2o8 Woodhead : Plant Geography in Switzerland. 



on the Camoghe gruppe. These phy to-geographical and ecolo- 

 gical studies are fostered by, and largely the outcome of the 

 National Agricultural School, and they never lose sight of the 

 fact that the problems involved are really agricultural and 

 forestry problems. 



Aliens have always been an unsatisfactory element to deal 

 with, but Rikli and Nageli and Thellung have made a fairly 

 satisfactory attempt to deal with them according to their modes 

 of origin.* The names suggested for the groups, however, are 

 too unwieldy ever to come into general use. 



Swiss Survey Maps are pubhshed in two scales : — [a) for 

 the plains, i : 25,000, (6), for the Alps, i : 50,000. They shew 

 clearly and exactly the following features as regards vegetation : 

 (i) Region of vine cultivation ; (2) Pastures and meadows, 

 (3) Moors ; (4) Moors cut for peat ; (5) Forests ; (6) Rocky 

 slopes (Felsenheide) ; (7) Alpine region ; (8) Snow and Ice . 

 These maps are perhaps the most beautiful in existence, and 

 we must admit, that from a vegetation point of view, they are 

 a great advance on our own, and the details we are shewing 

 on our vegetation maps are already published to a considerable 

 extent by the Swiss survey. It is very important to keep this 

 fact in mind when considering their plant-geography papers. 

 No distinction, however, is drawn between coniferous and 

 deciduous forests, while Finns montana, usually regarded as a 

 shrub in plant-geography maps, is here included in the forest 

 region, a detail doubtless influenced by military considerations. 

 It has been the object of some of the works referred to [e.g. 

 Geiger, Bettelini, Brunies, etc.) to study in detail the distribu- 

 tion of the several species of trees, and bring out the main 

 factors affecting their distribution. Imhof,t a pupil of Briickner, 

 has published an excellent study on the limits of forest in 

 Switzerland, based upon the survey maps. 



Ecological Studies of the Cryptogamic Flora. — Cryp- 

 togamic Ecology (apart from plankton), has received consider- 

 able attention. So early as 1871 (F. H., 64), Pfeffer published 

 especially interesting observations on the Bryogeography of 

 the Rhoetic Alps, noting the effects of altitude, subsoil, and the 

 like on the distribution of the several species. 



Amann (1894, F. H.,.59), studied the moss flora of the 

 erratic blocks of the Swiss ' Hochebene ' and the Jura, and shews 



* See ' Naturalist,' 1906, p. 124. 



t E. Imhof, ' Die Waldgrenze in der Schweiz. Leipzig,' 1901. 



Naturalist, 



