88 RAMBLES OF A NATURALIST. 



phenomena which modern science has been able to 

 elucidate in regard to the surface of the earth. It is 

 to the Gulf Stream that Bretagne generally, and 

 Brehat in particular, owes these climatic relations 

 which at first sight seem so extraordinary. This 

 great current of waters, after being warmed by the 

 heat of the equator and of the tropics, emerges from 

 the Gulf of Mexico, and taking the direction of 

 Europe, separates into different branches, one of 

 which, driven northward by the Spanish peninsula, 

 strikes upon the shores of Bretagne. Here it pene- 

 trates into the channel, and surrounds Brehat with 

 its still tepid waves. While, however, it protects 

 this little island from the rigour of winter, it entails 

 upon it an extreme degree of humidity, to which 

 medical men refer the rheumatic affections, and more 

 especially the stubborn forms of ophthalmia, which 

 afflict a large proportion of the population. 



Although Brehat presents considerable resem- 

 blance to the largest island of Chausey in respect to 

 the nature of its soil, climate and vegetation, it differs 

 in having an area eight or ten times larger. If we 

 bring this circumstance to bear in examining the 

 animals which inhabit this island, we shall find that 

 we may aptly apply to these two islands that beau- 

 tiful law of general zoology, which was propounded 

 by the genius of our great Buffon, and after having 

 been long denied by naturalists, is now daily ac- 

 quiring additional confirmation in proportion to the 

 constant advances made in science. Buffon laid it 

 down as a principle, that the numbers and size of the 

 different species of animals living upon a continent 



