CORTEX CINCHONiE. 339 



The fruit is a capsule of ovoid or subcylindrical form, dehiscing from 

 the base (the fruitstalk also splitting) into two valves, which are held 

 together at the apex by the thick permanent calyx. The seeds, 30 to 

 40 in number, are imbricated vertically ; they are fiat, winged all round 

 by a broad membrane, which is very irregularly toothed or lacerated at 

 the edge. 



The Cinchonas are evergreen, with finely-veined leaves, traversed 

 by a strong midrib. The thick leafstalk, often of a fine red, is sometimes 

 a sixth the length of the whole leaf, but usually shorter. The leaves 

 are ovate, obovate, or nearly circular ; in some species lanceolate, rarely 

 cordate, always entire, glabrous or more rarely hirsute, often variable as 

 to size and form in the same species. 



Among the valuable species, several are distinguished by small pits 

 called scrobiculi, situated on the under side of the leaf, in the axils of 

 the veins which proceed from the midrib. These pits sometimes exude 

 an astringent juice. In some species they are replaced by tufts of hair. 

 The young leaves are sometimes purplish on the under side ; in several 

 species the full-grown foliage assumes before falling, rich tints of crimson 

 or orange. 



The species of Cinchona are so much alike that their definition is a 

 matter of the utmost difficulty, and only to be accomplished by resort- 

 ing to a number of characters which taken singly are of no great 

 importance. Individual species are moreover frequently connected 

 together by well-marked and permanent intermediate forms, so that 

 according to the expression of Howard, the whole form a continuous 

 series, the terminal members of which are scarcely more sharply 

 separated from the allied genera, than from plants of their own series. 



As to the number and value of the species known, there is some 

 diversity of view. Weddell, in 1870, enumerated 33 species and 18 

 sub-species, besides numerous varieties and sub- varieties. Bentham and 

 Hooker, in 1873, estimated the species as about 36. 



Kuntze, in the book quoted at the end of the present article, pro- 

 posed to reduce all the species to the four following : 



1. Cinchona Weddelliana O. Kuntze, nearly answering to G. 

 Calisaya Weddell. 



2. C. Pavoniana O. Kuntze, including G. micrantha Kuiz and 

 Pavon and several allied plants. 



3. C. Hoiuardiana O. Kuntze, constituted of G. succiruhra Pavon 

 and a few other species of former authors. 



4. G. Pahudiana Howard. 



Kuntze, who has examined the living Cinchona as cultivated in 

 India, is of the opinion that all the numerous forms hitherto observed, 

 both in the wild plants and in cultivation, are merely either belonging 

 to the above four species or deriving from them chiefly by hybridation. 

 Though much in favour of a reduction of the species, we are not yet 

 prepared to accept Kuntze's arrangement. 



(B.) Area, Glimate and Soil. — The Cinchonas are natives of South 

 America, where they occur exclusively on the western side of the conti- 

 nent between 10° N. lat. and 22° S. lat., an area which includes portions 

 of Venezuela, New Granada, Ecuador, Peru, and Bolivia. 



The plants are found in the mountain regions, no species whatever 



