WILD LIFE OF ORCHARD AND FIELD 



dens and groves. Then, in the restful, medita- 

 tive days of autumn, the story is reversed. Birds 

 of which we caught a glimpse in spring grant us 

 a second brief interview, our summer friends are 

 assembling and departing, and presently only the 

 faithful few who reside with us the year around, 

 plus some winter visitors from boreal parts, will be 

 seen in our woods and meadows. 



It appears, then, that we in temperate latitudes 

 entertain two sets of annual visitors one from 

 the South and the other from the North. This is 

 true, and it looks as though the custom of migra- 

 tion had begun among birds wanderers by nat- 

 ure by their annually leaving the overcrowded 

 tropics for increasingly distant journeys, in the 

 course of which they built their nests; and that 

 after a while certain ones had got into the habit 

 of staying in the new regions, or of making only 

 short and partial migrations, which by -and -by 

 will cease. It is significant that most of the pro- 

 nounced migratory species are errant members 

 of families mainly tropical. 



We have in the middle parts of the United States 

 four classes of birds, regarded from this point of view : 



First Those which do not migrate at all, and 

 these are a goodly number. 



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