Book T 



DISTRIBUTION OF VEGETABLES. 



R. Brown {Gen. Re7n on the Bot. of Terr. Aust., 1814.), from Persoon's Sytiopsis, to be 

 to the Dicotyledoneae as 2 to 11; or, with the addition of undescribed plants, as 2 to 9. 

 From the equator to 30 of north latitude, they are as 1 to 5. In the higher latitudes a 

 gradual diminution of Dicotyledoneae takes place, until in about 60 north latitude and 

 50 south latitude they scarcely equal half their intertropical proportions. The ferns in 

 the temperate regions are to the whole number of species as 1 , 2, and 5 ; that is, in the 

 polar regions as 1, in the temperate countries as 2, and in the intertropical regions as 5. 

 In France, ferns form ^ pait of the phanerogamous plants ; in Germany, ^*g ; in Lap- 

 land 2V 



1781. The natural orders of perfect, or phanerogamous, plants are variously dis- 

 tributed in different countries. The following Table gives a general view of the relative 

 proportions of several natural orders of perfect plants in France, Germany, and Lapland. 



1782. The most universal plants are the agamous 

 families. Their germs are the only ones which nature 

 developes spontaneously in all climates. The Poly- 

 trichum commune (Jig. 202. ) grows in all latitudes ; 

 in Europe and under the equator; on high mountains 

 and on a level with the sea; in short, wherever there 

 is shade and humidity. No phanerogamous plants have 

 organs sufficiently flexible to accomodate themselves in 

 this manner to every zone. The ^Isine media, Fra- 

 garia v^sca, and 5'olanum nigrum have been supposed to 

 enjoy this advantage ; but all that can be said is, that 

 these plants are very much spread, like the people of the 

 race of Caucasus, in the northern part of the ancient con- 

 tinent. ( Humboldt. ) 



Sect. VI. Economical Distribution of Vegetables. 



1783. The plants chiejlij employed in human economy differ iii different climates and 

 counties ; but some, as the cereal grasses, are in universal use ; and others, as the banana 

 and plantain, only in the countries which produce them. 



1784. The bread-corn of the temperate climates is chiefly wheat and maize ; of the hot 

 climates, rice, and of the coldest climates, barley. 



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