UNORGANIZED CELL-CONTENTS. 
29 
entirely fill the parenchyma cells in which they occur, 
giving the cells a grayish-black appearance and readily 
distinguishing them from other plant cells. Vesque 
supposed that they were tetrahedrons and termed them 
“ Sable Tetraedrique.” They are probably bemihedral 
forms of monoclinic crystals, inasmuch as monoclinic 
prisms occur in neighboring cells in the same plant or 
drug, as in stramonium, quassia, etc. 
Cryptocrystalline crystals are found in the following 
drugs : 
Belladonna? folia, belladonnse radix, cinchona, phytolaccae radix 
and quassia. 
MEMBRANE CRYSTALS. 
There are several forms of crystals which may be 
included in this group. The so-called Rosanoff crys- 
tals consist of rosette aggregates attached to inward- 
protruding walls of the plant cell. These, however, 
do not concern us so much as the large monoclinic 
crystals which have a membrane (called by Payen 
“ tissu special ”) surrounding them. The crystal first 
appears in the cell sap and then numerous oil globules 
appear in the protoplasm around it; later some of the 
walls of the cell thicken and grow around the crystal, 
which they finally completely envelop. 
Crystals of this character and of the sizes given are 
found in the following drugs : 
Aurantii amari cortex, 15-20 ft, and aurantii dulcis cortex, 20-30 ft. 
VEGETABLE DRUGS WITHOUT CALCIUM OXALATE. 
In the following drugs, calcium oxalate crystals are 
either wanting entirely or so few as to be without any 
diagnostic value : 
Aconitum, apocynum, arnicas flores, capsicum, chirata, cimici- 
fuga, colchici cormis, colchici semen, colocynthis, cubeba, digitalis, 
eupatorium, gentiana, grindelia, hydrastis lappa, leptandra, 
