PREFACE 



IN March 1906 I delivered a lecture, entitled " The 

 Secret of the Cell," as one of the Westminster 

 Series for that year, in the Hall of Westminster 

 Cathedral. The arranger of those lectures, who is 

 also the Editor of this Series, asked me to expand 

 that necessarily much compressed discourse of 

 mine into a book, and the result is now in the 

 reader's hands. As the book is avowedly an 

 expansion of that lecture I have not hesitated to 

 use the same arguments, the same examples and 

 even in some cases the same phraseology. But I 

 have tried to explain more fully matters which 

 I was obliged to pass over far too briefly in the 

 lecture,, and I have also added a very large amount 

 of new matter and examples. 



I hope that I have confessed my indebtedness 

 to the many writers whose works I have consulted 

 whilst drawing up this summary of the Vitalistic 

 position. There is one, however, whose name must 



