viii PREFACE, 
IX.—Taz DevetopmMent or Human RackEs UNDER 
tHe Law or Natura. SELECTION. 
First published in the ‘ Anthropological Review,” 
May, 1864. Now reprinted with a few important alter- 
ations and additions. I had intended to have consider- 
ably extended this essay, but on attempting it I found 
that I should probably weaken the effect without add- 
ing much to the argument. I have therefore preferred 
to leave it as it was first written, with the exception 
of a few ill-considered passages which never fully ex- 
pressed my meaning. As it now stands, I believe it 
contains the enunciation of an important truth. 
X.—Tue Limits or Naturat SELECTION AS APPLIED 
To Man. 
This is the further development of a few sentences 
at the end of an article on “ Geological Time and the 
Origin of Species,” which appeared in the “ Quarterly 
Review,” for April, 1869. I have here ventured to 
touch on a class of problems which are usually consi- 
dered to be beyond the boundaries of science, but 
which, I believe, will one day be brought within her 
domain. 
For the convenience of those who are acquainted 
with any of my essays in their original form, I sub- 
join references to the more important additions and 
alterations now made to them. 
