246 THE ZOOLOGIST. 



counties only awaiting discovery there. I am not aware of any 

 records from Scotland, Ireland, or the isles lying off Britain. A 

 specimen is said to have been taken in Jersey, but this was not 

 authenticated. Specimens of the Long-tailed Field Mouse type 

 from that island which I have seen were all sylvaticus, though 

 certainly of a richer colour than those of the mainland. I have 

 a flat skin of a sylvaticus Mouse from Jersey, which, in the 

 brightness of its pelage, very nearly rivals fiavicollis. As I write 

 this, word has been brought to me that a number of fiavicollis 

 were trapped in the cellar of a house in this neighbourhood 

 (Godalming), where they had attacked a store of potatoes. 

 Intelligent country people here easily discriminate between Mus 

 fiavicollis and sylvaticus, one man having informed me that the 

 former were " as large as young Eats." Mus sylvaticus enjoys 

 a large share of popularity in the current zoological literature. 

 It has been studied perhaps more, or quite as much, as any other 

 British mammal. Its range includes nearly the whole of the 

 palsearctic * area, reaching the confines of the Oriental region in 

 Gilgit ; that is to say, if the Mus arianus of Blanford is identical 

 with the present species. This Mouse, which is termed the 

 Persian Long-tailed Field Mouse in the ' Fauna of British India,' 

 is thought by later authorities to be merely a variety of Mus 

 sylvaticus of Europe, perhaps hardly entitled to subspecificrank. 

 In many places throughout the vast palsearctic area, Mus sylva- 

 ticus has, under varied climatic influences, formed many species, 

 races, or variations, whatever its numerous bibliographers choose 

 to term them. Being hardy and exceedingly prolific, it is not 

 hard to understand how this Mouse has won its way through 

 the enormous area it inhabits in the struggle for existence. Even 

 on bleak, wave- surrounded St. Kilda it is found, having here 

 adopted a further variation from the type, and is thought by some 

 to be, if not specifically distinct, entitled to at least rank as a sub- 

 species, and has been named Mus hirtensis. Judging from the 

 plate of this Mouse (Proc. Zool. Soc. Lond. 1899, pl.ix.), the speci- 

 men figured appears to be a variety of fiavicollis rather than sylva- 

 ticus. One of the most interesting problems in zoology is how an 

 island so remote from the mainland gets colonised by mammals. 



'■'• It is said that the only mammal indigenous to Iceland is Mus 

 sylvaticus. 



