Page:The New International Encyclopædia 1st ed. v. 12.djvu/493

* LONGEVITY. 435 LONGFELLOW. hardness in its tissues; (4) it must be large and have a considerable extent of surface; and (5) it must rise into the atmosphere. Hildebrand shows that the duration of life in plants is by no means completel}- fixed and that it may be ver' considerably changed tlirough the agency of the external conditions of life, lie points out the fact that in course of time, and under changed conditions of existence, an annual plant may become perennial, or vice versa. That lon- gevity depends on the environment, especially temperature, is also proved by the fact observed in botany that in certain genera of plants there are species which are annuals in the temperate zone, wliile other species in the tropics are tree- like and live many years. Great age in animals is by no means confined to the higher vertebrates. A specimen of sea- anemone (Actinia mesemhry anthem um) lived in an aquarium in Edinburgh fijom 1828 to August 4, 1887. In the Roman fish-ponds lampreys were reputed to have reached their sixtieth year. The crocodile lives a century and continues to grow till it dies; pike and carp are said to have lived 150 years; eagles, falcons, and crows a cen- tury. A white-headed vulture in the Schonbrunn Zoological Gardens is known to have been in captivity for 118 years. The smallest singing birds live ten. years, while the nightingale and blackbird survive twelve to eighteen years. It is supposed that eider ducks may reach the age of nearly a century. Of mammals, only man, the elephant, and the whale live to be a hundred years old. The horse and bear rarely reach an age of 40 years, the lion 35, the wild boar 25, the sheep 15, the hare 10, and the squirrel and mouse (i years. As Weisman states, the mini- mum duration of life necessary for the species is much lower than among birds. Of Crustacea, the crayfish is said to live 20 years; the queen of the honey-bee lives one or two years, but has been kept for five, while Lubbock kept one female ant over tliirteen years and another nearly fifteen years, which continued to lay fertile eggs throughout her life. The initial and most fundamental cause of longevitv in plants is the favorable nature of tho environment, the external conditions of life, par- ticularly temperature. It is most probable that this profoundly aft'ects the duration of life in animals. SeeGKOWTH; ]Metabolism. Another factor is hereditj'. It is well Icnown that longevity runs in families, is hereditary, and that, although individuals who attain a great age may be exposed to the same exigencies of life as those who die young or in middle life, they outlive their generation. The longevity of man is usually given as 100 years, but there are many autlicntic instances of people reaching 108 years. Beyond that limit, however, cases are very rare. The great majority of long-lived individuals liave been of medium height and weight, of quiet, regular habits, moderate eaters and temperate drinkers or abstainers. Tobacco seems to play but small part. Women live longer than men, probably because after the child-bearing period the}' are less exposed to injury and disease than men. See Life, ilEAX Duration of. That the average length of human life has been nearly doubled within a few centuries is due to imjiroved condition^ of living, to the progress of civilization, and especialh' to improved sanitary conditions. Thus the mean duration of human life in France at the clo^c <jf the eighteenth centurv was 2S) years; in the period from 1817 to 183*1 the average ro.se to 39 years, and between 1840 and 185!) to 40 years. For England it has been from 3!) to 43. For Massachusetts the average is about 40, and in New York City 33.3. The mean normal longevity may not be the same in all races. The negroes of Senegal develop earlier than the white man, but they are shorter-lived. Yet when reared in the United States they live to a great age. This is another proof of the profound influence of the mode and general con- ditions of life on longevity. There is also a close correspondence between the duration of life in the individual and that of the species. Most specific forms are compara- tively short-lived. They have originated, flour- ished, and died out within the limits of a geo- logical epoch; while what arc called 'persistent' forms, such as Lingulella, Linudus.Ceratodus, etc., have by reason of their great vitality outlived en- tire fauniE and endured for millions of years, and are now flourishing in apparently undimin- ished vigor. See Extinction or Species. BiBUOGRAPllY. Weismann, Esuni/s upon. He- redity and Kindred Bioloijical Problems (Eng. trans. Oxford, 188'&) ; Lankester, Oil Comparative Longerity in Man and the Loicer Animals (Lon- don, 1870) ; Hildebrand, "Die Lebensdauer, etc., der Pflanzen," in Engkr's lioton. Jahrbuch, vol. ii. (Leipzig, 1881) ; Thomas, Longevity of Man; Hufeland, Art of Prolonging Life; Flourens, De la longeiite hninuine; Quetelet, Physique socials, LONGTELLOW, Henry U'adswortii (1807- 82). The most popular of American poets. He was born in Portland. !Maine, February 27, 1807, and was the second son of Stephen Longfellow, a well-to-do lawyer of Portland, and Zilpah Wadsworth. Through his mother's family Long- fellow was descended from Jolin Alden and Pris- cilla Mullens, whom he made famous in his poem "The Courtship of ililes Standish." He early showed a liking for literature. As early as 1820 he had printed verses in the Portland Gar zette. In 1825 he was graduated in the same class with Hawthorne from Bowdoin College, Brunswick, Maine, after a course marked by studiousness and quiet. He was immediately nuide professor of modern languages at Bowdoin, but was allowed to go to Europe for three years, to fit himself for his profession. In Europe, from 1826 to 1829, his life was passed in hard study in Paris, and in Italy and Spain. He was married in 1831 to Miss Jlary Storer Potter, who died in 1835. Aside from a col- lection of juvenile poems, in 182G, and his trans- lation of a French grammar for use in his classes, in 1830, his first literary work was the translation of the Cophis de Munriquc (1833). The same year he published the first part of Outre-Mer:' A Pilgrimage Beyond the Sea, and the second part the following year (in book form, 1835), both rather stilted sketches of travel. In 1835 he resigned his chair at Bow- doin, and went again to Europe for a year's studv, in preparation for the Smith professor- ship" of modern languages at Harvard, which had been held bv George Ticknor, the historian of Spanish literatu'e. From 1836 his residence was in Cambridge, where he first occupied and afterwards owned the Craigic Hoiise, the head- quarters of Washington during the operations about Boston in the War of Independence.