504 REPLACEMENT OF THE ANCIENT E. AFRICAN FOREST 



slower than one would perhaps gather from the above account, 

 and the forest may even hold its own completely along consider- 

 able fronts for very many years. exj)laining the fact that in some 

 places the " Sand-apple line " even now nearly touches Chirinda, 

 and conveying- sometimes, to the mere traveller or short-term 

 resident, the impression that " the i)atches of dense-crowded 

 forest trees . . . are seldom or never affected by the annual 

 bush-fires "(S. A. Neave, " Zoological Collections from Northern 

 Rhodesia," P.Z.S., June, 1910). But in a dry year the fire runs in 

 further, and a succession of two or three dry years tends to 

 produce the result descrilied ])y W'hyte. It is f|uite interesting 

 that the destruction of jjortions of the Chipete and Chipungam- 

 bira forests already referred to should, according to my infor- 

 mant, have coincided with " the last great famine " — in, I should 

 judge from my estimate of his age, abotit 1S60. 



Other factors: Ciiltivatioti. — I have laid stress on fire be- 

 cause there is very clear evidence of its destructiveness in the 

 recent past, and because it is the only important factor that can 

 be seen at work here to-day. But another factor of possibly 

 high importance mtist by no means l)e lost sight of. I have stig- 

 gested (Journ. Linn. Soc. Bot. xl. ) that the grass-fires "obtained 

 their original hold on the forest-lands during some j^eriod of 

 dense native population.'" With a better realization of the time 

 re(|uired, T would no lonti'er say " original " ; but clearing for 

 cultivation, which was in m\ nnnd as affording starting-point? 

 for fire, may itself have contri])uted to the destrtiction. It is 

 very interesting to read Thomas Belt's account of the way in 

 which the whole Pacific slope of Nicaragtia has been, ai)parently. 

 cleared thus by the Indians -without the aid of fire* in the course 

 (he believes) of thousands of years, the trouble of weeding the 

 grass that soon comes in being in this case the incentive for the 

 continued use of the forests to the neglect of the still fertile 

 savannahs ; and Roosevelt records the destruction of much dense 

 forest in East Africa l^etween the Aberdare Range and Mount 

 Kenia " by the Kikuyu tribe in order to give them new soil for 

 cultivation," while " similarly destructive agricultural methods 

 have separated portions of the Elgon and Nandi forests, which 

 were formerlv continuous." ]\Tiss Lilian Gibbs, in a most in- 

 teresting paper describing the last of her adventurous explora 

 tions {Jour. Linn. Soc, 1914, xlii., no. 285). shows us a relatively 

 early stage ; for she describes how the primary forest of Borneo 

 still co\'ers the lowlands north oif Kinabalu, where there are no 

 natives, but has elsewhere been destroyed l)y them for ctdti- 

 vation up to an altitude of 3.500-6,000 feet, and, in the valleys, 

 considerably higher (p. 11). 



The clearing of this ty])e of forest is not the rule amongst 

 our natives to-day — I have seen only one small instance of it, 

 in Portuguese territory — but when Chirinda-like forest covered 

 a large projwrtion elf the country, there was more temptation 



=' Belt does not mention fire. 



