154 WONDERS OF ORGANIC LIFE. 



leaves the stream for wider water-courses — or 

 irregular, as in the case of the migration of 

 herrings in the north, or of clouds of locusts in 

 Asia or Africa. We will first attend to perfect 

 and regular migration, as we see it performed 

 by " birds of passage." 



Our island is well situated for observing the 

 phenomena of migration, which, viewed from it, 

 may be likened to a tide-stream, flowing north- 

 wards in spring, with a southern reflux in 

 autumn. We may say, indeed, that our island 

 is an Africa to the wild fowl of the Arctic 

 regions, and an Arctic breeding-place to the 

 swallow, which winters in Africa. Let us paint 

 a summer in the Arctic regions. It is very 

 short, but short as it is, it sees the birth of 

 thousands of most interesting beings, and every 

 islet and every promontory is thronged by a 

 dense population. As if by magic, the snows of 

 winter have dissolved, and coarse herbage has 

 covered the land. Every small pool, every 

 lake, every inlet, is garlanded with vegetation. 

 Driving onwards from the south, (our tem- 

 perate latitudes,) arrive myriads of wild-fowl, 

 water birds of various species, scoter ducks, 

 widgeons, eider ducks, king ducks, pochards, 

 etc., and also several species of wading birds. 

 The work of incubation now commences. The 

 ground is converted into a city of nests, rarely 

 intruded upon by the foot of man. Here 

 myriads of wild fowl are reared. The water 

 supplies them with food — the reeds bend over 

 their nests — 



