I. 



T is a well-known fact, which moreover impresses 

 itself upon every naturalist, 4 ur 'i, n g m ' s passage north 

 along the coast of Norway, "that the" number of 

 species of birds decreases t;o sftf. 'e'xtraordirte'ry, extent 

 towards the north," while-' 'Oft 'the 'other hand the 

 number of individuals increases so considerably, 

 that hardly anywhere else in our continent do we see bird-life 

 more richly displayed, than just when we stand on the furthest 

 point of North Europe facing the Arctic Ocean. 



It is especially in the great colonies, "The Bird Rocks," 

 where this swarming bird-life exists. 



Such bird rocks make their appearance at intervals along the 

 whole of the coast of Norway from Stavanger, off and on, up to 

 Varangerfjord and the Russian frontier, exactly as we know them 

 on the coasts of Scotland and of the Faroe Isles. But while the 

 bird-rocks of these districts, the west-European on the one side, 

 and the Norwegian on the other, have of course, most of their 

 breeding species in common, as for instance the Guillemot and 

 Razorbill, the Puffin, the Cormorant and Shag, besides some 

 gulls, especially the Kittiwake (or " Three-toed Gull," Rissa 

 tridactyla): it is remarkable that the Norwegian bird-rocks 

 wholly lack several species, which form to some extent their chief 

 occupants in the west-European district. 



This is not only the case with the more pelagic species, which 

 belong to the more open parts of the Atlantic, as for instance the 

 two Petrels (Procellaria pelagica, and P. leucorrhoa), the Gannet 

 (Sula bassana), and the characteristic Shearwaters (Puffinus anglorum 

 and P. major), which certainly occur occasionally on the Nor- 



