. Botany for high schools and colleges. Botany. 0BYSTAL8. 61 (a) In studying plant-crystals it is only necessary in most cases to make thin longitudinal sections, and to mount in the usual way in water. (6) The calcium carbonate crystals may Le distinguished from those of calcium oxalate by treatment with hydrochloric acid, which dissolves both, the former with effervescence, the latter with none. Under treatment with acetic acid the calcium carbonate crystals dissolve (with efEervescence, of course), while those of calcium oxalate do not dissolve. (c) Acicular crystals, or raphides, may be be
. Botany for high schools and colleges. Botany. 0BYSTAL8. 61 (a) In studying plant-crystals it is only necessary in most cases to make thin longitudinal sections, and to mount in the usual way in water. (6) The calcium carbonate crystals may Le distinguished from those of calcium oxalate by treatment with hydrochloric acid, which dissolves both, the former with effervescence, the latter with none. Under treatment with acetic acid the calcium carbonate crystals dissolve (with efEervescence, of course), while those of calcium oxalate do not dissolve. (c) Acicular crystals, or raphides, may be best obtained from the Evening Primrose, EpiloMum, Fuchsia, and other Onajrraceae, also from tlie Balsam (Impatieiis Bid>.amiiia), Garden Rhubarb, and the new growths of the Virginia Creeper, and the grape-vine. Raphides may also be obtained from some of the Monocotyledons with equal ease, , Tradescantia, Indian turnip (Arismma), Calla, Narcissus, Lily-of-the-Valley, etc. ((f) The other crystal forms are obtainable from the bark of the lo- cust (Robinia), elm, Soya, leaves of Begonia, bulb-scales of onion, garlic, and leek, the root-stock of Iris, etc. (c) Cystoliths may be readily studied by making cross-sections of the leaves of Urtica, mulljerry, hop, hemp, fisr, Celtis, and other Urti- cncem. Tliey are said by Sachs to occur only in tliis order and the Aeanthacem.*. Fig. 48.—CyBtolith from the epidermis of the upper surface of the leaf of Urtica fnacrophylla, from a cross section of the leaf. X 235.—After De Bary. (/) Plant-crystals appear to be surrounded by a thin layer of proto- plasm ; probably they are separated out from the cell sap only through the influence of protoplasm. It is further probable that they are resid- ual products of chemical actions in the plant, and, as they appear never to be made use of by the plant, we must regard them as to a certain extent of the nature of excretions. *"Lehrbuch," 4te auf., p. 69. However, cystoliths, or struc
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectbotany, bookyear1888
