ON THE ANATOMY OF DRUGS. 
459 
for dilating the various secretory passages, and the material appears likely to 
supersede those hitherto in use. 
Acrorjens. —Passing from the lowest types of vegetation to those next higher 
in the scale, a great advance in organization is to observed. In Acrogens not 
only do we find a distinct fibro-vascular system, but it becomes an important 
element in their structure, forming the framework or skeleton of the plant. 
Still the plants are all of humble, herbaceous growth, except the few tropical 
tree-ferns, and none of them possess either true wood or a true bark. 
From the lower members of the group but one pharmaceutical substance is 
derived, that known as Lycopodium^ which consists of the spores of the common 
Club-moss {L. clavatuni). These spores make a pretty microscopical object, but 
there is nothing we need dwell upon in connection with them. They may be 
mounted either dry or in diluted glycerine, for examination by reflected or 
transmitted light. 
The various genera of Ferns {Filices) constitute the higher portion of the group. 
Their general anatomy may be readily understood from the section of a good-sized 
stem of any species, as all are referrible to one common type of structure. Who 
has not in boyhood cut the stem of the common Bracken (Pteris aqidlina) near 
its base, to see the little pictured Oak-tree so plainly marked out by the pecu¬ 
liar disposition of the fibrous bundles ? The stem, and the rhizome of course 
follows the same rule, is built up of cellular tissue, loose in the centre, and more 
closely packed towards the circumference, and this is traversed by fibro-vascular 
bundles of peculiar character, arrayed in an irregular circle. The bundles con¬ 
sist of two portions, an outer, hard, dark-coloured border, composed of woody 
fibre, and enclosed by it, a lighter mass made up of long, angular, reticulated 
cells, combined so as to form scalariform vessels. The term ‘ scalariform ’ is em¬ 
ployed, on account of the regular transverse lines of deposit giving a ladder¬ 
like appearance. In the rhizomes of some species, especially in that of the Male 
Fern (Nephrodium Filix-mas)^ in addition to the structure above described, there 
are to be found certain intercellular spaces, amd, from the surface of the cells 
forming their boundary, minute, dark-coloured, globular oil-glands projecting 
by a short stalk into the cavity. It is to the oily contents of these cells that the 
rhizomes owe their anthelmintic properties. 
Monocotyledons. —The paramount importance to mankind of Endogenous 
or Monocotyledonous plants depends upon their economic rather than their medi¬ 
cinal products,—chiefly upon the fact that nearly the whole of the farinaceous 
substances used for food are derived from them. But, in addition to those 
yielding an edible farina, there are a multitude of species in common medical 
use. Amongst them the most familiar are— Crocus saiivus, yielding Saffron ; 
Elettaria Cardamomum^ Cardamom-seed; ColcMcum autumnale^ corm and seed ; 
Urginea Scilla, Squill-bulb ; Smilax officinalis^ Sarsaparilla-root; the rhizomes of 
Iris florcntina^ “ Orris-root Acorus Calamus^ Sweet Flag; Zingiber officmale^ 
Ginger; Curcuma longa^ Turmeric ; Veratrum alburn^ White Hellebore; and 
lastly, the fruit of Asagrsea officinalis, Cevadilla. If we may be allowed to in¬ 
clude the fruit of another plant, interesting for its structural peculiarities rather 
than for any medicinal value, we may add that of Vanilla planifolia. 
It would be quite beyond the compass of the present paper to attempt a de¬ 
scription of the histological characters of all or even of any large number of 
these; but a brief account of one or two of them may assist those not familiar 
with the subject to form a correct appreciation of the appearances they present 
under the microscope. It must be borne in mind that Endogens have no true 
bark, and, indeed, no true wood; the harder tissues of even arborescent species, 
like Falm-trees, being composed of distinct fibro-yascular bundles interlacing 
3 II 2 
