BOTANICAL GEOGRAPHY. 437 



leria and Poa laxa. Associated with these between 10,000' and 9000' we find 

 50 more, and as far as 8500', i. e. at the snow-line, 46 others; so that the 

 entire flora of the Rhetian Alps consists of 106 Phanerogamia, belonging to 

 23 families. All these plants are perennials, most of them casspitose, 

 hence they are propagated without the seed arriving at maturity ; all of them 

 are depressed and small, and are thus less influenced by the heat of the air 

 than of the soil : in fact, the only two woody plants are dwarf willows, their 

 stems being almost entirely inserted into the earth. Yet the temperature 

 of the soil at these altitudes is probably for a short time only above the 

 freezing point. The author very correctly explains their being enabled to 

 grow, notwithstanding this circumstance, by the short period of their vege- 

 tation, as when transplanted into the low. country, they become, without 

 exception, spring plants, which, in a few weeks after budding, ripen their 

 fruit, their winter sleep being proportionately prolonged. Moreover, in the 

 low country they all exhibit but little susceptibility to cold, so that even at 

 the period of their flowering, although exposed to frost, they are not at all 

 injured. Even if, in their elevated position, the spring season should not occur, 

 they would endure a state of hybernation for several years, without being 

 destroyed. The conditions of vegetation being so different from those of the 

 level country, explains the fact that the Phanerogamia of the snow-region 

 never become spontaneously distributed in the valleys. The case is different 

 with the Cryptogamia ; for the lower the degree of organization, says Heer, 

 the less does the form require to be modified, to adapt it to a different 

 climate. 



Mougeot and Nestler have published, in connexion with 

 W. P. Schimper, the twelfth century of their well-known 

 collection of dried Cryptogamia from the Vosges (Stirpes 

 Cryptogamae Vogeso-Rhenanae, fasc. 12. Bruyere, 1844, 

 4 to). 



French local floras and systematic contributions upon 

 French plants : Observations sur quelques Plantes Lor- 

 raines par Godron (Nancy, 1835, 8vo, pp. 31), con- 

 taining a supplement to his Flora of Lorraine; Choulette, 

 Synopsis de la Flore de Lorraine et d'Alsace, Partie i, 

 Tableau Analytiques (Strasb., 1845, 16mo); Cosson et 

 Germain, Flore descriptive et analytique des Environs de 

 Paris (Paris,1845, 8vo, 2 vols.), remarkable for its accuracy, 

 and the systematic investigations contained in it ; it gives 

 satisfactory elucidations, e. g. of Astrocarpm Clusii, Tri- 

 folium Parisicme, Euphrasia Jaubertiana, Potamogeton 

 tuber culatus, tmdCarevMairii; Puol, Catalogue des Plantes 



