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will either perceive commanding ridges overtopping or sheltering the sides of a ohoung, where 

 he expected, according to exposure, a deciduous forest, or will discern the slopes of the ridges to 

 run at such a low angle, that the influence of exposure is entirely or partially annulled. Steady 

 hot winds blowing against a favourably exposed slope may also suppress (as is the case in the 

 dry hot Prome district) evergreen forests, and so again, a sterile impermeable rocky or pebbly 

 soil may produce a crooked and stunted vegetation even in the most favourable sites. For 

 every apparent exception in nature, there is an explanation ; and a forester, who has made 

 himself master of all the various factors which govern vegetation, will look no more upon the 

 extensive mass of forests tl.at spreads out before him as an unmanageable chaos of trees, but 

 will recognise, in all its intricacy, an order and wisdom, which must materially add to the 

 pleasures which an educated man can derive from nature. 



5. Influence of tcinds. Winds can influence vegetation in two different ways, viz. (1) 

 they can cause a drier or moister climate according to their general direction and to the 

 tracts over which they blow, or (2) they can influence the general growth of trees or prevent 

 their growth at all. The first named case belongs to climatology, and is already discussed 

 under 3. The winds that influence the growth of trees are chiefly the S. W. monsoon wiuds 

 which blow forcibly during the rains. In the northern latitudes of our globe they are 

 represented by the northern winds. Trees in exposed situations are, therefore, often bent 

 in conformity with these winds, or at least an eccentric growth of the annual rings can be 

 observed on the sections of trees thus exposed. But in higher regions, as for instance in the 

 Karen hills, these monsoon winds also cause the suppression of jungle growth. In such 

 localities we then find the so-called hill-pastures, on which few or no trees can support them- 

 selves. A crooking of the tops of the crowns of trees is also often the result of such 

 winds. 



6. Influence of jungle-fires. Jungle-fires are happily not often the object of consider- 

 ation with a botanist, but here in Burma they are so regular and so extensive as to become a 

 powerful prohibitive factor in vegetation. During the hot season here a botanist has to collect 

 his flowers enveloped in smoke and surrounded by fires in all directions. 



The full influence of jungle-fires will only duly be appreciated after the authorities 

 shall have succeeded in suppressing these destructive agencies, at least so far, that they 

 cease to be the rule and become only exceptions. Against the fire-raising propensities 

 of Burmans and Karens, the most energetic action of Government will hardly succeed, and 

 it will be very difficult to prevent these people from setting fire to their toungyas, to which 

 jungle-fires must be chiefly attributed. 



The jungle-fires may be divided into superficial and destructive ones ; the former affec- 

 ting only the low growth, the latter often destroying also trees and other woody plants. 



Superficial jungle-fires are annual ones, occurring more or less regularly every hot season, 

 sometimes twice over, and burning down the fallen leaves and the dried up grasses and iierbs. 

 Old half-rotten but dry logs are often consumed, healthy ones are rarely more than scorched 

 by the fires. Sometimes, but very rarely, the fires enter the outskirts of the evergreen forests, 

 burning up the dry fallen leaves, but doing little damage beyond scorching the undergrowth. 



The destructive jungle- fires do not occur annually,* but periodically. They set in after 

 the bamboo has come into flower. It is well known, that most of the bamboo species, which 

 often form such a dense undergrowth in the Burmese forests, flower rarely ; and that when 

 a species gets into.flower, all or nearly all individuals of the same locality flower simultaneously, 

 although the same species in other localities does not. Those few that do not flower the 

 same year, do so usually the following year, a confirmation of the presumption that they 

 are nothing but stragglers of the same stock. After flowering and fruiting they die off. 

 However the dying off is not rapid, but slow, sometimes taking two to three years. The 

 spikelets protrude one behind the other in such profusion, that it is no wonder that the 

 plants become exhausted. It is then, when the bamboo dies off and has become dry enough, 

 that the destructive jungle-fires commence. 



The quantity of seeds and seedlings burnt up upon such occasions must be astounding, 

 and the comparative scarcity of shrubs may also be attributed to these fires. Perennials and 

 half shrubs are usually burnt down to the ground. They develop leaves or flowers only after 

 the fires have rnged over them : whether this is attributable to a normal state of develop* 

 ment or to a forced inheritance, I cannot say. These young flowering shoots are often very 

 different looking from those that are thrown out at a later period, or from individuals that have 

 escaped injury. They resemble somewhat scapiferous plants, or, if branched, such plants as 

 are continuously browsed by cattle. 



However, the savannah fires, really fearful in certain respects, may occur annually. Tliey shew us what 

 ar\ amount of heat trees can resist, ibr although the bark is scorched and often enough burnt to coal, and the 

 foliage totally scorched, they recover again perfectly during the ensuing rainy season. The flames not seldom enve- 

 lope the whole lower part of the crown, especially if the grasses consist of Saccharum procerum and PhragmiUs. 



