws — and was 

 doubtless intended to draw — from Mr. Spencer's 

 words. He gathers that these writers put forward 

 an " utterly inadequate " theory, which cannot for a 

 moment be entertained in the form in which they left 

 it, but which, nevertheless, contains contributions to 

 the formation of a just opinion which of late years 

 have been too much neglected. 



This inference would be, as Mr. Spencer ought to 

 know, a mistaken one. Erasmus Darwin, who was 

 the first to depend mainly on functionally produced 

 modifications, attributes, if not as much importance to 

 variations induced either by what we must call chance, 

 or by causes having no connection with use and dis- 

 use, as Mr. Spencer does, still so nearly as much that 



