REVIEWS 465 



The illustrations are unusually good and are judicially selected; they 

 include eight plates, and numerous illustrations and diagrams in the text. 

 The characteristics of the various types of igneous rocks are well brought 

 out in two tables. While valuable in a descriptive and historical way, 

 many of the more theoretical portions of the book willl be regarded by 

 American students as not entirely in accord with modern notions. This 

 is particularly true of the author's treatment of metamorphism, which 

 is still dominated by the older ideas of a stiff liquid condition during meta- 

 morphism, and into which the newer ideas of the continuance of a rigid 



condition do not enter. 



E. S. B. 



