VI. PREFACE 



amoebae of all sorts, for they have always been with me favourite objects 

 of investigation ; and I probably realize more clearly than most men 

 how very little is really known and understood concerning these remark- 

 able organisms. I confess, indeed, that I still regard them as in many 

 ways the most difficult to investigate of all living animals. No one man 

 will ever succeed in solving all the myriad problems which they present : 

 and it is merely as a small contribution to what must ultimately be the 

 work of many, that these pages are submitted to the judgement of all 

 fellow-workers seeking after truth. 



April, 1919. C. D. 



