The Treyid of Evolutionary Thought. 17 



Among those who have done much to popularise vitalism 

 Samuel Butler deserves special mention. He is best known as 

 the exponent of the " memory " theory of development.* He 

 was not the first to put forward this theory, as Hering, Semon, 

 and others had adopted it, but Butler made an efif'ective appeal 

 to the public. He shows that consciousness and volition have a 

 tendency to vanish when practice has rendered any habit 

 exceedingly familiar ; and says if we admit that the mere 

 presence of an elaborate but unconscious performance carries with 

 it a presumption of infinite practice, we shall find it impossible 

 to draw the line at those actions which we see acquired after 

 birth. " The developing chick," he maintains, " works with such 

 absolute certainty [making flesh, bones, feathers, &c.], and so 

 vast an experience that it is utterly incapable of following the 

 operations of its own mind — as accountants have been known to 

 add up long columns of pounds, shillings and pence, running the 

 three fingers of one hand, a finger for each column, up the page, 

 and putting the result down correctly at the bottom, apparently 

 Avithout an effort." 



Many others have adopted the theory that development is 

 guided by memory, and among the most important of its 

 advocates is Sir Francis Darwin, whose presidential address to 

 the Botany Section of the British Association (1908) urges its 

 importance. Darwin says : '' It seems to me certain that in 

 development Ave have an actual instance of habit." And he 

 adds : "If this be so, somatic inheritance must be -a vera causa." 



Yet another supporter of neo-Adtalism is Bergson, Avho has 

 done much to interest thinking people in life and heredity. He, 

 like Butler, lays great stress on memory, Avhich he regards as one 

 of the marked characteristics of life. But his great idea is that 

 there is in life a great impetus, that floAvs like a stream from 

 generation to generation, gathering experience as it flows 

 onwards, perpetually adapting itself, constantly creating some- 



* See liis '"Life and Habit," ''Unconscious Memory,"' and other 

 works. 



