PREFACE 



The first part has remained essentially as it was, 

 whereas of the second, which was illustrated 

 on the stage by Harder's wonderful panorama 

 and which no words could translate, only a part 

 has been used. At any rate the thought has 

 been more strongly expressed. The text is 

 fragmentary, — ^not because it is made up of 

 fragments of a lecture, but because a lecture 

 of two hours or a pamphlet on such a theme 

 necessarily can be no more than a fragment. 



The individual mosaic stones are now in fact 

 fitted into a whole, the whole is perfectly com- 

 prehensible without illustrations. Concerning 

 certain topics (the deep sea, the prehistoric 

 cave pictures) who ever wishes to go further 

 will find more exact accounts (also in popular 

 form but somewhat more rigid) in my books 

 "Aus der Schneegrube," "Weltblick" and "Von 

 Sonnen und Sonnenstaubchen." Those inter- 

 ested in heredity and memory are referred to 

 a passage in a lecture of the recently issued 

 and extraordinarily significant book by Rich- 

 ard Semon on "Die Mneme als erhaltendes 

 Prinzip im Wechsel des organischen Geschehens 

 zuriickfiihren." 



Friedrichshagen, April, 1905. 



Translator's Note. The illustrations in the 

 volume have been supplied by the translator 

 from various sources, principally from Haeck- 

 ePs "Kunstformen der Nature." 

 6 



