88 GEOGRAPHY OF ANIMALS IN SOUTH DEVO|N. 



try, or district. The former may be divided into the 

 vernal, or equatorial migration, the autumnal or polar 

 migration, and the straggling or irregular migration ; 

 whilst the latter comprises those internal shiftings 

 of abode, performed by certain animals, chiefly of 

 the higher classes. This division is quite arbitrary, 

 for the motives appear to be similar in each case, 

 that is to say, the obviating of inconveniences of 

 climate, the obtaining of food, the choosing of pro- 

 per situations for nestling, spawning, kc, instanced 

 chiefly among birds, in their above-named periodical 

 movements, and in quadrupeds, birds, fishes, and 

 some other animals of a lower order, in the case of 

 internal migrations. Besides these, there appear to 

 be other motives of which naturalists do not under- 

 stand the nature, causing the appearance of strag- 

 glers or irregular visitors. I say climate is certainly 

 the most decided and most universal impulse to the 

 mi<jration of animals, else how is it that their arrivals 

 and departures are adjusted in exact accordance to 

 the weather, and temperature, and these not only as 

 to time, but in some instances as to numbers, and 

 this statement applies to each kind of migration, 

 the straggling or uncertain migration even not being 

 perhaps excepted. Climate also in its most extended 

 sense influences greatly other subjects of our fauna, 

 besides the migratory tribes : the continuance of a 

 wind from either of the channels, or from the Atlan- 

 tic, or still more a storm, is sure to bring with it 

 certain of the pelagic birds and fishes, molluscous and 

 radiated animals, and indeed specimens in almost 

 every division of the animal kingdom, driven off the 

 coasts of other lands, or from the bosom and recesses 

 of the disturbed ocean. In severe winters, our or- 

 nithological fauna receives considerable augmenta- 

 tion, not only as to numbers of individuals of a spe- 

 cies, as above intimated but as to number of species ; 

 on such occasions, we participate largely in an 

 Arctic ornithology; sportsmen of every sort, amateur 

 and scientific ornithologists are abroad, and speci- 



