388 CINCHONA BARKS. 
section the fibres appear in distinct and very neatly arranged 
layers, which are traversed by fine canal-like pores;* in outline 
they are spherical or angular, frequently somewhat extended in a ra- 
dial direction, and the cavity mostly confined to a dark fissure or a 
point. Since the bast-fibres terminate at the ends in a point, which, 
however, is not actually sharp, the dimensions of a transverse section 
at different heights is subject to variation. The larger diameter of 
the strongest fibres attains to about 200 micromillimeters, but is 
usually only one-half or one-third of this size. 
On a longitudinal section the bast-fibres of the Cinchonas are 
seen to be proportionately shorter than the corresponding cells of 
many other barks, although their length is within the limits of ordi- 
nary measurements, and easily amounts to from 2 to 3 millimeters, 
They present themselves, in so far as they do not stand completely 
isolated, with their pointed ends wedged above and between each 
other, and never transversely connected, but rather always either 
simply curved, or at the most, sabre-shaped; they are, however, 
mostly spindle-shaped. In consequence also of their shining yellow 
or yellowish-red color they may readily be observed in the other 
tissue. 
The transverse sections of strong bast-fibres are very hand- 
some objects in polarized light, in that they display a black cross, 
and besides, with only slightly thicker sections, vivid colors in the 
quadrants, 
The finer spiral rudiments of their structure can only be observed _ 
when the bast-fibres have first been boiled in hydrochloric acid, and 
subsequently placed in an ammoniacal solution of oxide of copper.” 
The bast-fibres of the true Cinchonas are characterized by their 
considerable thickness and lignification, as also by their simple form 
and pointed ends. Although in the beginning making their appear- 
ance in an isolated form in the youngest axes, they afterward 
arrange themselves in various ways, so that the individual species 
of Cinchona are also to a certain extent characterized by their 
peculiarities in this respect. 
The bast of the Cinchona barks, 7. ¢., that of the true Cinchonas, 
does not appear distinctly reticulated. Even where lignified bast- 
fibres occur in large numbers, they do not form groups of large 
dimensions, nor branched, long and compact bundles;? and espe- 
_ 1 De Bary, Vergleichende Anatomie der Vegetationsorgane, 1877, Pp. 139. 
_ _ # Compare Hofmeister, Verhandlungen der sitchs. Gesellschaft der Wissenschaften 
: no - (1858), p. 32; Fliickiger, Grundlagen der pharm. aarenkunde, ore, p. oh 
_ * Compare De Bary, Anatomie, p. 544. 
