'^ FRANK C. BAKER, 

 ^^1^ ^. Chicago, Ills 



PREFACE TO THE SECOND EDITION. 



During the successive reprints of the first edition of 

 this work, published in 1871, I was able to introduce sev- 

 eral important corrections; and now that more time has 

 elapsed I have endeavored to profit by the fiery ordeal 

 through which the book has passed, and have taken ad- 

 vantage of all the criticisms which seem to me sound. I 

 am also greatly indebted to a large number of correspond- 

 ents for the communication of a surprising number of new 

 facts and remarks. These have been so numerous that I 

 have been able to use only the more important ones; and 

 of these, as well as of the more important corrections, I 

 will append a list. Some new illustrations have been in- 

 troduced and four of the old drawings have been replaced 

 by better ones, done from life by Mr. T. W. Wood. I 

 must especially call attention to some observations which I 

 owe to the kindness of Prof. Huxley (given as a supple- 

 ment at the end of Part I), on the nature of the differences 

 between the brains of man and the higher apes. I have 

 been particularly glad to give these observations, because 

 during the last few years several memoirs on the subject 

 have appeared on the Continent and their importance has 

 been, in some cases, greatly exaggerated by popular writers. 



I may take this opportunity of remarking that my critics 

 frequently assume that I attribute all changes of corporeal 

 structure and mental power exclusively to the natural se- 

 lection of such variations as are often called spontaneous; 

 whereas, even in the first edition of the " Origin of 

 Species,^' I distinctly stated that great weight must be at- 



