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jif^haniiion, 

 PUira. 



The Burmese Flora is a part of the Eastern or Further Indian Flora, of which the 

 Khasya hills form the extremest North-west, and Siam and Cochin-china the extreniest East 

 and South-east parts. It may be divided into several tracts, such as the Arracan Yomah, 

 Pegu Yomah, the Martaban or Karen hills, and finally into the Tenasserim and Ava tracts. 

 Each of these tracts has its peculiarities, which, however, I do not consider it necessary to 

 elucidate here. 



Before treating of the zones of Pegu, we must distinguish, first, general or geographical, 

 and, second, special or local zones. 



Botanically we usually distinguish the following general zones on the Northern (and 

 alfio Southern) hemisphere of our globe, which nearly agree with the geographical ones, viz : 



1. The equatorial zone, from the equator to North Lat. 15. 



2. The tropical zone, from North Lat. 15 to 23. 



3. The subtropical zone, from North Lat. 23 to 34. 



4. The warmer temperate zone, from N orth Lat. 34 to 45. 



5. The colder temperate zone, from North Lat, 45 to 58. 



6. The subarctic zone, from 58 to 66. 



7. The arctic zone, from 66 to 72, and 



8. The polar zone, from 72 to the pole. 



For these somewhat too artificial zones, founded chiefly on the yearly means of temperature, 

 I wish to substitute the following revised scheme :* 



I. The warm zone {Thermozone), from the equator to 35 North Lat. The seasons of 

 the year are either little marked, or are more usually divided into a dry and rainy season. The 

 thermometer very seldom sinks below freezing-point and then only along its borders in contact 

 with the wintry zone. There is almost no difl'erence between day and night under the equator, 

 but it varies gradually towards the northern borders of the zone from a fraction of an hour 

 to about 4 hours. It is divided into : 



1. A tropical subzone, from the equator to the tropic of Cancer, and 



2. A subtropical subzone, from the tropic of Cancer (285) to 35 North Lat. 



Each of these subzoues must again carefully be distinguished into such tracts as have 

 a moist climate (hygroclimatic tracts), and such as are more or less destitute of rains (Xero- 

 climatic tracts), such as the African and Asiatic deserts. 



II. The wintry zone {Chcimnzone), from 35 North Lat. to the arctic circle, (66|). 

 The seasons of the year consist of a winter and a summer, with spring and autumn. During 

 winter there is freezing and a more or less regular fall of snow. Here the days and nights are 

 still distinct, but the difference between day and night varies from 5 to 24 hours. There ai-e two 

 divisions of this zone, r^iz : 



1. A subtemperate subzone, from 35 to 45 North Lat. and 



2. A temperate subzone, from 45 North Lat. to the arctic circle. 



III. The polar or frigid zone (Polozone), from the arctic circle to the pole. Summers are 

 of very short duration, winters very long and rigorous, and, towards the poles, eternal. There 

 is no daily difference betwtcn day and night, but a long day from two to more than six months 

 duration, altcrijating with a jiight of a similar length, during which only mysterious lights, 

 such as the aurora borea/is, jircseut a substitute for the sun. The two subzones are : 



In doing so it will be oli.'^crvcd tliat 1 have abandoned the old-fashioned notions of botanists regarding 

 " temperate forms." This, however, is not the proper place to discuss the reasons ofuiy views. 



