THE nr.cixxixas or sr/iixc, 15 



this spot, one of the wannest and most foru.ircl hill 

 districts in the south of ICn^danil, ^mvcs it an adventitious 

 value for every collector, and a real one for the student 

 of botanical history. Kvidentl)-, the hairy si)ur<;e as 

 here, and only here, because, bein^ a mountain species 

 of wanner climates, Claverton Down is the onl> hill in 

 Hritain at once hi.i^di enouLjh and warm enou^di to suit it. 

 This explanation sufficiently accounts for its absence 

 elsewhere, but not cpiite for its presence here. How did 

 it ^^et from the Continent to Claverton Down ? 



If the occurrence of the hairy spurj^e in Kn<,dand 

 were an isolated case, we mi^ht sui)i)osc that it had 

 been accidentally imported by man, or that the seed 

 had been blown here by the wind, or that it had been 

 carried over b)' clin^ini^ to the feet of birds. Such 

 accidents do undoubtedly account for many special facts 

 of distribution and acclimatisation — for example, all 

 oceanic islands, as Mr. Wallace has amply shown, are 

 peopled with mere waifs and strays of various distant 

 faunas and floras in just this fraij^mentary fashion. lUit 

 the case of the spur^^e is by no means a solitary one ; 

 on the contrary, the south-western districts of I'jij^dand 

 and of Ireland are full of peculiar species found in no 

 other parts of Britain. Thus a pretty little purple 

 lobelia, a familiar plant in southern France and Spain, 

 is alone found with us on a single common near Ax- 

 minster in Devon. So, too, Cornwall and the Scilly 

 Isles are rich in southern forms. The arbutus, or straw- 

 berry tree, which grows so abundantly, with its white 

 bcll-shapcd blossoms and its pretty red berries, over tlu: 

 l*rovcni;al hills, is met again quite unexpectedly on the; 

 mountains of Kerry. The Mediterranean heath— that 



