horizontal integration See vertical integration
Horkheimer, Max (b. Feb. 14, 1895, Stuttgart, Ger.—d. July 7, 1973, Niimberg) German philosopher and social theorist. He received his Ph.D. in philosophy at the University of Frankfurt in 1922. In 1930 he became director of the university’s newly founded Institute for Social Research. Under his leadership, the institute attracted an extraordinarily talented array of philosophers and social scientists, including Theodor Adorno, Erich Fromm, and Herbert Marcuse; collectively (with Horkheimer) they became known as the Frankfurt school. When the Nazis came to power in 1933, Horkheimer moved the institute to New York City, where he directed it until 1941; he reestablished it in Frankfurt in 1950. In his 1937 essay “Traditional and Critical Theory,” he contrasted what he considered the socially conformist orientation of traditional political philosophy and social science to the brand of critical Marxism favoured by the institute, an approach known as critical theory. His collaboration with Adorno, Dia¬ lectic of Enlightenment (1947), is a pessimistic work that traces the ori¬ gins of fascism and other forms of totalitarianism to the Enlightenment concept of “instrumental” reason.
hormone Organic compound (often a steroid or peptide) that is produced in one part of a multicellular organism and travels to another part to exert its action. Hormones regulate physiological activities including growth, reproduction, and homeostasis in vertebrates; molting and maintenance of the larval state (see larva) in insects; and growth, bud dormancy, and leaf shedding in plants. Most vertebrate hormones originate in specialized tis¬ sues (see endocrine system; gland) and are carried to their targets through the circulation. Among the many mammalian hormones are ACTH, sex hormones, thyroxine, insulin, and epinephrine. Insect hormones include ecdysone, thoracotropic hormone, and juvenile hormone. Plant hormones include ethylene, abscisin, auxins, gibberellins, and cytokinins.
Hormoz or Hormuz \hor-'miizV formerly Ormuz \6r-'miiz\ Island and town, Iran. Situated in the Strait of Hormuz, the island is 5 mi (8 km) off the coast of Iran. Hormoz village is its only permanent settlement. After the Arab conquest, it was an important market that by ad 1200 monopolized trade with India and China. Marco Polo twice visited there. Taken by the Portuguese in 1514, it was retaken by Persia in 1622. The town declined with the growth of the port of Bandar 'Abbas on the main¬ land.
Hormuz, Strait of formerly Strait of Ormuz Channel linking the Persian Gulf with the Gulf of Oman and the Arabian Sea. It is 35-60 mi (55-95 km) wide and separates Iran from the Arabian Peninsula. It con¬ tains the islands of Qeshm, Hormoz, and Hengam and is strategically and economically important as a route for oil tankers collecting from various ports on the Persian Gulf.
Horn, Cape Southern extremity of South America. Located on Horn Island in the southern Tierra del Fuego archipelago, it projects south into Drake Passage. It was named Hoom for the birthplace of Dutch navigator Willem Schouten, who rounded it in 1616. Navigation of the rough waters around the cape is hazardous, and the climate is windy and cold year- round.
Horn of Africa Region of eastern Africa. The easternmost African
extension of land between the Indian occupied by Ethiopia, Eritrea, Soma¬ lia, and Djibouti, whose cultures have been linked throughout their long history.
hornbill Any of about 45 species of Old World tropical birds (family Bucerotidae) noted for the bony hel¬ met on the bill of some species. Hombills range from 16 to 63 in. (40-160 cm) long, and typically have a large head, prominent bill, thin neck, broad wings, long tail, and brown or black plumage, usually with bold white markings. They nest in cavities, usually in large trees. The male of most species walls up the female in the nest, closing the hole with mud, except for a small open¬ ing through which he passes food.
Ocean and the Gulf of Aden, it is
Red-billed hornbill (Tockus erythrorhyn- chus)
MARK BOULTON-THE NATIONAL AUDUBON SOCIETY COLLECTION/PHOTO RESEARCHERS
© 2006 Encyclopaedia Britannica, Inc.
