INTRODUCTION. 3 



his great work, 'Generelle Morphologie' (1S66), has recently (1868, 

 with a second edit, in 1870), published his 'Natiirliche Schop- 

 fungsgeschichte,' in which he fully discusses the genealogy of 

 man. If this work had appeared before my essay had been writ- 

 ten, I should probably never have completed it. Almost all the 

 conclusions at which I have arrived I find confirmed by this natur- 

 alist, 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 authority in the text; other statements I 

 leave as they originally stood In my manuscript, occasionally giv- 

 ing 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.'^ Consequently the second part of 

 the present work, treating of sexual selection, has extended to an 

 inordinate length, compared with the first part; but this could not 

 be avoided. 



1 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 main- 

 tains that man is endowed with certain muscles solely for the 

 sake of expressing his emotions. As this view is obviously op- 

 posed to the belief that man is descended from some other and 

 lower form, it was necessary for me to consider it. I likewise 

 wished to ascertain how far the emotions are expressed in the 

 same manner by the different races of man. But owing to the 

 length of the present work, I have thought it better to reserve my 

 essay for separate publication. 



Theorie:' zweite Auflage, 1868, von Dr. L. Buchner; translated into 

 French under the title 'Conferences sur la Theorie Darwinienne,' 1869, 

 'Der Mensoh, im Lichte der Darwin'sche Lehre,' 1865, von Dr. F. 

 Rolls. I will not attempt to give references to all the authors who have 

 taken the same side of the question. Thus G. Canestrini has published 

 ('Annuario della Soo. d. Nat.,' Modena, 1867, p. 81) a very curious 

 paper on rudimentary characters, as bearing on the origin of man. 

 Another work has (18C9) been published by Dr. Francesco Barrage, 

 bearing in Italian the title of "Man made in the image of God, was 

 "also made in the image of the ape." 



2 Prof. Hackel was the only author who, at the time when this work 

 first appeared, had discussed the subject of sexual selection, and had 

 seen Its full importance, since the publication of the 'Origin' ; and this 

 he did in a very able manner in his various works. 



