PERSONALITY IN BIRDS 225 



look speaks rather than sings that short strain that 

 has in it the echo of a human regret. Both of these 

 songs are, as it were, negative reminiscential rather 

 than actual. But the song of the Nightingale suggests 

 no retrospect. It is positive, present, insistent, a 

 passionate protest, and he who hears it may read 

 into it what passion he will. It is of a kind with some 

 music that exults and despairs at once, carrying 

 the hearer away with no more reasonable warrant 

 than its own undefinable power. For the Nightin- 

 gale has taken the purity of tone and the smooth 

 phrasing of the finer Warblers ; the fire, and some of 

 the force of the Throstle ; and, with expression more 

 searching than that of the Willow-wren, has given to 

 the passion that was the little Wood-wren's despair, 

 its full and perfect utterance. Still, the Nightingale, 

 as a singer in the quiet of evening, perfect though his 

 song may be, touches no purely human chord. Its 

 song is an exquisite perturbation, disposing the mind 

 to unrest at an hour when it would fain have peace 

 with itself and cease for a while from the more 

 clamorous moods that belong to the day. 



It is as impossible to arrange birds in a linear series 

 according to their personalities as it is to set them 

 out in linear order in the classification of genera and 

 species. They fall rather into groups the members 

 each of which resemble one another generally, but 

 may at the same time in particular ways resemble 

 birds found in other natural groups, A truer 

 image of the correspondences and differences 

 existing among birds may perhaps be sug- 

 gested by casting several handfuls of pebbles into 

 different parts of a pond. The pebbles of each 



