GEOGRAPHICAL DISTRIBUTION OP PLANTS. 



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siyely lose the oak, the hazel, the ash, the lime 

 tree, the Scotch fir, the spruce fir, and the Si- 

 berian cedar; while the larch extends to the 

 shores of the Arctic ocean. In the southern 

 parts of Siberia are found wild tulips, anemones, 

 two species of rhododendron, and the scarlet 

 Ij'chnis. To the east of lake Baikal, the Euro- 

 pean globe flower is replaced by the Asiatic 

 species. In Siberia also grow the cranberry and 

 the hautboy strawberry. 



The oak, the beech, and the elm are natives 

 of Great Britain. Each of these trees has its 

 appropriate soil. In the western part of the 

 county of Sussex,,we have three distinct belts 

 of country, each strongly marked by the char- 

 acter of its vegetation. To the north we have 

 a strong and deep clay, admirably adapted to 

 the growth of oak. Then come the chalk hills, 

 where the luxuriant growth of the beech attests 

 that this tree has found its congenial soil. This 

 tree is not met with north of Stamford in Lin- 

 colnshire. The elm seen in Scotland and the 

 north of England is the vifych elm, a different 

 species, growing m a more straggling form, with 

 pendent branches, and a larger leaf. Its wood 

 is very imlike that of the English elm; more 

 resembling that of the ash. In the approach 

 to some of the royal palaces in Spain, are some 

 rows of elm, which, we are assured by Evelyn, 

 were transplanted from England by Philip II., 

 the husband of queen Mary of England, the 

 elm not being a native of Spain. In addition 

 to the trees just mentioned, the ash, the maple, 

 the sycamore, and the small-leaved lime tree, 

 may be enumerated as growing vrild in Great 

 Britain. 



If we now turn our attention to the countries 

 occupying the southern side of the Baltic, we 

 shall find a wide district oilteath, beginning from 

 the northern extremity of Jutland, extending as 

 far south as latitude 62° ; thence westward as 

 far as the ocean, and eastward over a considerable 

 part of the north of Germany. In this barren 

 tract, the few spots which have teen brought 

 into cultivation by human industry appear like 

 green islands amidst the waste. The variety of 

 species of heath found in this tract is very small; 

 and few, if any of them, are strikingly beautiful. 

 In the wet and springy parts of the district are 

 many tracts of bog, or peat moss, scarcely less 

 sterile than heath. Occasionally, however, the 

 cranberry, and some other eatable berries of the 

 same family, as the Wherry and the whortleberry, 

 cover the surface ; and the substance of the bog 

 itself furnishes a kind of fuel to the poor inhabi- 

 tants, after being cut in small square pieces, and 

 piled in stacks to dry. When attentively ex- 

 amined, it is found to consist of vegetable fibres, 

 partially decayed, and compacted by the pres- 

 sure of the superincumbent portion. Its com- 

 position is only to be seen, however, in that part 



of the bog which lies toward the surface; towards 

 the bottom it takes the appearance of a black 

 and solid mass. In many places the natural soil 

 is covered to a depth of twenty or thirty feet 

 with this substance. The plants by whose de- 

 composition these bogs are formed, appear to be 

 principally two or three kinds of moss. These 

 are almost invariably found growing on the sur- 

 face ; and it appears that each generation, as it 

 dies, forms a soil for that which is to succeed. 

 That a continual growth really takes place, is 

 proved by the gradual filling up of the hollows 

 excavated for obtaining fuel. Much of the sur- 

 face of Scotland, the north of England, Wales, 

 and Ireland, is covered with these bogs, as well 

 as of that part of the continent of Europe which 

 touches the shores of the German ocean and the 

 Baltic. 



To the south of this barren tract of heatt and 

 peat moss, we find an extensive region of re- 

 markable fertility, in which every species of our 

 cultivated grain flourishes. This district, which 

 is for the most part unbroken by hills of any 

 considerable height, comprises the Netherlands, 

 the greater part of France, the middle of Ger- 

 many, Poland, and southern Russia. The east- 

 em part of this region being comparatively thinly 

 peopled, supplies with corn several other parts of 

 Europe; the produce of the soil oeing carried 

 down by internal navigation, partly to the porta 

 on the Baltic, partly to those on the Black sea. 



The line which limits the cultivation of corn, 

 like that which limits the growth of the oak and 

 other forest trees, extends much further north 

 on the western side, than on the eastern side of 

 the continent. In Norway, barley sometimes 

 ripens, in favourable aspects, under the 70th par- 

 allel of latitude. In European Russia, the cul- 

 tivation of com scarcely succeeds beyond lati- 

 tude 60°; and in Kamschatka, the eastern extre- 

 mity of Asia, this limit descends as low as 61°, 

 the latitude of London. On the eastern shore of 

 the continent of America, the growth of corn 

 does not extend beyond latitude 62°. Wheat 

 demands a warmer climate than barley or oats. 

 This grain is not found to succeed so weU in the 

 west of Scotland, the summer's sun being insuf- 

 ficient to ripen it. Even in England, the west- 

 em side of the island appears better adapted to 

 the growth of grass than of com ; and accord- 

 ingly, it may be observed, in every part of the 

 kingdom, that com is carried from east to west, 

 while cattle are driven from west to east. All 

 our principal com counties are situated on the 

 eastern side of the island, from the Lothians, in 

 Scotland, to Kent, the south-eastern county of 

 England. This is to be attributed, in a great 

 measure, to the humidity of the climate in those 

 districts bordering on the sliores of the Atlantic. 



The cultivation of com does not succeed better 

 in the torrid zone than in the polar recricns. 



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