13 CINCHONA BARKS. 
Muts, and also possibly in part in C. hirsuta, C. Mutisii, and C. 
pubescens) ; they are smooth, or at the most slightly revolute, 
always entire, and besides often very variable on the same tree, 
(as, e. g.,in C. heterophylla). With regard to size, the leaves also 
vary considerably. Occasionally the young leaves are of a purple 
or purplish-violet color (in Spanish morado) on the under surface ; 
and the fully developed leaves of several species assume quite 
regularly, directly before falling, this often very rich, dark color, 
which is strongly marked, e. g. in C. purpurescens, Wedd. 
The Cinchonas present themselves as handsome, even though 
not precisely extraordinarily remarkable, shrubs or trees of the 
tropical primeval forest, of about the appearance of the Syringa. 
The genus Cinchona is one so uniform, and whose members 
agree so closely, that a satisfactory definition of the latter is not 
readily accomplished. The individual species are connected with 
each other by intermediate forms, and form a continuous series, 
the terminal members of which are moreover scarcely more sharply 
separated from the above-mentioned allied genera than from 
plants of their own series. In the systematic botany of the Cin- 
chonas the limit of the species is therefore often dependent upon 
very insignificant characters, for the justification of which doubt 
prevails in many cases. According to the diversity of view in the 
conception of the species, the number of species of cinchona 
accepted by botanists has consequently varied. In the year 1830, 
for example, the Prodromus of De Candolla accepted 18 species. 
Howard’s handsome work, ‘“ Nueva Quinologia,” contains 38 species, 
which are represented also for the most part by figures; but which 
on the one hand must be considerably increased, and, on the other, 
modified by the combination of evident sub-species. | Without 
consideration of the fact that some botanists have connected plants 
with the genus Cinchona, which, according to the above outlined 
diagnosis of the genus (page 10), are positively distinct therefrom, 
the number of good species of Cinchona which has been gradually 
described has increased to about 50. A complete review of the same 
is given in Weddell’s “ Notes sur les Quinquinas,” where indeed 
33. species’ are still represented, while 18 others are mentioned 
only as sub-species, with varieties and sub-varieties. According to 
Weddell’s representation there is, however, also in those species no 
1 Figures in Histoire naturelle d2s Quinguinas, 17, by Weddell ; Flor. Columb. I, tab. 
VIII, by Karsten; and in Medicinal Plants by Bentley and Trimen, London, 1880, 143. 
* Enumerated in Pharmacographia by Fliickiger and Hanbury, 1879, p. 355, with the 
yeni an of Cinchona Chomeliana and C. barbacéensis, whtehomtint be Si ecnent from 
Cinchona. | ee 
