PEEFACE xiii 



the Great War. MetchnikofE describes Kovalevsky 

 as a young man, small and timid, with shy but cordial 

 manners and the clear sweet eyes of a child : he had 

 (like MetchnikofE) for Science an absolute cult — " no 

 sacrifice was too great, no difficulty too repellent for 

 his ardour." 



It is, I think, desirable to assure the reader of 

 this book that the actual state of knowledge in 

 regard to various subjects discussed in the Life at the 

 time when they were made the subjects of study by 

 Metchnikoff is fairly and correctly sketched, and the 

 growth and development of his views and original 

 discoveries are correctly given. But it must be 

 remembered that this lAfe is not a critical discussion 

 of the steps by which our knowledge of cell-layers, 

 of intracellular digestion, and other factors con- 

 tributory to MetchnikofE's doctrine of Phagocytosis 

 and its outcomes were reached. Others played an 

 important if a subsidiary part in building up that 

 knowledge. What we have here is an account of 

 the growth of MetchnikofE's own observations and 

 theoretical inferences, which were so independent, and 

 founded on such decisive original observations, as to 

 make him a solitary figure contending, and successfully 

 contending, during the best years of his lifetime for 

 the recognition of a great generalisation for long 

 opposed by most of the medical and physiological 

 authorities of the time, and finally established by his 

 lifelong researches and those of his faithful pupils 

 and coadjutors. The recognition of the validity of 



