(Encyclopedia) mangemangemānj [key], contagious skin disease of domestic and wild animals. The several types of mange, including follicular and sarcoptic mange, are caused by various minute parasitic…
(Encyclopedia) foot-and-mouth disease or hoof-and-mouth disease, highly contagious disease almost exclusive to cattle, sheep, swine, goats, and other cloven-hoofed animals. It is caused by a virus,…
(Encyclopedia) leptospirosisleptospirosislĕpˌtəspīrōˈsĭs [key], febrile disease caused by bacteria of the genus Leptospirae. The disease may affect dogs, cattle, pigs, sheep, goats, and horses and is…
(Encyclopedia) sociobiology, controversial field that studies how natural selection, previously used only to explain the evolution of physical characteristics, shapes behavior in animals and humans.…
(Encyclopedia) ectoderm, layer of cells that covers the surface of an animal embryo after the process of gastrulation has occurred. This outer layer, together with the endoderm, or inner layer, is…
(Encyclopedia) dentition, kind, number, and arrangement of the teeth of humans and other animals. During the course of evolution, teeth were derived from bony body scales similar to the placoid…
(Encyclopedia) zoology, branch of biology concerned with the study of animal life. From earliest times animals have been vitally important to man; cave art demonstrates the practical and mystical…
(Encyclopedia) poisonous plant, any plant possessing a property injurious to man or animal. Plants may be poisonous to the touch (e.g., poison ivy, poison sumac), or orally toxic (e.g., poison…
(Encyclopedia) polecat, carnivorous mammal of the weasel family. The name refers especially to the common Old World polecat, Mustela putorius, found in wooded areas of N Eurasia and N Africa. Similar…
(Encyclopedia) instinct, term used generally to indicate an innate tendency to action, or pattern of behavior, elicited by specific stimuli and fulfilling vital needs of an organism. Examples of…
