THE BIRD AS A TRAVELLER 67 



they always seem to House People, as flock after flock 

 gathers and disappears. You can watch them some- 

 times passing by day so high in the sky that they seem 

 like dust-motes — then perhaps you will only hear a 

 faint call-note and see nothing. At night the sound 

 of many voices falls from the clouds. Sometimes it 

 will be the tinkling bell of Bobolinks, sometimes the 

 feeble peep of Snipes, and sometimes the hoarse honk 

 of Wild Geese." 



"Why, Uncle Roy! Can you tell a bird's name 

 without seeing it, only by one little cry?" 



" Yes, my lad. When you have lived with birds as 

 long as I have, you will know their different voices as 

 you do those of your own family. When some one 

 calls you in the garden, can't you tell whether it is 

 Dodo or Olive ? " 



" Yes, but their voices are so veri/ different." 



" So are the voices of birds, when you know them 

 well." 



" But the young birds who have been hatched up 

 here — how do they know aijout going the first time? " 

 asked Rap. 



" The young ones are led in their journeys with 

 signals and cries b}' their parents ; they iii turn lead 

 their own 3^oung, and so the knowledge is kept up end- 

 lessly." 



" I can see why they go south," said Rap, after think- 

 ing a few moments, " but why do they come back 

 again? Why don't they stay and build their nests 

 down there ? " 



"That is a difficult question to answer," said the 

 Doctor, "and one that we House People try to ex- 



