INTRODUCTION. 15 



selves, it is the extraordinary that develops what is 

 really in us. We give full credit to the cunning fox 

 and wary trout, because we know them so well ; we 

 admire the caution of the crow, because it is set before 

 us continually, and drift into the belief that these are 

 exceptional cases ; but it is not so, as will be found 

 out when we know all other creatures as well as we 

 know those that I have mentioned. Perhaps we 

 never will, but this is to be hoped, for such knowledge 

 will lead to a more humane treatment of them all, 

 even the despised worms of the dust. 



It is so rarely mat we meet with a person who is 

 indifferent to birds that we may say of them that 

 they are a necessity to our surroundings, unless pent 

 up in town. Certainly when we walk afield and 

 neither see nor hear them, there is a feeling of desola- 

 tion that destroys the pleasure of an outing. The 

 lusty growths of summer are not enough of them- 

 selves : they are but the set scenes of a stage whereon 

 no actor treads ; but, on the other hand, we have but 

 to place a singing-bird in a bare bush, and we forget 

 that there are no leaves and flowers. 



Perhaps no one phase of bird-life has received 

 more careful attention than that of migration. The 

 word needs no definition, but the act still calls for 

 considerable explanation. A very large proportion 

 of the birds of this country pass their summers in 

 the north and their winters in the south : this is called 

 migration ; but it is not a uniform matter, and the 

 length of the migratorial journey varies exceedingly, 

 and with some species it has materially shortened in 

 recent years, or else the observers of a century ago 



