DESCENT OF MAN. 187 



history." But he was anxious to justify this state- 

 ment, which was, of course, distasteful to very 

 many in those days, by a most complete treatment 

 of the subject. 



He opens this part of the work, which he calls 

 " The Descent or Origin of Man," by discussing the 

 structures which are common to man and animals, 

 including those which are represented in man in a 

 rudimentary state, and by showing the similarity of 

 the phases through which man and animals pass 

 during their embryological development. 



Having thus shown that man was probably de- 

 scended from some lower form, he considers the mode 

 by which the process was effected, showing that man 

 possesses variability in body and mind, and is, like 

 other animals, subject to all the laws of inheritance 

 and variation, and to the direct action of surrounding 

 conditions, and to the effect of the use and disuse 

 of parts, and that his rate of increase is such as to 

 render a large amount of extermination inevitable. 

 In other words, he presents the same facilities for 

 the operation of natural selection as those presented 

 by other animals. The points in which man differs 

 from other animals are then considered in relation 

 to their possible origin by natural selection. The 

 differences and resemblances between the mind of 

 man and animals are discussed in much detail, and 

 the origin of the former through natural selection 

 is defended. This part concludes with the considera- 

 tion of the position of man in the animal series, his 



