CHAP. VII. BOTANICAL GEOGRAPHY. 305 



they might lie under the same parallel of latitude, would 

 contain few species common to both. Such districts are 

 termed " botanical regions." These are spaces enclosing 

 particular species, distributed through them in the sta- 

 tions adapted to their growth ; but so encompassed by 

 physical obstructions, that the great majority of species 

 found within their limits are not to be met with else- 

 where. We do not as yet possess any very accurate 

 information respecting the number and exact extent of 

 the well-defined botanical regions into which the surface 

 of the earth may be mapped out. There are about 

 fifty whose floras have been partially examined, and of 

 which the following list has been given: 



1. Arctic. Includes the northern parts of Asia, 

 Europe, and America. This region is not well defined 

 towards the south ; but may be considered as termin- 

 ating in that direction between lat. 62 and 66. 



2. European. Included within a line drawn from 

 the north of Scotland, through St. Petersburg, the Ural 

 Mountains, to the north of the coasts of the Mediterranean 

 up to the Pyrenees. 



3. Mediterranean. Coasts all round the Medi- 

 terranean, with Italy, Dalmatia, Greece, Syria, and 

 Spain. 



4. Red Sea. Includes Egypt, Abyssinia, and part 

 of Arabia. 



5. Persian. Includes countries round the Per- 

 sian Gulf. 



6. Caucasian. Caucasian chain and countries 

 between the Euxine and Caspian. 



7. Tartarian. About Lake Aral. 



8. Siberian. Between the Northern Ocean and 

 the Ural Mountains. Bounded towards the south by 

 the Altaic Mountains. 



9. Nepaul. The chain of the Himalaya. 



10. Bengal. The plains through which the Ganges 

 flows. 



1 1 . Indian The Peninsula and Ceylon. 



