e * o *•' *" 
VOL. III.—No. I. —JULY <5, 1872. 
THE MICROSCOPE IN PHARMACY. 
BY HEX BY POCKLIXGTOX. 
{Continued fromXol. II. p. 1025.) 
Pyrethri Radix. —Sections of tills root can onl} r 
be examined to advantage in fluid, and should be put 
up in glycerine or glycerine jelly for preservation. 
Owing to the thinness of the cell walls and the loose 
texture of the root generally, it suffers much distortion 
(structurally) in drying; so that it is almost impossible 
to make a proper examination of the dried root. 
The medulla is present, and somewhat largely de¬ 
veloped, and is irregularly septate, the cavities 
between the septa being somewhat large. The cells 
of the medulla are very thin-walled modified glo¬ 
bose cells, adhering somewhat intimately to each 
other, and varying much in cross-sectional outline. 
Many of these cells display p^i/do-reticulations, 
due to unequal shrinking during exsiccation, which 
may easily mislead a beginner. 
The medullary rays are very large, exceeding 
sometimes by three tunes the breadth of the wood 
wedge ; they are complete and incomplete in nearly 
equal proportion. Their cells resemble those of 
the medulla, becoming more cubical as they ap¬ 
proach the cortex. 
The wood wedges are hardly worth their name, as 
they are merely composed of cubical parenchyma 
cells and vascular (pitted) vessels. These vessels 
are almost scalariform, but do not otherwise possess 
any features of interest, and are out of all propor¬ 
tion, as to size and number, to the £>S£»c?o-wopd 
cells. The only cells in which secondary deposits 
are traceable are the liber cells of the cortical layers, 
which are not otherwise interesting, except in being 
very numerous. The cortical layers consist of cubi¬ 
cal parenchyma; colouring matter receptacula, 
which are cubical cells also; liber cells; and the 
compressed cells of the external layer. Starch is 
present in very small proportion. The granules are 
roundish, and of small medium size. 
Pare hue Radix. —As is tolerably well known, the 
so-called root of Pareira of British pharmacy is really 
the stem, generally of Cissampelos Pareira, but often 
of some other species. The structure of the B. P. so- 
called root is exceedingly interesting and charac¬ 
teristic. I describe the true Pareira Brava from a 
portion of a stem about half an inch in diameter. 
Medulla .—The medulla is very visible to the naked 
eye, is often very eccentric, and throws out radiating 
processes (medullary rays) to the bark. These are also 
visible without a lens. The cells of the medulla 
are of medium size, are somewhat irregular, and 
Third Series, No. 100. 
variable in size and shape ; some contain a daimsfr 
yellow colouring matter, nearly all contain staich 
The starch granules are very variable, both m si/ 
and shape. The large ones may be best described 
as flatly compressed lenticular granules, v. 
strongly marked longitudinal hilum. By pmanz^u. 
light these granules give a decided single blacx cio&s. 
The smaller granules are much too variable to be 
grouped under any one characteristic, unless it w eie 
rounded-off polyhedrons. Acicular raphides, or more 
correctly perhaps, as they have not pointed ends, 
T l 1 • J * _1,* J «« /-V AAllto 1 TY O fl II) RT)0— 
elongated 
J Ex Help/ O 5 # , 
prismatic raphides, are contained m spe¬ 
cialized cells near the exterior of the medulla, ana 
very occasionally, but they are then much smahei, 
in the cells of the medulla itself. The true menu a 
cells are distinctly pitted with oval pits, the cell wans 
are slightly coloured yellowish brown, and are evi¬ 
dently considerably thickened by secondary deposits. 
They are generally egg-shaped, often globose; to warns 
the circumference they become more angular, anu 
when the medullary rays strike off, become mm i 
longer in proportion to tiieir other dimensions. 
Medullary Rays .—These are, as has before been 
stated, very well marked. Their cells are somewhat 
loosely attached to each other, and are somewlia 
less angular than usual. Raphide-recepiacuia 
abound in the rays. . 
Vascular Bundles .—Owing to the great size ot 
the medullary rays, the wood masses are well isouneu 
on two sides) They are composed of porous wood 
fibres and pitted vessels ; these latter being °f the 
large size common to all climbing plants. mis 
wood fibres are themselves of the nature of vessels, 
from the largeness of their central cavity and the 
small extent to which their walls have been thick¬ 
ened. They are fragile, adhere closely to each 
other, and are of considerable length, slightly tapei - 
ing towards each end; oval in cross section, and closely 
pitted. The pits are usually in the centre of a re¬ 
latively large ring, and are oval; they do not con¬ 
tain either starch or raphides. The vessels ^ an 
much in size, and are exceedingly interesting. 1 .e 
argest are reticulated in an intricate mamiei , 
he pits oval, and in a central bordering fox- 
ow the pattern of the reticulation somewhat 
dosely, the axis of the pore lying often parallel 
vith the course of a supposed spiral wound witli- 
n the cell. The ends of these ducts are, as Quekeit 
■emarked long since, somewhat flattened; aie often 
dosed with a double septum, or more corrcctlv with 
iepta, being the unabsorbed membrane of the re.>pec- 
ive cells. The reticulations on these septa are 
)ften verv remarkable, and resemble veiy cm mb 