896 I hornblende ► Horowitz
The female breaks out after the eggs hatch, but the young may be walled up again.
hornblende Any of a subgroup of amphibole minerals that are calcium- iron-magnesium-rich and monoclinic in crystal structure. Hornblende, whose generalized chemical formula is (Ca,Na) 2 (Mg,Fe,Al) 5 (Al,Si) 8 0 2 2(OH) 2 , occurs widely in metamorphic and igneous rocks. Common hornblende is dark green to black in colour and usually found in middle-grade metamorphic rocks (formed under medium conditions of temperature and pressure). Such metamorphic rocks with abundant horn¬ blende are called amphibolites.
Hornblower, Jonathan Carter (b. July 5, 1753, Chacewater, Corn¬ wall, Eng.—d. March 1815, Penryn, Cornwall) British inventor. He and his father, Jonathan (1717-80), worked for James Watt. Seeking to improve on Watt’s steam-engine design, he devised the first reciprocating compound steam engine (patented 1781); his engine had two cylinders (see piston and cylinder), a significant contribution to efficiency. In 1799 it was judged an infringement on Watt’s patent.
Hornbostel Vhom-.bos-UL, Erich (Moritz) von (b. Feb. 25, 1877, Vienna, Austria—d. Nov. 28, 1935, Cambridge, Cambridgeshire, Eng.) Austrian ethnomusicologist. Born into a musical family in Vienna, he was by his teens a skilled pianist and composer. After taking a doctorate in chemistry, he became involved in psychological research, and his studies of tonal perception were pioneering research in what would become the field of ethnomusicology. He helped establish the research program for the field and the methods used to carry it out, including field recordings. In 1912 he devised, with Curt Sachs, the cross-cultural system of classifica¬ tion of musical instruments that is still in use.
Horne, Lena (Calhoun) (b. June 30,1917, Brooklyn, N.Y., U.S.) U.S. singer and actress. In her youth she was a dancer at Harlem’s Cotton Club, and by age 18 she was singing with popular bands. She starred in many films, including Stormy Weather (1943) and The Wiz (1978). Her album Lena Horne at the Waldorf-Astoria (1957) was a great success, as was her appearance in the musical Jamaica (1957). Her one-woman show, Lena Horne: The Lady and Her Music (1981), was hailed as her masterpiece. She continued to perform and record into the 1990s.
Horne, Marilyn (b. Jan. 16, 1934, Bradford, Pa., U.S.) U.S. mezzo- soprano. Horne studied voice at the University of Southern California and with the soprano Lotte Lehmann (1888-1976). In 1954 Horne dubbed the singing voice of Dorothy Dandridge in the film Carmen Jones , and that same year, she made her opera debut with the Los Angeles Guild Opera. Her long and influential association with the bel canto (a singing style based on an exact control of the intensity of vocal tone) repertoire began in 1962, and she played an important role in the revival of operas by George Frideric Handel and Gioacchino Rossini. Her distinctive voice was even throughout its remarkably wide range, and she had virtuoso control of breath and pitch. She retired in 2000 after a long career.
Africa, India, Myanmar (Burma), and the Indonesian archipelago. They typically prey on rodents.
horned toad or horned lizard Any of about 14 species of lizards of the genus Phrynosoma, family Iguanidae. They usually have dagger¬ like head spines (horns) and a flattened oval body with pointed fringe scales along the sides. Species range from about 3 to 5 in. (8 to 13 cm) long. They are found from British Columbia, Can., south to Guatemala and from the U.S. states of Arkansas and Kansas westward, usually in desert or semidesert sandy country. They eat mainly ants. They hide by changing their colour pattern and wriggling sideways into the sand until all but the head is covered. They may defend themselves by inflating the body quickly and (rarely) spurting blood from the eyes.