370 CHAELES ROBERT DARWIN. 



ceived replies. He used to say that if he did not 

 answer them, he had it on his conscience after- 

 wards, and, no doubt, it was in great measure the 

 courtesy with which he answered every one which 

 produced the universal and widespread sense of 

 his kindness of nature which was so evident on 

 his death." 



In November, 1853, Darwin received the Eoyal 

 Society's Medal. He was gratified, finding it "a 

 pleasant little stimulus. When work goes badly, 

 and one ruminates that all is vanity, it is pleasant 

 to have some tangible proof that others have 

 thought something of one's labors." 



November 24, 1859, when Darwin was fifty, his 

 great work, " Origin of Species by means of Natu- 

 ral Selection, or the Preservation of Favored Kaces 

 in the Struggle for Life," was published. For 

 twenty years he had been making experiments 

 with plants and animals, and filling his note-books 

 with facts. To his old classmate, Fox, he writes 

 asking that the boys in his school gather lizards' 

 eggs, as well as those of snakes. " My object is," 

 he says, a to see whether such eggs will float on 

 sea-water, and whether they will keep alive thus 

 floating for a month or two in my cellar. I am 

 trying experiments on transportation of all organic 

 beings that I can ; and lizards are found on every 

 island, and therefore I am very anxious to see 

 whether their eggs stand sea-water." Again he 

 writes, asking Fox for ducklings and dorkings; 

 "The chief point which I am and have been for 



