GEOGRAPHICAL BOTANY. 319 



on the frequent use of this chart, very numerous. 

 Moreover, many of the sheets intended to illustrate 

 meteorological relations appear indispensable also to the 

 botanist. 



M. Romerhas commenced the publication of a Memoir 

 entitled ' Botanical Geography and Geographical Botany/ 

 which treats of the subdivision of the surface of the earth 

 into natural Floras. (Liidde Zeitschr. fur vergl. Erdkunde, 

 Bd. iii, pp. 527-534.) 



A paper by E. Fries, entitled " The Native Land 

 of Plants," in his peculiar style, the special interest of 

 which is confined to the Swedish public, but also fre- 

 quently touches acutely more general questions, treats of 

 different botanico-geographical subjects, especially of the 

 native country of the so-called ruderal plants. (Botaniska 

 Utflygta, Bd. i, pp. 229-328, translated in Hornschuch's 

 Archiv Skandinav. Beitrage zur Naturgesch. Bd. i, 

 H. 3.) The original native country of many cultivated 

 plants cannot now be determined by empirical proof, but 

 only by rational investigation. Thus rape is no longer 

 met with in its wild state, but when we adduce proof 

 from all extra-European countries that it is not indigenous 

 to them, we must conclude that it is of European 

 origin, although its wild state has disappeared through 

 cultivation. Many plants have been extirpated by use ; 

 this is now gradually taking place with Gentiana lutea, 

 in the Alps, and Inula Helenium in the west of Sweden. 

 The contact of Nature with man exerts no less a modify- 

 ing influence upon the vegetable kingdom than upon the 

 animal creation. The original vegetation of a country 

 must in general, therefore, be regarded as more rich in 

 species, and in this manner in Sweden and Germany, 

 even under our own eyes, the localities of rare plants are 

 disappearing one after the other, as e. g. of Trapa, Xan- 

 thium, and Stipa. 



