PREFACE 



The present book is an attempt to state, and to 

 present some of the evidence in favor of, a conception of 

 the nature of organic individuality which has gradually 

 developed in the mind of the writer during the course of 

 some fifteen years' investigation of the simpler processes 

 of reproduction and development in the lower animals. 

 In these forms organic individuality appears in rela- 

 tively simple terms, and it is here if anywhere that we 

 must look for the key to the problem of individuality in 

 the higher animals and man. 



With the great variety of facts at hand and the 

 limited space available, it has often been difficult to 

 decide what particular points of the evidence to include 

 in the consideration and what to omit. To those 

 familiar with biological facts it will doubtless be evident 

 that many data from various lines of investigation have 

 been either barely mentioned or entirely omitted. 



The attempt has been made to show in some degree 

 the wide range of applicability of this conception of 

 individuality to various biological fields, and it is per- 

 haps permissible to express the hope that, not only the 

 physiologist and botanist, but also the neurologist, the 

 psychologist, and the sociologist may find something 

 of interest in it. Chaps, i and ii are necessarily some- 

 what abstract and condensed and may seem to some 

 readers to demand too extensive a background of bio- 

 logical knowledge. A re-reading of these chapters 

 after reading chaps, iii-vi will assist in decreasing this 

 difficulty. 



In the book Senescence and Rejuvenescence , recently 

 published, the writer was chiefly concerned with the 



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