146 Charles Darwin. 



was begun in i860, and published eight years later. 

 The facts collected for this covered many years, v/hile 

 the actual time in the preparation of the volume 

 represented over four years. A second edition, re- 

 vised and corrected, followed in 1875. While col- 

 lecting material for his great work on the " Origin of 

 Species," 1837, Darwin became convinced that man 

 in his present form was the outcome of the evolu- 

 tionary law, and as a result of his speculations on 

 the question we have the " Descent of Man," pub- 

 lished in 1 87 1, to which he gave three years of his life 

 —years of intense application, broken only by the 

 inroads of ill-health. This production added fuel to 

 the flame of criticism, and was the sensation of the 

 day, resulting in an almost endless controversy, 

 which extended from the pulpit to the workshop. 



In all these works we see that Darwin had con- 

 ceived the ideas years before, had been collecting 

 data and working them out through a quarter of a 

 century, and his next publication, the " Expressions 

 of the Emotions of Animals," was the result of simi- 

 lar methods. 



In 1839 his first child was born, and its expres- 

 sions and emotions excited not only the intense 

 paternal love that was dominant in his nature, but a 

 desire to observe carefully the gradual development 

 of the human intellect. Almost daily notes were 

 made which will be found in the work given to the 

 world in 1872. This, too, was an immediate success, 

 5,227 copies being sold on the day of publication, and 

 the book, like all the others, is still in active demand. 



One of the most charming of Darwin's works, to 

 either layman or scientist, is his " Insectivorous 



