PREFACE 



embodies principles which concern the fundamental organi- 

 zation of any living thing. Part II, including the Fertiliza- 

 tion-process, the Fertilization-reaction, Parthenogenesis, 

 Cell-division and Cleavage and Differentiation, discusses 

 in particular the problems that refer directly to animal eggs 

 in their earliest stages of development. Part III, embrac- 

 ing chapters on the Chromosomes and Ectoplasm, Ecto- 

 plasm and Evolution, and Conclusion, has to do with more 

 or less theoretical discussions. Throughout the whole 

 treatment, the principle that the cell is the biological umt is 

 kept in mind. In particular, structure and function of the 

 ectoplasm are emphasized; upon these my theory of the 

 state of being alive is in large measure grounded. 



Concerning the literature cited, I should point out that 

 I have made no attempt to refer to all of the many original 

 papers which I have studied and abstracted. Instead, with 

 each revision of the manuscript I have reduced the number 

 of titles in the bibliography. Nevertheless, the list of titles 

 retained is ample for the argument set forth. 



E. E. J. 



Paris, France, 



Novrynher , 1938. 



X 



