448 BOTANICAL GEOGRAPHY. 



Genista aspalafhoides evidently corresponds to the Rhododendra of the Alps, 

 the dwarf birch and the shrubby willows of the north ; formations which are 

 always considered as belonging to the alpiue region, or have been separated 

 from it as subalpine. Hence I propose the following regions for Granada, 

 which are comparable with those of other mountainous countries in the south 

 of Europe, and whereby the most remarkable circumstance, that the alpine 

 region has a very wide, and the central European a very narrow altitudinal 

 extent, vanishes when brought into relation with the general fact which I 

 have elsewhere determined, that in Europe the tree-limit does not ascend 

 southward of the Alps. 



A. Evergreen region. 0' 5000' (4500'). 



a. Region of Chamarops. 0' 2000'. (Boissier's hot region.) 



b. Region of the Cisti. 2' 5000' (4500'). (Boissier's mountainous 

 region.) 



B. Central European region, or pine-region. 5000' (4500') to 6500'. (Part 

 of Boissier's alpine region.) 



c. Alpine region. 6500' 11,000'. 



a. Region of alpine shrubs. 6500' 8000'. (Part of Alpine region.) 



b. Region of alpine shrubs and grasses. 8000' ll'OOO. (Boissier's 

 snow-region). 



But we must now follow Boissier's further description, and hence take in 

 the two regions which are contained in his alpine region. In the upper 

 part of it the snow settles even at the end of September, and the last masses 

 of snow do not melt until the commencement of June (hence corresponding 

 with the alpine region of the Alps), whilst in the lower part, the soil is only 

 covered with snow for four months (hence the climate of the Coniferous 

 region). The distribution of heat corresponds generally to the position of 

 the coasts ; the winter is not cold, and the temperature of the summer never 

 exceeds 77 E. The atmospheric precipitations are distributed over the 

 whole year ; in spring, and even throughout the summer, mists and thunder- 

 storms keep the soil moist, and this to a greater extent on the northern than 

 on the southern slope, which explains the greater abundance of plants on 

 the north side of the mountains ; consequently all the vegetative conditions of 

 that portion of Europe on this side of the Alps are present. Agriculture is 

 carried on there only as in gardens, at the chalets (Hatos) : potatoes and 

 barley, the latter usually only as high as 6300' ; at a single spot on the 

 southern slope as far as 7600'. There are no fixed dwellings; the land 

 is only used for pasturage, without, however, affording the same nourishment 

 to cattle as other mountains, for connected portions of meadow-turf are rare, 

 and even here shrubs and thorny plants cover the greater portion of the 

 slope. Formations of the Central European region : a. Shrubs of Sarothamnus 

 scoparius, Genista ramosissima, and Quercus Toza, ascending to 6000' ; at the 

 chalets, these are replaced by thickets of Rosa canina and Berberis vul- 



