PREFACE. Vll 



number of individuals prevailing in different parts of the island. 

 The plants which appear on particular soils attract such land 

 birds as feed upon their seeds. The submarine rocks and grounds 

 on which sea-weeds grow plentifully so as to afford shelter to the 

 minute fishes, and the molluscous and crustaceous animals on 

 which the wading and swimming birds feed, tempt them in greater 

 numbers to the neighbouring shores. The oozy, the sandy, the 

 gravelly, the stony, the rocky beach, has each its favourite species, 

 as has every peculiar natural or artificial feature of a country from 

 the level of the sea to the most lofty mountain summit. 



The difference in climate between Ireland and Great Britain 

 cannot be said to deprive the former island of any species found 

 in the latter. The comparative mildness of winter in the more 

 western island has, however, great influence on birds. Even in 

 the north of Ireland, a few land species, considered as birds of 

 passage in England, except in the extreme south, become resi- 

 dent ; and some grallatorial birds remain throughout the winter, 

 although found only in the south of England at this season. The 

 soft-billed birds also being generally able to procure abundance of 

 food, are by the comparatively high temperature, more inclined to 

 song at this period of the year. The humidity of the climate, 

 together with the great extent of bog throughout the island, 

 brings hither to winter, different species of grallatorial and other 

 birds, in much greater numbers than prevail in England or 

 Scotland. The extent of moist and rich meadows in summer 

 has a similar, but more limited, influence. The want of extensive 

 districts of old timber seems, when fully considered, to have little 

 effect in excluding from Ireland species which inhabit Great 

 Britain. 



To the laws of geographical distribution alone must, I conceive, 

 be attributed our want of species not affected by any of the 



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