VARIETIES OF CINCHONA BARK. 41 
SECTION IX. 
VARIETIES OF CINCHONA BARK. 
If the anatomical relations of the true Cinchona barks are sum- 
marized, it is manifest that they owe their peculiar character as well 
to the totality of the former as also particularly to the nature and 
position of their lignified bast-fibres. This appears very prominent 
in distinction to the other Cinchonee which are so closely connected 
in the system, the structure of which, however, has as yet only been 
described in a few instances.*. In many of the latter, the lacticife- 
rous ducts are much more perfectly developed, and the sclerenchyma 
forms likewise, even in the outer bark, large and often vertically 
extended bundles; the bast, however, deviates most from the above- 
described type of the Cinchonas, as has already been shown on 
page 38. The bast-fibres of many of the false Cinchonas are thin, 
by far not completely lignified, on a transverse section exhibiting a 
significant cavity, and usually roundish. On a longitudinal section 
they display considerable length, and as strong, often net-like, 
transversely connected fibres, impart to the entire tissue a coherence 
which the short, simple fibres of the Cinchonas are not able to give. 
In many of the false barks, the parenchyma of the bast also 
performs a more significant part, whether it be that its regularly 
arranged tangential zones, alternating with fibre-bundles, cause a 
reticulated appearance, or whether the inner half of the bast is built 
up, to a largely predominating extent, of parenchyma. The tissue 
of these barks also receives hereby far greater firmness and tenacity 
than the Cinchona barks. : 
These distinctions are then also perfectly adequate to discrimi- 
nate between the barks of the Cinchonas and those of the other 
allied genera. : eo | 
As in many barks, the transverse fracture of the Cinchona barks 
is also subjecg to variation in the inner and the outer portions. 
The latter, consisting of the cork and the parenchyma of the outer 
bark, break uniformly and short, in so far as dead portions of the 
bast are not, through the formation of bork, drawn into the ex- 
ternal coating or periderma. , 2 
In opposition to this uniform, quite smooth, so-called corky 
fracture, the inner layer of stronger barks docs not present an _ 
even fractured surface, but there project therefrom isolated, com- _ 
pact bundles of fibres, which are extended in the direction of the axis. — 
1 Compare Berg, Chinarinden der pharmakognost. Sammlung in Berlin, 1865, p. 39; 
Fliickiger, Fahresbericht der Pharmacte, 1871, p.95; Vogl, Fatsche Chinarinden, 1876, ; 
