True, Alfred Charles, 1853-1929, American agricultural expert and educator, b. Middletown, Conn., grad. Wesleyan Univ. (B.A., 1873). Associated with the U.S. Dept. of Agriculture from 1889, he was director of its Office of Experiment Stations (1893-1915) and of its States Relations Service (1915-23). He was noted for his work in agricultural education and became dean of the graduate school of agriculture of Ohio State Univ. in 1923.

Either of two folds of mucous membrane that extend across the interior cavity of the larynx and are primarily responsible for voice production. Sound is produced by the vibration of the folds in response to the passage between them of air exhaled from the lungs. The pitch of sound varies with the degree of vocal-cord tension. Sounds are then modified by the tongue, palate, and lips to produce speech. When at rest, the vocal cords lie apart, forming a V-shaped opening (glottis) through which air is breathed. The folds located just above the vocal cords are termed the vestibular or false vocal cords because they are not involved in voice production. Inflammation (as from excessive use) limits the normal contraction of the vocal cords, resulting in hoarseness.

Learn more about vocal cord with a free trial on Britannica.com.

Herbaceous perennial plant (Zingiber officinale; family Zingiberaceae), probably native to South Asia, or its aromatic, pungent rhizome, which is used as a spice, flavouring, food, and medicine. The spice has a slightly biting taste and is used, usually dried and ground, to flavour breads, sauces, curry dishes, confections, pickles, and ginger ale. The fresh rhizome is used in cooking. The leafy stems of the plant bear flowers in dense conelike spikes. Oil distilled from the rhizome is used in foods and perfumes.

Learn more about ginger with a free trial on Britannica.com.

Any member of the more than 85,000 species in the insect order Diptera (the two-winged, or “true,” flies), characterized by the use of only one pair of wings for flight and the reduction of the second pair of wings to knobs used for balance. Dipterans live in all habitats worldwide, including the subarctic and high mountains. They range in size from about 0.05 in. (1 mm) long (midges) to 3 in. (8 cm) long (robber flies). Dipteran larvae break down and redistribute organic materials, and both adults and larvae are a significant link in numerous food chains. Many species are annoying bloodsuckers, and several (e.g., housefly, mosquito, sand fly, tsetse fly) are vectors of disease. Other species cause great damage to agricultural crops. Seealso blowfly, crane fly, fruit fly, gnat, horsefly, leaf miner.

Learn more about dipteran with a free trial on Britannica.com.