12 COLONIAL REPORTS MISCELLANEOUS. 



eight years, viz., 1892 to 1899, is 49'92 inches with maximum and 

 minimum respectively of 6b''74 and 40'64 inches, as against an 

 average of 43'34 inches and maximum and minimum of 50'53 

 ;uid 32'09 inches respectively for the second period of eight 

 years, viz., 1900 to 1907. 



Thus the average decrease has during this latter period been 

 at the rate of approximately inch per annum, a very high rate 

 indeed, and one which explains the invasion of the outlying hills 

 bordering the plains by deciduous-leaved species. 



The change from evergreen vegetation to that of the deciduous 

 lype means forest fires, and the latter in their turn mean the 

 dominance of grasses at the expense of tree vegetation. 



BOTANICAL GARDENS. 



My stay at Aburi gave me an opportunity of examining the 

 Botanical Gardens at that station and appreciating the large 

 amount of useful work th'at has been carried out there in a quiet 

 and unostentatious manner. In addition to the various plots 

 planted up with species of agricultural importance, special 

 attention has been paid to collecting and growing a representa- 

 tive series of the rubber and latex-yielding plants of tropical 

 countries, more particularly those from West Africa. 



The genus Ficus is well represented and the collection con- 

 tains, amongst others, quite a large number of specimens oi Ficus 

 elastica and Ficus Vogelii. I am informed that the yield of 

 rubber from the former has been very disappointing and nothing 

 like as abundant as that obtained from the latter. Moreover, 

 the rubber from this species as grown in the gardens appears to 

 contain a higher percentage of resins than does the correspond- 

 ing 1 product from trees grown in the East. The rubber from 

 F. Vogelii sells in the home markets at the rate of 25. per pound, 

 whilst that of the Ire or silk rubber tree, Funtumia elastica, 

 commands only 6d. a pound more in price. It is evident then 

 that F. Vogelii is quite a valuable rubber producer and its cult- 

 ivation on a large scale is worth undertaking ; it is of importance 

 to note that it is a native of the country and not an exotic. 



A fairly large plot has been planted with Castittoa elastica; 

 but without exception every tree has been seriously attacked by 

 a borer, and some of them even killed outright by the damage 

 done to them. This excellent rubber yielder appears to suffer 

 from similar attacks wherever it has been planted in Southern 

 Nigeria. In the Botanical Gardens at Calabar, however, the 

 damage done is very much less, and one or two good healthy- 

 looking trees that have escaped from their attacks are to be 

 found there. In the Olokemeji and Ebuta Metta Gardens of the 

 Western Province (Lagos) the species has been practically exter- 

 minated by these insects. It may be that the comparatively poor 

 rainfall of the Aburi and the two last-mentioned Gardens has 

 something to do with the extent of the damage and the preva- 

 lence of such attacks. 



Experiments are being carried out in the cultivation of one 

 of the numerous species of Ceara rubber trees, viz., Manikot 



