Calcareous.—Containing earthy carbonates, particularly calcium carbonate (chalk).
Cambium.—Narrow living cells, which are constantly dividing and giving rise to new tissues (see [fig. 33], [p. 57]).
Carbonates, as used in this book, refer to the combinations of some earthy mineral, such as calcium or magnesium, combined with carbonic acid gas and oxygen, formula CaCO3, MgCO3, &c.
Carpel.—The closed structure covering the seeds which grow attached to it. The “husk” of a peapod is a carpel.
Cell.—The unit of a plant body. Fundamentally a mass of living protoplasm with its nucleus, surrounded in most cases by a wall. Mature cells show many varieties of shape and organization. See Chapter VI, [p. 54].
Centrifugal.—Wood or other tissues developed away from the centre of the stem. See [fig. 65], [p. 97].
Centripetal.—Wood or other tissues developed towards the centre of the stem. See [fig. 65], [p. 97].
Chloroplast.—The microscopic coloured masses, usually round, green bodies, in the cells of plants which are actively assimilating.
Coal Balls.—Masses of carbonate of calcium, magnesium, &c., generally of roundish form, which are found embedded in the coal, and contain petrified plant tissues. See [p. 28].
Concretions.—Roundish mineral masses, formed in concentric layers, like the coats of an onion. See [p. 27].