Geology and Mineralogy. 73 



given. The book is essentially a compilation and, as seen from 

 the space assigned to each subject, it is far from being exhaustive. 

 The important results of Hayford, for instance, are summed up on 

 two pages ; no mention is made of the volume published by the 

 Carnegie Institution in 1909 on Fundamental Problems in Geol- 

 ogy. Radium and its relation to the earth occupies but three 

 pages. No mention is made of Chamberlin's hypotheses regard- 

 ing the earth's interior and their relation to deformation. The 

 photographic plates, while making the volume more attractive, 

 are not essential to the text. 



The book fulfils a certain purpose as an introduction to geo- 

 physics, but it should be noted that mathematical treatment has 

 in the past inspired a false confidence in results which were often 

 based on incomplete or uncertain premises. It seems, therefore, 

 that such an introductory view should give a much larger space 

 to multiple hypotheses and their geological and quantitative 

 probability, indicating the lines of mathematical analysis which 

 will further test such hypotheses or add to their fertility of results. 



J. B. 



8. The Geological Survey of Sweden. — The Swedish Geologi- 

 cal Survey, which has always been active in its work and publica- 

 tions, has recently issued a series of important papers. These 

 include three quarto volumes : The first series (Ca, No. 4) gives 

 an account of the late Quaternary history of Gottland, by 

 H. Munthe, with numerous striking illustrations. A second (Ca, 

 No. 5) contains a series of papers by different authors, discussing 

 the glaciers of Sweden in the year 1908, with twenty-six plates. 

 The third (Ca, No. 7), by A. Gavelin and A. G. Hogbom, describes 

 the ice seas which occupied extended areas in the mountain 

 region of Sweden at the end of the Ice Age. Several geological 

 maps have also been issued, and further Year-Book No. 3 for 

 1909, containing eleven papers on various subjects by different 

 authors. The first of these treats of the climate of Sweden in the 

 late Quaternary period, by G. Andersson. 



9. The Fossils and Stratigraphy of the Middle Devonic of 

 Wisconsin • by Herb-man F. Cleland. Bulletin XXI, Wisconsin 

 Geological and Natural History Survey, pages i-vi, 1-222, and 53 

 plates, 1911. — In this handsome volume Professor Cleland brings 

 together all that is known in regard to the geology and fauna of 

 the rather local impure dolomites known as the Milwaukee for- 

 mation and correlated by the author with the upper part of the 

 New York Hamilton. More than 200 species of invertebrates 

 and fishes are discussed and illustrated, of which about 40 are 

 described as new. The life assemblage clearly indicates a mix- 

 ture of eastern and western faunas, and proves that " Southern 

 Wisconsin was in the path of migration" between these two inte- 

 rior seas. " Some time before the close of the Hamilton commu- 

 nication was established between the Wisconsin and Iowan areas, 

 in consequence of which we find at Milwaukee a mingling of 

 Cedar Valley forms from the southwest and a modified post- 



