320 



ISLAND LIFE. 



[part II. 



Plants, which have considerable facilities for passing over the 

 sea, are somewhat intermediate in proportionate numbers, there 

 being about 970 flowering plants and ferns in Ireland to 1425 in 

 Great Britain, — or almost exactly two-thirds, a proportion inter- 

 mediate between that presented by the birds and the mammalia. 



Peculiar British Birds. — Among our native mammalia, reptiles, 

 and amphibia, it is the opinion of the best authorities that we 

 possess neither a distinct species nor distinguishable variety. In 

 birds, however, the case is different, since some of our species, 

 in particular our coal- tit [Parus ater) and long-tailed tit (Parus 

 caudatics) present well-marked differences of colour as compared 

 with continental specimens ; and in Mr. Dresser's work on the 

 Birds of Europe they are considered to be distinct species, while 

 Professor Newton, in his new edition of YarrelFs British Birds, 

 does not consider the difference to be sufficiently great or suffi- 

 ciently constant to warrant this, and therefore classes them as 

 insular races of the continental species. We have, however, 

 one undoubted case of a bird peculiar to the British Isles, in the 

 red grouse {Lagopus scoticus), which abounds in Scotland, Ireland, 

 the North of England, and Wales, and is very distinct from any 

 continental species, although closely allied to the willow grouse 

 of Scandinavia. This latter species resembles it considerably in 

 its summer plumage, but becomes pure white in winter ; whereas 

 our species retains its dark plumage throughout the year, be- 

 coming even darker in winter than in summer. We have here 

 therefore a most interesting example of an insular form in our 

 own country ; but it is difficult to determine how it originated. 

 On the one hand, it may be an old continental species which 

 during the glacial epoch found a refuge here when driven from 

 its native haunts by the advancing ice ; or, on the other hand, it 

 may be a descendant of the Northern willow grouse, which has 

 lost its power of turning white in winter owing to its long re- 

 sidence in the lowlands of an island where there is little permanent 

 snow, and where assimilation in colour to the heather among 

 which it lurks is at all times its best protection. In either case 

 it is equally interesting, as the one large and handsome bird 

 which is peculiar to our islands notwithstanding their recent 

 separation from the continent. 



