Darwin, Charles,  1809-1882 <br/><br/>
The Descent of Man and Selection in Relation to Sex, Vol. I  [electronic resource] / 
Charles Darwin 
 -  Project Gutenberg,  2011 
 - Project Gutenberg  34967 .
<br/><br/> Transcription of 1871 edition 
<br/><br/> Public domain in the USA. 
<br/><br/>Electronic text