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PHARMACEUTICAL BOTANY 
ALEURONE GRAINS 
Aleurone grains are small bodies found in seeds particularly those 
containing oil, and like starch grains often are characteristic of the 
genus or species. Each aleurone grain consists of a ground sub¬ 
stance (composed of amorphous proteid matter soluble in water, 
dilute alkali or acid), in which are usually embedded one or more 
phyto-globulins (insoluble in cold water, but soluble in less than i per 
cent, solution of an alkali, in dilute HC 1 and acetic acid), one or more 
transparent globular globoids composed of Ca and Mg phosphate 
Fig. 39. —To show aleurone grains. A, cells from cotyledon of seed of garden 
bean; n, aleurone grains; m, starch; B, cells from endosperm of castor bean; a, 
a, aleurone grain; l, ground substance; k, phytoglobulin; 1, globoid. (A, After 
Sachs; B, after Frank.) 
(insoluble in water and dilute potash solution but soluble in 1 per 
cent, acetic acid solution), and frequently a crystal of calcium 
oxalate , the whole being enclosed by a protoplasmic membrane (so¬ 
luble in water). (Fig. 39.B.) 
The proteins insoluble in the cell-sap water are made soluble for 
translocation by means of proteolytic enzymes which change them 
into proteoses and peptones. 
20. Mucilages and gums are those substances occurring in plants 
which are soluble in water or swell in it, and which are precipitated 
by alcohol. 
Mucilage is formed in plants in several ways, viz.; either as a 
product of the protoplasm, as a disorganization product of some of 
the carbohydrates, as a secondary thickening or addition to the cell 
wall, or as a metamorphosis of it. In the first two cases the mucilage 
is called cell-content mucilage ; in the last two, membrane mucilage. 
