Genus.—A small group within a family which includes all the plants very like each other, to which are all given the same “surname”; e.g. Pinus montana, Pinus sylvestris, Pinus Pinaster, &c. &c., are all members of the genus Pinus, and would be called “pine trees” in general (see “Species”).
Hyphæ.—The delicate elongated cells of Fungi.
Molecule.—The group of chemical elements, in a definite proportion, which is the basis of any compound substance; e.g. two atoms of hydrogen and one atom of oxygen form a molecule of water, H2O. A lime carbonate molecule (see definition of “Carbonate”) is represented as CaCO3.
Monostelic.—A type of stem that contains only one stele.
Morphology.—The study of the features of plants, their shapes and relations, and the theories regarding the origin of the organs.
Nucellus.—The tissue in a Gymnosperm seed in which the large “spore” develops. See figs. [55] and [56], [p. 76].
Nucleus.—The more compact mass of protoplasm in the centre of each living cell, which controls its growth and division. See [fig. 17], n.
Palæobotany.—The study of fossil plants.
Palæontology.—The study of fossil organisms, both plants and animals.
Petiole.—The stalk of a leaf, which attaches it to the stem.