368 



DIFFUSION OF TERRESTEIAL ANIMALS. [Ch. XXXIX; 



have transported from the latter country the aphis, which 

 destroys the apple-tree, and two sorts of Nenroptera, the 

 Lucifuga and Flavicola, mostly confined to Provence and the 

 neighbourhood of Bordeaux, where they devour the timber 

 in the houses and naval arsenals. 



Among moUusks we may mention the Teredo navalis^ which 

 is a native of equatorial seas, but which, by adhering to the 



bottom 



HoUan d 



been most destructive to vessels and x^iles. The same species 



become 



enjoying an extensive commerce. BuUmiis undatus^ a land 

 species of considerable size, native of 



Jamaica 



West Indian islands, has been im 



Mr 



is now naturalised in the woods near that town. 



innumerable 



we may re- 



man 



anima 



Like them, we unconsciously 



limit the geographical range and 



numbers of certain species, in obedience to general rules in 



the economy of nature, which are for 

 our control. 



the most part beyond 



) 



^ 



\ 



, 



4 



