PKEFACE TO THE SECOND EDITION. 



Ddring the successive reprints of the first edition of this Tvork, 

 published, in 1871, I was able to introduce several importanl 

 corrections; and now that, nfore time has elapsed, I have 

 endeavoured to profit by the fiery ordeal through which the 

 book has passed, and have taken advantage of all the criticisms 

 which seem to me sound. I am also greatly indebted to a large 

 nximber of correspondents 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 introduced, 

 and four of tl\e old drawings have been replaced by better ones, 

 done from life by Mr. T. W. Wood. I must especially call 

 af'ention to sonie observations which I owe to the kindness oi 

 Prof. Huxley (given as a supplement at the end of Part I.), rm 

 the nature of the differences between the brains of man and the 

 higher apes. I have been particularly glad to give these obser- 

 vations, because during the last few years several memoirs on the 

 subject have appeared on the Continent, and their innportance 

 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 selection 

 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 attributed to the inherited 

 effects of use and disuse, with respect both to the body and 

 mind. I also attributed some amount of modification to the 

 direct and prolonged action of changed conditions of life. Some 

 Hllowance, too, must be made for occasional reversions of 



