JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org.. American Geographical Society is collaborating with JSTOR to digitize, preserve and extend access to Geographical Review. [With separate map, P1. II, facing p. 414) HE extent and hydrography of the land areas in the world served by interior basin drainage are of interest to all students of earth science. The physiographic relations of a third of the lands would be changed if precipitation everywhere found its way to the oceans, as is the normal condition in most inhabited regions. In the physical economy of the globe one may consider as two separate domains the regions of interior and the regions of oceanic drainage.It is convenient to describe each of these two great regions by a single word: we may term through-flowing, or ocean, drainage "exoreism" (ex-o-re-ism, from the Greek P ', out, and petv, to flow), interior basin drainage "endoreism" (en-do-re-ism, from 'v, in, and pstv).' In this paper we shall attempt to define the extent of the endoreic, or interior-basin, domain and explain its causes. The deserts are par excellence the domain of interior-basin drainage, or endoreism. But they present a particular case where run-off is nil and for which the term "areism " is proposed (a-re-ism, from a, privitive, and p-Tv).
EARLY WORK ON THE PROBLEM
Richthofen2 distinguished between the peripheral and the central regions of Asia, the latter marked by an arid climate and interiorbasin drainage. The first and, up to the present, the only attempt to represent cartographically the extent and disposition of interior-basin drainages is inBerghaus' Physikalischer Atlas, Plate No. i6, I89I, which has been reproduced in divers other works. John Murray, in a paper read before the Royal Society of Edinburgh on Jan. I7, I887, gave the first estimate of the inland drainage area.3 He placed it at about a fifth of the land surface, or II,486,350 square miles, a figure only a little less than that of the arid regions (I2,200,000 square miles), or regions of annual rainfall under I0 inches. His calculation was made on an equal-area projection on which were superlaid the 1 Emmanuel de Martonne: Areisme et Indice d'aridite, Comptes Rendus de l'Acad. des Sci. [de Paris], Vol. I82, I926, pp. I395-I398. 2 Ferdinand von Richthofen: China: Ergebnisse eigener Reisen und darauf gegruindeter Studien, (5 vols.
