340 RUBIACEiE. 



being known to inhabit the low alluvial plains. In Peru and Bolivia, 

 the region of the Cinchona forms a belt, 1300 miles in length, occupying 

 the eastern slope of the Cordillera of the Andes.^ In Ecuador and 

 New Granada, the tree is not strictly limited to the eastern slopes, but 

 occurs on other of the Andine ranges. 



The average altitude of the cinchoniferous region is given by Wed- 

 dell as 5,000 to 8,000 feet above the sea-level. The highest limit, as 

 noted by Karsten, is 11,000 feet. One valuable species, G. succirubra, 

 occurs exceptionally as low as 2,600 feet. Generally, it may be said 

 that the altitude of the Cinchona zone decreases in proportion as it 

 recedes from the equator, and that the most valuable sorts are not found 

 lower than 5,000 feet. 



The climate of the tropical mountain regions in which the Cinchonas 

 Nourish, is extremely variable, — sunshine, showers, storms, and thick 

 mist, alternating in rapid succession, yet with no very great range of 

 temperature. A transient depression of the thermometer even to the 

 freezing point, and not unfrequent hail-showers, may be borne without 

 detriment by the more hardy species. Yet the mean temperature most 

 favourable for the generality of species, appears to be 12 to 20° C. 

 (54 to 68° F.) 



Climatic agencies appear to influence the growth of Cinchona far 

 more than the composition of the soil. Though the tree occurs in a 

 gi'eat variety of geological formations, there is no distinct evidence that 

 these conditions control in any marked manner either the development 

 of the tree or the chemical constitution of its bark. Manure on the 

 other hand, though not increasing perceptibly luxuriance of growth, has 

 a decided effect in augmenting the richness of the bark in alkaloids.^ 



(C.) Species yielding oficinal barks. — The Cinchona Barks of com- 

 merce are produced by about a dozen species ; of these barks the 

 greater number are consumed solely in the manufacture of quinine. 

 Those admitted for pharmaceutical use are afforded by the following 

 species: — 



1. Cinchona officinalis Hooker ^ — A native of Ecuador and Peru, 

 existing under several varieties. It forms a large tree, having lanceolate 

 or ovate leaves, usually pointed, glabrous, and shining on the upper sur- 

 face, and scrobiculate on the under. The flowers are small, pubescent 

 and in short lax panicles, and are succeeded by oblong or lanceolate 

 capsules, | an inch or more in length. 



2. C. Calisaya Weddell — Discovered by Weddell in 1847,^ although 

 its bark had been an object of commerce since the latter half of the 

 previous century. 



The tree inhabits the warmest woods of the declivities which border 

 the valleys of Bolivia and South-eastern Peru, at an altitude of 5000 to 

 6000 feet above the sea-level. More precisely, the chief localities for 

 the tree are the Bolivian provinces of Enquisivi, Yungas de la Paz, 

 Larecaja or Sorata, Caupolican or Apolobamba, and Mufiecas : thence it 



^ That is to say the eastern Cordillera, the ^ Figured in Bot. Magazine, vol. 89 (1863) 



western and lower range being called the tab. 5364, including C. Condaminea Humb. 



Cordillera of the Coast ; no Cinchonas grow et Bonpl. and C. Uritusinga Pavon. 



on the latter. * Ann. des Sciences not., Bot. x. (1848) 6, 



- Broughton, in Pharm. Jmirn. Jan. 4, and Hist. nat. des Quinquinas, 1849, tab. 3, 



1873. 521. figured in Botanical Magazine, 1873. 6052, 



and 1879. 6434. 



