REVIEWS. 745 



Text-book of Comparative Geology. By E. Kayser, Ph.D. Translated 

 and edited by Philip Lake. Pp. xii, 426. Swan, Sonnenschein 

 & Co., London. (Macmillan). 



The translation of Dr. Kayser's book is a welcome addition to the 

 literature of geology in English. Its title is fairly definitive. It is an 

 attempt to bring together, or to set in their proper relations, the 

 results of geological investigation conducted in the various parts of 

 the world. The volume is too brief to allow this to be carried out in 

 great detail. The abbreviation has been effected in part by the omis- 

 sion, or by no more than the merest mention, of results reached in 

 extra-European countries. This is particularly true with that part of 

 the volume which deals with the post-Paleozoic formations. While at 

 first thought this might seem to detract from the value of the volume 

 for American students, we think on the whole it is an advantage 

 instead, if omissions were necessary. Data concerning American 

 geology are more easily accessible to American students than data 

 concerning European geology, which this volume measurably supplies. 

 The volume will find its chief use in America as a convenient refer- 

 ence book of European geology, and as such it should be widely dis- 

 tributed. Its abundance of tables, showing the relations of the sub- 

 divisions of the various systems in different countries, so far as they 

 are made out, are especially convenient for general reference. 



At several points in the volume there is a noticeable tendency to 

 make unqualified statements where qualified statements would seem to 

 us better. A case in point is the unqualified denial of the organic 

 character of the Eozoon. It is true in most cases, where positive 

 conclusions are asserted, that they represent the best conclusions of 

 the present day, but in some cases they seem to us to represent prob- 

 able or qualified or tentative conclusions, not demonstrated or abso- 

 lute or final ones. 



All pre-Cambrian rocks are represented as Archean, though the 

 length of Archean time is stated to be so great that the beginning of 

 the Cambrian " may be considered as comparatively a recent event." 

 In spite of this recognition of the importance of the Archean, but 

 fourteen pages are devoted to its consideration. Although different 

 systems are not recognized in the pre-Cambrian rocks, the diversity 

 of origin of different parts of the group is distinctly recognized. The 

 author is inclined to attach less weight to the existence of limestone 

 and graphite in the Archean rocks, as indications of life, than would 



