122 TWO DAYS IN WENSLEYDALE. 



I have already endeavoured in another place (the " Supplement to the 

 Yorkshire Flora ") to investigate and explain the manner in which the dif- 

 ferent assemblages of species, called by geographical botanists "types of 

 distribution," unite and combine together to form the vegetation which 

 clothes the surface of our county. Out of a thousand more or less strictly 

 native species of flowering plants and ferns which it produces, it is there 

 shewn, that whilst 57 per cent, are diffused generally throughout Britain, 

 31 per cent, are absent from the northei-n, and 9 per cent, from the southern 

 portions of the island. Whatever part of the county be visited, it Avill be 

 found, as a general rule, that it is species of the "universal" class which 

 make up the main body of the vegetation ; and that, allowing for situation, 

 the differences between the aspect of the flora of different parts is caused by 

 the absence or presence of the species which compose the remaining classes. 

 The flora, therefore, of any portion of the central vale, may be characterized 

 as composed mainly of " universal " species, with a large admixture of those 

 {"austral" species) which run out in a northern dii-ection. Since the days of 

 Toui'nefort and Bembo it has been a familiar fact, that a district elevated 

 above the sea corresponds in its flora to a level tract of the country more or 

 less further northward, in proportion to its elevation. So that, (to state the 

 facts of the case in the form of generalization,) a botanist who travels from 

 the bottom towards the head of a vallej^ like Wensleydale, gradually leaves 

 behind the "austral" species, one after another, as he advances; and every 

 now and then, meets with a fresh northern, or " boreal" species, intermingled 

 amongst the general body of the vegetation ; which, as stated before, always 

 consists of those species which are distributed throughout the whole extent 

 of the island. And if he be a resident in towns and cities, who only finds 

 opportunity for an occasional or periodical ramble amongst the mountains, 

 he soon learns to regard these boreal species (which, if confidence may be 

 placed in the theory of the late lamented Professor Edward Forbes, are 

 fragmentary relics of the flora of the period which preceded the great glacial 

 inundation) with feelings of pecvxliar interest. But, of course, it is only a 

 faint glimpse of all this that a casual visitor catches. 



To return to Bedale, however. To occupy the time till my companion 

 should arrive, I walked out along the high road in a southern direction, for 

 a mile or two, and gathered Polygonum Fagopyrum, which had become 

 naturalised in considerable plenty upon rubbish heaps by the roadside, and 

 Geranium colunibinum; and noticed a single bush of Salix Forhyana, a species 

 of considerable i-arity. The Brambles of the hedgerows there appear to be 

 discolor, corylifolius, fusco-ater, nitidus, and ccesins. 



It was not long before my companion made his appearance, and then for 

 the westward in good earnest. Carperby is rather more than twenty miles 

 from Bedale by the shortest way ; but we preferred the plan of proceeding at 

 once to the Ure, the nearest point of which is about three miles from Bedale, 



