NUMBEK OF SPECIES. 45 



a rushing stream, dividing beautifal hay-meadows, and edged 

 with dwarf willows ; and during the half-hour I sat there, I 

 neither saw nor heard a single bird. In such a spot in 

 England there would have been plenty. But this is an 

 exception : the rule is, that you may read wherever you run, 

 if you will keep your eyes and ears open, and learn by 

 experience where chiefly to be on the look-out. Variety is 

 more interesting than numbers; the birds are more obvious 

 from their comparative variety ; and their voices are not lost, as 

 is sometimes the case with us, in a general and unceasing 

 chorus. As regards the number of species in the country, 

 I have never seen an accurate computation of it. But looking 

 over Mr. Dresser's very useful catalogue of the Birds of 

 Europe, I calculate roughly that it would amount to about 300 

 in all; i.e. less by some 70 or 80 than the avi-fauna of the 

 British islands. This is however a remarkably large number 

 for a country that possesses no sea-board and very few of thos6 

 sea-birds which form so large a contingent in our wonderful 

 British list ; and it suggests a few remarks on the causes which 

 bring some birds to the Alps periodically, and have tempted 

 others to make them their permanent home. 



The greatest attractions for birds, and therefore the chief 

 agents — as far as our present knowledge reaches — in inducing 

 birds to move from place to place are food and variety of 

 temperature. Now in the Alps we find these conditions of 

 bird-life everywhere present, except, of course, in the very 

 highest levels of snow and ice. The seed-eating birds find 

 sufficient in the rich hay, thick and sweet with flowers, which 



