January 28, 1898.] 



SCIENCE. 



125 



in whose maturity their ridges may have 

 even crests, like those of the Alleghenies. 

 So a statement in an earlier paragraph, 

 ' The Adirondaeks rose as an insular land 

 area in the earliest Paleozoic sea,' may un- 

 fortunately confirm the prevailing error that 

 the Adirondaeks were lifted out of water in 

 the earliest Paleozoic sea, in spite of the 

 preceding clause to the effect that they were 

 first elevated in Archean time. The con- 

 clusion that the Adirondaeks sank as an in- 

 sular land in the Paleozoic sea is pot pre- 

 sented. 



PLATEAXrs, TABLELANDS AND BASINS. 



An article on the Topography of Mexico, 

 by H. M. Wilson, with a hypsometric map 

 (Bull. Amer. Geogr. Soc, XXIX., 1897, 

 249-260) , presents an account of the desert 

 plains of the interior, including the follow- 

 ing statement : " According to common be- 

 lief, Central Mexico consists of a vast 

 plateau. In fact, it is a great basin or de- 

 pression, ribbed with many irregularly dis- 

 posed or disconnected mountain ranges, 

 buttes and isolated ridges, which are sep- 

 arated by broad valleys and plains. Many 

 of these plains are the beds of ancient 

 lakes, like those of Salt lake or Humboldt 

 valley in Utah and Nevada, and have no 

 drainage outlet to the sea " (p. 252). The 

 objection here implied to the use of the 

 term, plateau ' is not valid, if a compara- 

 tively even surface at a considerable eleva- 

 tion is all that is required to make a 

 plateau ; for Mexico has plenty of that sort 

 of surface ; nor is the discontinuity of the 

 plains a sufficient reason for placing them 

 outside of the class of plateaus, inasmuch as 

 many accepted plateaus are discontinuous, 

 either from the addition of volcanic cones, 

 the survival of residual mountains, or the 

 excavation of canyons and valleys. Table- 

 land or table mountain is an inappropri- 

 ate name for an elevated region with 

 still higher borders, although fitting for 



such great clifif-edged plateaus as those 

 trenched by the Colorado canyon, or 

 for such huge plateau remnants as Rora- 

 ima and Kukenam, in G-uiana. Mesa 

 is limited to smaller examples of uplands 

 with precipitous borders on one or all sides. 

 Basin is already used too indefinitely ; be- 

 ing applied to ocean basins, river basins and 

 lake basins, as well as to these arid depres- 

 sions, floored over with accumulating waste 

 from their higher rims. Penck has lately 

 introduced the German word Wannen to re- 

 place the indefinite Beclcen, for depressed 

 areas with centripetal drainage. Bolson is a 

 Spanish-American term quoted by Hill as 

 locally applied to the interment depressions 

 of the Mexican region. The curious thing 

 in all this is that English-speaking geogra- 

 phers have no simple name with which to 

 designate this well characterized class of 

 land forms. 



W. M. Davis. 



CURRENT NOTES ON ANTHROPOLOGY. 

 THE BLACK RACE. 



A SUCCINCT exposition of the ethnography 

 of the black race is given by Professor 

 Hamy in VAnthropologie, Vol. VIII., p. 

 257, sq. 



It embraces one-tenth of the human 

 species (about 150,000,000) ; and of this, 

 one-tenth again (1,500,000) has existed 

 outside of Africa, in Melanesia, etc., from 

 a period when those numerous islands were 

 part of the Asiatic continent. 



In Africa, within five degrees north and 

 south of the equator, is the territory of the 

 dwarfs, probably once stretching nearly 

 across the continent. North of this, on 

 both sides of Lat. 15° north, and from the 

 Nile to the Atlantic, are the groups of pure 

 blacks, of average stature, nearly all agri- 

 cultural, and with a knowledge of iron 

 from a remote date. South of the dwarfs 

 are the Bantu peoples, extending from ocean 

 to ocean, with notable physical differences, 



