Arthropoda (är-thrŏp´o-dȧ).—Articulated animals with jointed feet, as crabs, insects, etc.
Asexual (ȧ-sĕks´ū-al).—A term applied to animals, as Aphis, in which the reproductive organs are imperfect, and the young are produced by budding.
Auricle (a̱´rĭ-k´l).—The cavity of the heart which receives the blood and transmits it to the ventricle.
Bacteria (băk-tē´rĭ-ȧ).—Microscopic vegetable organism, belonging to the class Algæ, usually in the form of a jointed, rod-like filament, and found in putrefying organic infusions. Bacteria are destitute of chlorophyll, and are the smallest of microscopic organisms. They are very widely diffused in nature, and multiply with marvelous rapidity. Certain species are active agents in fermentation, while others appear to be the cause of certain infectious diseases.
Batrachia (bȧ-trā´kĭ-ȧ).—Applied to frogs, toads, and salamanders.
Bimana (bĭm´ȧ-nȧ).—Two-handed animals whose posterior extremities are used only to keep them in an erect position, and for the purpose of locomotion. They comprise the varieties of man.
Blastoderm (blăs´tō-derm).—The outer layer of the germ-cells of the embryo.
Carapace (kăr´ȧ-pās).—A sort of shell which protects and encloses the bodies of tortoises and some reptiles, etc.
Carnivora (kär-nĭv´ō-rȧ).—Group of mammals, including the lion, tiger, wolf, bear, seal, etc. They feed upon flesh, though some of them, as the bears, also eat vegetable food. The teeth are large and sharp, suitable for cutting flesh, and the jaws powerful.