PREFACE 



can follow my argument at least in the main. At the same 

 time I bring the reader at once into the arena of conflicting 

 biological thought, for only thus, I think, can he realize the 

 status of the science to-day. I trust that what to biologists 

 are well-known facts I have presented in a manner that 

 elicits their interest. 



Together with a definition of the general problems, my 

 own work as well as my ideas are presented. The out- 

 come of these is my theory which I set forth in a more 

 explicit manner than heretofore. 



The conception upon which the book is built, though 

 latent in my earlier researches, did not come fully awake 

 until 1930 while I was enjoying the hospitality of the 

 Kaiser-Wilhelm-Institut fiir Biologic at Berlin-Dahlem. 

 There I fell under the inspiration of Adolf von Harnack's 

 personality. I like to feel that my work was influenced by 

 the rich experience of personal contact with him. 



The studies which gave rise to my conception were made 

 during some twenty years, largely at the Marine Biological 

 Laboratory, Woods Hole, Mass.; some few were made at the 

 Zoological Station at Naples. For the support of many of 

 these researches I am indebted to the late Mr. Julius 

 Rosenwald, whose friendship I esteemed. However, this 

 book could not have been finished but for the spontaneous 

 and sympathetic understanding of my work shown by Dr. 

 F. W. Keppel, President of the Carnegie Corporation. A 

 grant from this corporation made possible a year's study 

 necessary to complete the work. In the task of writing a 

 book understandable also to non-biologists, I have further 

 been sustained and encouraged by many friends, biologists, 

 medical men, and others outside of these fields. 



The book may be divided Into three parts. Part I, com- 

 prising Introduction, Life and Experiment, Protoplasmic 

 System, Ectoplasm, General Properties of the Ectoplasm 

 and Water, though dealing primarily with the animal egg, 



ix 



