INTEODUCTORY 21 



minate. This necessitates their exposure througliout one 

 hot season, when the whole of the grass covering the ground 

 below is burnt in the annual conflagrations. Thus a large 

 percentage of the seeds of the Teak never germinate at all. 

 It is clear, then, that if these two species were growing 

 together, on soil equally suitable for both, the Sal must 

 possess an immense advantage in the " struggle for life " 

 over the Teak. And if to this natural advantage be added 

 an adventitious one, in the fact that the Teak is much 

 more generally useful to man — ^particularly to man in a 

 primitive state — as is really the case, there seems to be 

 a suflB.cient reason why the Teak should disappear before 

 its rival in tracts where the latter has obtained a footing 

 and is equally suitable to the soil and cUmate. Now an 

 examination of the tracts on which these trees are found 

 in Central India shows that, while the Teak does not appear 

 to shim any particular geological formation, it thrives 

 best on the trap soils which predominate in the south and 

 west of the province. But the Sal, on the other hand, 

 clearly shuns the trap formation altogether. Not only 

 is it unknown within the great trappean area to the west 

 of the eightieth degree of longitude, but even to the east 

 of that line, in its own peculiar region, it does not grow 

 where isolated areas of the trap rocks are foimd. Further, 

 I believe that in no part of India where this tree grows is 

 there any of the trap formation. With the exception only 

 of this volcanic rock, the Sal appears to thrive on any 

 other formation, being equally abundant within its own 

 area, where primitive rocks, or sandstones, or lateritic 

 beds predominate. Thus I beheve that the Sal, where 

 the soil is suitable — ^that is, where there are no trap rocks 

 — has exterminated the Teak, of which it is a natural 

 rival. In other parts of India, where the Teak does not 

 meet with this rival, as in Malabar and Burma, it flourishes 

 on the soils from which it is here excluded by the Sal. 

 The general conclusion appears irresistible, but sharp 

 contrasts perhaps best illustrate such peculiarities. Many 

 such might be mentioned, but two in particular are very 

 noticeable. Within the Sal region, in the hills immediately 

 to the east of the town of Mandla, there is a considerable 



