Naturalisation in Extra-Tropical Countries. 115 



natural Cinchona-regions to fluctuate between 35 and 60 F. We 

 here ought to consociate the Peru-bark plants with naturally 

 growing fern-trees, but only in the warmest valleys and richest 

 soil. The best temperature for Cinchonas is from 53 to 66 F.; 

 but for the most part they will endure in open places a minimum 

 of 32 F.; in the brush-shades of the Botanic Garden of Melbourne, 

 where already many years ago Cinchonas were raised by the 

 thousands, they have even resisted uninjured a temperature of a 

 few degrees less, wherever the wind had no access, while under 

 such very slight cover the Cinchonas withstood also a heat of a few 

 degrees over 100 F. 



The plants are most easily raised from, seed, best under some 

 cover such as mats ; they produce seeds copiously some years after 

 planting. C. succirubra, first introduced into California by the 

 writer of this work together with the principal other species, 

 thrives well in the lower coast-ranges as far north as San Francisco ; 

 better indeed than C. Calisaya, according to Dr. Herman Behr. 

 The quantity of alkaloids in the bark can be much increased by 

 artificial treatment, if the bark is only removed to about one-third 

 on one side of the stem and the denuded part covered with moss 

 or straw-matting (kept moist), under which in one year as much 

 bark is formed as otherwise requires three years' growth such 

 forced bark moreover containing the astounding quantity of 25 per 

 cent, alkaloids, because no loss of these precious substances takes 

 place by gradual disintegration through age. The root-bark of 

 some Cinchonas has proved to contain as much as 8 per cent, 

 of alkaloids (see Gardeners' Chronicle, 1877, p. 212). The income 

 from Java-plantations is considerably over double the cost of the 

 expenses of culture and transit. Mr. Howard's opinion, that 

 Cinchonas in lowland-plantations produce a far less quantity of 

 alkaloids, needs further confirmation, particularly regarding the 

 valuable quinin and cinchonidin ; probably however geologic con- 

 ditions have in all instances to be taken into account also. 



Young Cinchona-plants are set out at distances of about 6 feet. 

 The harvest of bark begins in the fourth or fifth year. The price 

 varies in Europe from 2s. to 9s. per Ib. according to quality. The 

 limits assigned to this literary compilation do not admit of entering 

 further into details on this occasion ; but I may add, that in the 

 Darjeeling-district over three millions of Cinchona-plants were 

 already in cultivation during 1869 in Government-plantations, 

 Cultivation of Cinchona for commercial purposes was first initiated 

 in Java through Dr. Hasskarl in 1851 ; but 240,000 Ibs. of bark 

 were already exported from this island in 1880. The British 

 harvest in the Madras-Presidency alone amounted to 150,000 Ibs. 

 in 1875. Brigade- Surgeon Dr. G. King reports in 1880, that four 

 million trees of Cinchona succirubra are now under his control in 

 the Skkim-plantations. This has proved the hardiest species ; it 

 grows under a wide range of conditions and seeds freely ; thus it 



H2 



