6 PREFACE. 



proclaim a definite fact. The statement is fully as 

 defensible, from the logical standpoint, as the com- 

 moner phrase that like produces like is. The object 

 of my phrase is to oppose the notion that the forms 

 of life originally possessed hereditary power, or that 

 it was a part of their constitution that Uke should 

 rigidly produce like, and that all variation must, there- 

 fore, be attributed to definite agencies. My own con- 

 ception is that the original forms of life had no cor- 

 poreal characters (using the word character in its tech- 

 nical or natural history sense), and therefore needed 

 only powers of propagation, not of heredity. As 

 the characters arose from the normal variations be- 

 cause of the necessities of environment, so the heredi- 

 tary power arose at the same time. In other words, 

 the constant reproducing of a given variation by 

 recurring similar environments developed a tendency 

 to its perpetuation. The evolution of the organic 

 creation seems to me to have been a constant pro- 

 cess of suppression and elimination of miscellaneous 

 or indefinite variations, resulting in the perpetuation 

 of certain type stems and the obliteration of the in- 

 termediates ; and early in the process the normal 

 plasticity of the life - plasma must have been the 

 source of some of this variation, and it is not im- 

 probable that this type of plastic or fortuitous varia- 

 tion is not yet wholly eliminated from the vegetable 

 kingdom. Or, to state the matter in another form, I 

 conceive the organic creation to have started out with 



