308 BIRDS AND MAN 



a very considerable increase of knowledge since 

 his day; nevertheless, judging from something I 

 had said on the hibernation, or torpid condition, 

 of swallows, there was stiU something to learn 

 with regard to the life and conversation of 

 animals. The change in the character of modern 

 books about nature, of which I had told him, 

 quoting passages — a change in the direction of 

 a more poetic and emotional treatment of the 

 subject — he, looking from a distance, was inclined 

 to regard as merely a literary fashion of the time. 

 That anything so unforeseen had come to pass, — 

 so important as to change the current of thought, 

 to give to men new ideas about the unity of nature 

 and the relation in which we stood towards the 

 inferior creatures, — he could not understand. It 

 should be remembered that the human race had 

 existed some fifty or sixty centuries on the earth, 

 and that since the invention of letters men had 

 recorded their observations. The increase in the 

 body of facts had thus been, on the whole, 

 gradual and continuous. Take the case of the 

 cuckoo. Aristotle, some two thousand years 

 ago, had given a fairly accurate account of its 

 habits; and yet in very recent years, as I had 



