Introduction. 



any degree new. Lamarck long ago came to this conclusion, 

 which has lately been maintained by several eminent naturalists 

 and philosophers ; for instance, by Wallace, Huxley, Lyell, Vogt, 

 Lubbock, Buchner, Eolle, &C., 1 and especially by Hackel. This 

 last naturalist, besides his great work, ' G-enerelle Morphologie ' 

 (1866), has recently (1868, with a second edit, in 1870), pub- 

 lished his ' Naturliche Schopfungsgeschichte,' in which he fully 

 discusses the genealogy of man. If this work had appeared 

 before my essay had been written, I should probably never have 

 completed it. Almost all the conclusions at which I have 

 arrived I find confirmed by this naturalist, whose knowledge on 

 many points is much fuller than mine. Wherever I have added 

 any fact or view from Prof. Hackel's writings, I give his autho- 

 rity in the text ; other statements I leave as they originally stood 

 in my manuscript, occasionally giving in the foot-notes references 

 to his works, as a confirmation of the more doubtful or interesting 

 points. 



During many years it has seemed to me highly probable that 

 sexual selection has played an important part in differentiating 

 the races of man ; but in my ' Origin of Species ' (first edition, p. 

 199) I contented myself by merely alluding to this belief. When 

 I came to apply this view to man, I found it indispensable to 

 treat the whole subject in full detail. 2 Consequently the second 

 part of the present work, treating of sexual selection, has ex- 

 tended to an inordinate length, compared with the first part ; 

 but this could not be avoided. 



I had intended adding to the present volumes an essay on the 

 expression of the various emotions by man and the lower animals. 

 My attention was called to this subject many years ago by 

 Sir Charles Bell's admirable work. This illustrious anatomist 



1 As the works of the first-named Nat.,' Modena, 1S67, p. 81) a very- 

 authors are so well known, I need curious paper on rudimentary cha- 

 not give the titles ; but as those of racters, as hearing on the origin of 

 the latter are less well known in man. Another work has (1869) 

 England, I will give them : — ' Sechs been published by Dr. Francesco 

 Vorlesungen iiber die Darwin'sche Barrago, bearing in Italian the title 

 Theorie :' zweite Auflage, 1868, von of "Man, made in the image of God, 

 Dr. L. Buchner ; translated into " was also made in the image of the 

 French under the title ' Conferences " ape." 



sur la Theorie Darwinienne,' 1869. 2 Prof. Hackel was the only 



' Der Mensch, im Lichte der Dar- author who, at the time when this 



win'sche Lehre,' 1865, von Dr. F. work first appeared, had discussed 



Uolle. I will not attempt to give the subject of sexual selection, and 



references to all the authors who had seen its full importance, since 



have taken the same side of the the publication of the 'Origin '; and 



question. Thus G. Canestrini has this he did in a very able manner in 



published ('Annuario della Soc. d. his various works. 



