138 



SCIENCE 



[N. S. Vol. XL. No. 1021 



parts, such, for example, as that on subaquatic 

 gliding of sediments, are novel, are well 

 treated, and valuable for their bearings on the 

 origin of certain structures and relations of 

 stratified rocks. 



The next section of 187 pages deals with 

 the biosphere. There is given a classification 

 of the organic kingdom and the relations of 

 each group to its environment. The principles 

 which control the geographic distribution of 

 animals are also set forth. 



A final section deals with the principles of 

 classification and correlation of geologic 

 formations. 



One of the most valuable features of the 

 volume consists of the bibliographies which 

 are given at the end of each chapter and the 

 frequent references to the more important 

 papers on each subject. The work thus is a 

 guide to the student for his independent 

 navigation and exploration upon that ever- 

 broadening and rising" ocean of literature 

 which threatens to drown research. 



From this statement of contents it is seen 

 that the work is a notable contribution. 

 Every geologist dealing with stratigraphic or 

 historical geology should give it a place in 

 that elect reference shelf, the revolving book 

 case within reach of his ofiice chair. 



To prove that this eulogistic review is the 

 result of a judicial study of the volume it is 

 necessary, however, to supplement the previous 

 statements by finding something for adverse 

 comment, even if only of minor importance. 



A good deal of space has been given to the 

 discussion of secondary structures — faults, 

 folds, metamorphism, igneous intrusion, etc. 

 This has added to the bulkiness and cost of 

 the' volume without adding proportionately to 

 an increase in its value. Thisgreater cost wiU 

 tend to keep it on the reference shelves of li- 

 braries instead of installing it in the private 

 library of every student. The book is conse- 

 quently likely to have less infiuence than if 

 the detailed discussion of secondary structures 

 had been ruled out or published as a separate 

 volume. The subject matter does not appear 

 sufficiently essential for the principles of 

 stratigraphy to require incorporation, and a 



comprehensive study of these fields requires 

 furthermore the study of other treatises, such 

 as those of J. Geikie, Van Hise and Leith. 



Classification is necessary in order to deal 

 with the subject-matter of science, and classi- 

 fication must grow with the growth of knowl- 

 edge. One of the noteworthy features of the 

 work is the development of systematic classifi- 

 cation to cover the field of sedimentation and 

 stratigraphy. It aids in a logical and precise 

 treatment, but the reviewer thinks that the 

 author may have partially hindered his pur- 

 pose by an over-classification and the extensive 

 coinage of unfamiliar Greek names. Such 

 words as caustobioliths and sapropelcalcilyths 

 are examples. The renaming of contact meta- 

 morphism as SBthoballism and dynamic meta- 

 morphism as symphrattism seems unnecessary 

 and is hardly likely to succeed. To discuss 

 earthquakes under the division of the eentro- 

 sphere seems also quite inappropriate. " The 

 littoral" in its original meaning and as used 

 by a number of geologists has been restricted 

 to the zone of shore between high and low tide. 

 The stratigraphic characters are unique in 

 that they receive the impress of alternate ex- 

 posure to the air and sea. This dual relation 

 must be recognized in order to avoid the in- 

 herited confusion between continental and ma- 

 rine deposits. The reviewer regards it as un- 

 fortunate, therefore, to extend it as a general 

 term as is here done to cover all that region 

 from the high-tide line to the edge of the con- 

 tinental shelf. This in some regions is more 

 than 100 miles from the shore and in ancient 

 times was often vastly farther. On the other 

 hand, however, it should be noted that the re- 

 finement of classification adds greatly to the 

 analysis of the original structure and litho- 

 genesis of the continental sediments, divided 

 under the heads of atmoclastic, anemoelastic 

 and hydroclastic rocks, assisting in a better 

 presentation of these groups than has hereto- 

 fore appeared. 



An enumeration and discussion of the mul- 

 tiple hypotheses which may participate in com- 

 plex processes is of great value to the advanced 

 student, opening his mind to various possi- 

 bilities and stimulating his imagination to 



