PREFACE TO THE FIRST EDITION. XXV 



history. Perhaps, at the same time, I may hope to con- 

 vince some of those specialists, who deal indeed daily 

 with the facts of germ-history, but who neither know nor 

 wish to know anything about the true causes of these, 

 which lie hid in tribal history. As this is quite the first 

 attempt to present the Ontogeny and Phylogeny of man in 

 their whole causal connection, I fear that, at best, the 

 point at which I aim lies far beyond the point gained. 

 But by this each thinking man will, it is to be hoped, be 

 convinced that only by recognizing this connection does 

 the history of human evolution become a science. On- 

 togeny can only be really understood through Phylogeny. 

 The history of the tribe lays bare the true causes of the 

 history of the germ. 



ERNST HEINRICH HAECKEL. 



Jena, July 13, 1874, 



