30 
PLANT MORPHOLOGY. 
linum, lobelia, marrubium, mentha piperita, mentha viridis> 
mezereum, myristica, nux vomica, pareira, pliysostigma, piper, 
podophyllum, rhus glabra, rosa gallica, sabina, sanguinaria, 
santonica, sassafras, senega, serpentaria, sinapis alba, sinapis nigra, 
spigelia, staphisagria, strophanthus, sumbul,valerianaand zingiber. 
Calcium oxalate crystals have been mistaken for 
crystalline sugar, and it should also be pointed out 
that some of the soluble carbohydrates, as hesperidin 
and inulin, may be mistaken for sphere-crystals of 
calcium oxalate, which are of rare occurrence. Some of 
the soluble carbohydrates, including inulin, occur in 
either sphere-crystals or irregular spherical aggregates, 
which are more or less easily soluble in water. They 
are found in buchu, hedeoma, inula, lappa, pyre- 
thrum, taraxacum and triticum. 
(c) COMPOSITE BODIES. 
1. ALEURONE GRAINS. 
Aleurone or protein grains consist of protein- 
crystalloids, globoids and a ground mass, the whole 
being inclosed by a membrane-like material. Calcium 
oxalate crystals may, or may not, be present; when they 
do occur, they are of special value in the study of the 
plants in which they are found, as in the fruits of the 
Umbelliferse. 
The aleurone grains arise in the cell sap, usually in 
that of seeds ; the calcium oxalate, if present, separates 
first; then the globoids, which are small globular bodies 
composed of the double phosphate of calcium and 
magnesium, appear, after which the crystalloids arise, 
and finally, from the mother liquor, the ground mass 
separates, the whole becoming inclosed in a sac-like 
membrane. 
Aleurone grains may be studied by taking advan- 
tage of the difference in solubility of the substances 
