Columbia Encyclopedia

(Encyclopedia) stun gun, hand-held electronic device that produces a high-voltage pulse that can immobilize a person for several minutes with no permanent damage in most cases. It is powered by ordinary batteries, w...

(Encyclopedia) psoriasis sôrīˈəsĭs [key], occasionally acute but usually chronic and recurrent inflammation of the skin. The exact cause is unknown, but the disease appears to be an inherited, possibly autoimmu...

(Encyclopedia) thresher shark, long-tailed, warm-water shark, genus Alopias. The upper fork of its tail is slender and sickle-shaped and is about equal in length to the rest of the body. This shark uses its tail str...

(Encyclopedia) treehopper, any member of three families of winged insects, remarkable for the curious shapes of most species. The shapes are due to the enlargement of the dorsal (upper) covering of the first thoraci...

(Encyclopedia) bean weevil, common name for a well-known cosmopolitan species of beetle (Acanthoscelides obtectus) that attacks beans and is thought to be native to the United States. It belongs to the family Bruchi...

(Encyclopedia) aardwolf ärdˈwo͝olf [key], carnivore of the hyena family. The aardwolf, Proteles cristatus, resembles the true hyena but is smaller and more delicate. It has less powerful teeth and jaws and five i...

(Encyclopedia) gerbil jûrˈbĭl [key], small desert rodent found throughout the hot arid regions of Africa and Asia. Also known as sand rats, gerbils have large eyes and powerful, elongated hind limbs upon which th...

(Encyclopedia) anaphylaxis ănˌəfəlăkˈsĭs [key], hypersensitive state that may develop after introduction of a foreign protein or other antigen into the body tissues. When an anaphylactic state exists, a secon...

(Encyclopedia) Eustachian tube yo͞ostāˈshən [key] [for Bartolomeo Eustachi], a hollow structure of bone and cartilage extending from the middle ear to the rear of the throat, or pharynx, technically known as the...

(Encyclopedia) game laws, restrictions on the hunting or capture of wild game, whether bird, beast, or fish. After the Norman Conquest (1066), England enacted stringent game laws, known as the Forest Laws, which mad...