PREFACE TO THE ENGLISH EDITION. 



TN preparing for the English-reading student this version of 



M. Metchnikoff's latest work, wherein he "sums up the labours 

 of twenty-five years," it has been my aim to give a faithful rendering 

 of the ideas and argument of the original, even at the risk of an 

 occasional crude expression, rather than to attempt to reproduce 

 the brilliancy of the original by any wide verbal departure from 

 the text. 



The Table of Contents forms an admirable analytical summary of 

 the main subject-matters treated, but an alphabetical Index has been 

 added to the present edition, and, though not at all exhaustive, this 

 may serve as a key to the many authors cited and to the maze of 

 detail discussed in the work. 



The marginal reference to the pages of the original work will, 

 I hope, commend itself to those readers who may wish to refer to 

 the ipsissima verba of the author. It is, I believe, a novelty in 

 scientific works, though familiar in works in other departments of 

 literature. 



I am under deep obligations to Professor Woodhead (who has 

 read the whole of the proofs) and to Mr A. E. Shipley, and 

 Mr G. H. F. Nuttall (who have read portions) for much valuable 

 criticism and advice. 



THE TRANSLATOR 



August, 1905. 



