283 FACULTIES. OF BIRDS. 



of Germany, and return thither. The birds of song 

 and the summer birds come from the Greek Archipe- 

 lago, and return thither when the temperature ceases 

 to be mild in the Low Countries. A small number 

 of birds, drawn by the company of others, chased by 

 birds of prey, or driven by famine, depart from their 

 usual practice and make two migrations in the same 

 year. A small number of other birds are often se- 

 duced by the mildness of the temperature, and by the 

 abundance of food which they find, to prolong their 

 stay beyond the usual time, and even to spend the 

 winter in the Netherlands. The same circumstances 

 doubtless occur in other countries. 



In conclusion, the migration of birds is a subject 

 on which comparatively few observations have yet 

 been made. Even the precise periods of their ap- 

 pearance and disappearance in different parts of 

 Europe have not been noted with the necessary 

 degree of attention ; and until persons properly qua- 

 lified shall undertake the task, we must remain 

 contented with vague notices and unfounded conjec- 

 tures. The migration of fishes, which is an equally 

 wonderful if not equally interesting phenomenon, is 

 in a great measure placed beyond our investigation ; 

 but that of birds, being observable by any individual 

 residing in the country or making daily excursions 

 to it, and sufficiently acquainted with the species, 

 might be illustrated by simultaneous exertions made 

 at different stations along the coasts and in the 

 interior. 



