Decembek 4, 1896.] 



SCIENCE. 



829 



deep oceanic circulation. (See Science III., 

 185, 824.) 



THE EAST AND WEST INDIES. 



Prop. K. Martin, of Leyden, discusses 

 the origin of the above-named region (Zur 

 Frage nach der Enstehung des ost- und 

 westindischen Archipels. Hettner's Geogr. 

 Zeitschr., II., 1896, 361-378). His style of 

 treatment is elementary and somewhat in- 

 complete, and his method does not reach 

 far into the past. Sea cliffs cut in elevated 

 coral reefs are described at three levels on 

 Curagao, where the successive steps seem 

 to be of artificial regularity. As the cliffed 

 reef rings around the island with small in- 

 terruption, it is regarded as an uplifted 

 atoll. Other examples are given. In the 

 East Indies, on Saparua, east of Amboina, 

 eleven terraces are found in elevated reefs ; 

 on Buton, southeast of Celebes, nine. The 

 coastal plain of Dutch and British Guiana 

 slopes gently northward ; here reefs are 

 wanting, as the shallow impure water was 

 unfit for coral growth; but former shore 

 lines are distinctly marked by elevated 

 beaches, largely composed of shells, like the 

 existing beach walls. Fourteen of these 

 have been counted, Paramaribo being on 

 one of them. Elevated coral reefs are 

 again wanting on the larger East Indian 

 islands, but their marginal plains contain 

 plentiful marine shells of recent species; 

 these being well preserved about Batavia. 

 Additional facts are mentioned, but they 

 hardly cover the wide areas considered. 

 It is concluded that at a recent date the 

 configuration of the shore lines was very 

 unlike that of to-day, and that an exten- 

 sive elevation has been in progress. 



THE RIVER ETSCH. 



Pence gives an account of Etsch, flowing 

 southward through the Tyrol to the Italian 

 plain, where it is known as the Adige 

 (Zeitschr, Deutsch. u. Oesterr. Alpen- 

 vereins, XXVI., 1895, 1-15). The river lies 



somewhat to the east of the axis of a Ter- 

 tiary trough that is included between the 

 Adamello Mountain group on the west and 

 the dissected Dolomite plateau on the east. 

 Below its torrential headwaters, rock is 

 not exposed in the aggraded valley floor. 

 Lateral streams bring in much detritus, 

 forming fans at their mouths and driving 

 the main stream against the opposite valley 

 wall. Up stream from each fan the slope is 

 moderate, and the flood plain is sometimes 

 swampy ; but immediately down stream 

 from the fans the descent is rapid. ISTo 

 cause is assigned for the clogging of the 

 rock-cut valley. The narrow gorge through 

 which the river emerges upon the plain is 

 here, as commonly elsewhere, a result of 

 morainic displacement from the preglacial 

 valley. The valley is slightly incised be- 

 neath the general level of the plain for 

 about a third of the way to the mouth ; but 

 on reaching the level where the ground 

 water of the plain emerges in numerous 

 springs (fontanili) the river becomes an ag- 

 grading stream and rises above its surround- 

 ings, so as to need diking. In this lower 

 part of its course it is turned aside from 

 the Po, whose aggrading action is more 

 powerful, and for this reason the Adige pur- 

 sues an independent course to the Adriatic. 

 Harvard University. W. M. Davis. 



CURRENT NOTES ON 3IETE0R0L0GY. 



CLIMATIC CONTROL OF CIVILIZATION IN 



AFRICA. 



The influence of climate on civilization 

 in Africa was brought out by Scott Elliot 

 before the Geographical Section of the 

 British Association at Liverpool. Africa 

 may be divided into four regions : (1) the 

 wet" jungle, characterized by great heat and 

 continuous humidity; (2) the deserts, with 

 no proper rainy season ; (3) the acacia and 

 dry grass region, with distinct dry and wet 

 seasons, and (4) the temperate grass and 

 forest region, with moderate rainfall, mod- 



