Apkil 1-2, 1895.] 



SCIENCE. 



409 



and Cyrena beds, a great ice-sheet stretched 

 south as far as the valley of the Humber, 

 thus proving the existence of a later ice in- 

 cursion. In the first edition the term kamcs 

 was not difi'erentiated fi-om e^ker and asar, 

 and all of tliem wore believed to have been of 

 marine origin; now he separates the kames 

 from the esker and asar and adopts Hum- 

 mel's river theory of the origin of the latter, 

 besides disowning the necessity of any 

 marine agencj' in the formation of the 

 kames. The accounts of the glacial phe- 

 nomena in Europe and America are given 

 with greater fulhiess in the second edition. 

 The second edition attained a bulk of xxx + 

 624 pages and a larger size of page than the 

 first, which had xxv + 524 pages. 



The third and present edition shows a 

 similar increase in size above its predeces- 

 sor, but not so great a modification in the 

 fundamental principles. About one-fourth 

 of the subject-matter, or that relating chieflj* 

 to Alpine, Arctic and Scottish parts has been 

 revised ; but the other three-fourths have 

 been entirelj' rewritten. The glacial and 

 interglacial deposits of the continent are 

 treated with a fullness that was impossible 

 before. Many sections of it have been 

 visited personally and the results of others 

 verified. Aid has been received from a 

 multitude of friendly fellow laborers. Ne- 

 cessarily because of the astonishing increase 

 in the literature of Surface Geology, many 

 important contributions are unnoticed. He 

 does not profess' to write the historj- of the 

 rise and progress of glacial geologj', but 

 simply to sketch its present position. No- 

 where, he says, has glacial geology been 

 more activelj' prosecuted in recent j'ears 

 than in America. While he has endeavored 

 to keep abreast of this, he preferred to have 

 a summarj' of the American evidence pre- 

 pared by a recognized authority ; and hence 

 called ui>on Professor T. C. Chamberlin, of 

 Chicago, to furnish him with a digest of this 

 material ; which is of great service to every- 



one, since we have been awaiting almost with 

 impatience the announcement of some gen- 

 eral statements here first presented to the 

 public. Professor Geikie also expresses liis 

 great gratification that his conclusions 

 should essentially agree with those of Pro- 

 fessor Penck, of Vienna, in respect to the 

 glacial phenomena of the Alpine lands, the 

 Pj-renees and Auvergne. 



The following is a summary of the glacial 

 succession in Europe as determined by Pro- 

 fessor Geikie fi-om a consideration of all the 

 facts : 



1. Older Pliocene. — Before the advent of 

 the cold the sea occupied considerable tracts 

 in the east and south of England, in Belgium, 

 Holland, northern and western France and 

 the coast lands of the Mediterranean, and 

 boreal forms are just beginning to make 

 their appearance. 



2. Newer Pliocene — Fird Glacial Epoch. — 

 The Weyboum crag and Chillesford clay of 

 England with their pronounced arctic fauna 

 represent a part of the evidence for this time 

 of cold ; also the bottom moraine near the 

 Baltic sea, in southern Sweden, where the 

 movement was from the southeast to the 

 northwest. Arctic animal remains have 

 also been detected in East Prussia at a 

 similar horizon. Hence it is suggested tliat 

 a gigantic glacier occupied the basin of the 

 Baltic sea, and the mountainous parts of 

 Scandinavia and the British Isles were snow 

 clad. In the Alps the snow line was de- 

 pressed for 4,000 feet or so below its present 

 level, and all the great mountain valleys 

 were filled with glaciers which left behind 

 terminal moraines at the foot of the chain. 

 In central France verj- considerable glaciers 

 descended from the great volcanic cones of 

 Auvergne and Cantal. 



3. First Interglacial Epoch. Latest Plio- 

 cene. Forest Bed of Cromer. — The arctic 

 fauna retreated from the North Sea. and dry 

 land occupied the southern part of this sea 

 up to the latitude of Norfolk. The river 



