and Jloniniior. Dir LiUernliir iiher die Polar- Regionen der Erde (Vienna. 1878). In thia work may be found the titles, classified, of most of the important books that had been written up to the time of its publication. General Greely's Handbook of Arctic Discov- eries (Boston, 1806) also gives valuable lists of books, classi(ied according to the various spheres of Arctic exploration. A fairly com- prehensive work covering The Xatural History, Oeologt/, and Physics of Greenland and Adjacent Regions (London, 1875), was prepared by T. Jones as a manual for the British Admiralty Expedition of 1875-76. The information pre- sented by the contributors to this work extends somewhat beyond the regions "adjacent" to Greenland, but needs to be supplemented, and in a few passages corrected, by the reports of later explorations. Of such reports, the most important are ( 1 ) those of the International Polar Expeditions of 1881-83, published by the various cooperating governments. Those of the United States appeared (a) by Greely under the title, Report on the Proceedings of the United Imitates Expedition to Lady Franklin Bay (Washington, 1888) : (b) l>y Ray, under the title, Report of the Expedition to Point Barron:; that of Austria, by Wohlgemuth, appeared under the title, Osterreichische Polarstation Jan Mayen (Vienna, 1886) : that of Denmark, by Paulsen, under the title, Expedition Danoise, Godthaab (Copenhagen, 1889-93) : that of Great Britain, by Dawson, under the title. Fort Rae (London. 1886); that of Russia, by Andreyeff and Lentz, under the title, Beobachtungen der russischen Polarstationen atif A'oicn/n Senila (Saint Peterlburg, 1886-95), etc. (2) Wright, Greenland Ice Fields and Life in the North Atlantic (New York, 1896), which contains a brief description of the flora and fauna of Greenland and a discussion of Arctic glacial phenomena; (3) Conway, The First Crossing of i<l>it~bergen (London, 1897); (4) .Jackson, .1 Thousand Days in the Arctic (New York, 1899), which deals with Franz-.Josef Land, and The Great Frozen Land (New Y'ork, 1895), which deals with the Samoyed peninsula; (5) Peary, Norlhn-ard Over the Great Ice (New York, 1898). which contains a valuable chapter on the most northern Eskimos; (6) Nansen, Farthest 'North, which sets forth the drift of a vessel frozen in the ice across the Arctic Ocean, Books on Arctic currents are: Dittmar, Das yord-Pohirnierr (Hanover, 1901), and the re- port pul)lished by the Norwegian (Government of the investigations of the ship Ingolf in the region of east Greenland and Iceland. Valuable works on the inhabitants are: Boas, "The Eskimo of Baffin Land and Hudson Bay" {Bulletin, American Museum of yatural His- tory, Vol. XV.); Pecher, The Races of Man and Their tlem/rapliical Distribution (London, 1876); Ratzel.' The History of Mankind (3 vols., translate.l; New Y'ork. 1896). For the distribution of animals consult Heilprin, The (leographirnl and Geological Distribution of Animals (New York, 1887); for the distribu- tion of plants consult Heer, Flora Fossila Arc- iica (7 vols., Zurich, 1868-80). For iin account of exploration in the Arctic regions, see PoL.
Re.searcti. For further information concerning the magnetic phenomena, see ^I.VGXETISM, TeRRESTRI.L.
ARCTIUM, ark'shi-um. See Birdock.
ARCTOID'EA. See Cabnivora.
ARCTOSTAPH'YLOS (Gk. a,«rof, ark-tos, bear -f crrd^i//,, ataphylf, grape-bunch). A genus of shrubs and small trees closely related to Arbutus. Jlost of the .species are American; two, however, are circumpolar. The red bearberry {Arctostaphylos uva-ursi) is one of them. It is a trailing evergreen shrub, which bears small flowers and red berries that are eaten by birds, especially grouse and ptarmigan. Its associated species, Arctostaphylos alpina, has berries which are black when ripe and leaves which are not evergreen. The leaves of Arctostaphylos uva- ursi are used in medicine. They contain tannin, gallic acid, arbutin, erieolin, and ursone, and possess tonic, diuretic, astringent, and nephri- tic properties. The manzanita of California is Arctostaphylos pungens or Arctostaphylos man- zanita. It is a shrub or small tree 30 feet high tnat sometimes forms almost impassable thickets. A number of other species are believed worthy of cultivation in regions adapted to them. Only the trailing forms are entirely hardy. Fossil speci- mens of Arctostaphylos ura-ursi have been found in the clays of the glacial period in northern Europe.
ARCTU'RUS (Gk. apKTo^, arktos, bear, the Great Bear + oi'pof, ouros, guardian). The prin- cipal star in the constellation Bootes (the "herdsman"). Arcturus is of the first magni- tude, and is very conspicuous in the northern heavens.
AR'CUA'TION. See Layering, Arcuation. ARCUEIL, ur'ke'y' (anciently, Lat. Arcus lulianus). A suburb of Paris lying four miles south of that city (Map: Paris and vicinity). It is a place of resort for Parisian holiday crowds, and is noted for the ruins of an aqueduct built by order of the Roman Emperor Julian, and for several aqueducts of modern times.
AR'CTIS SENI'LIS (Lat., bow of old age). A not very well-chosen term for a change occur- ring in the cornea of the eye, in consequence of fatty degeneration of its marginal part. The term is objectionable, because the change usually commences before the advent of old age; and fur- ther, because the arcus, or arch, is usually con- verted into a complete circle by the time that the patient has reached the age of 60 or 70 years. The arcus senilis usually commences at or even before the age of 40 years, as an opaque whitish crescent, skirting either the upper or lower margin of the cornea; and from this l)e- ginning it extends along the edge, till it finally becomes a complete circle, which some- times assumes a chalky whiteness, and gives to the eye a very peculiar appearance. On careful examination, it may be seen that a narrow inter- val of partially clear cornea always intervenes between the arcus and the opaque sclerotic. As far as the eye is concerned, the formation of this circle is of little importance. It is usually asso- ciated with arteriosclerosis of the blood vessels and fatty degeneration of other portions of the body, including the heart.
ARCY, ar'se', Grotto of. A cavern of remarkable beauty twelve miles east of Auxerre, France. It is supposed to have been used in early times as a stone quarry, and possibly the
