234 Scientific Intelligence. 



lie shows that Gibbs's phase rule applies to these, as well as to 

 igneous rocks, and draws some interesting conclusions, which 

 help in the scheme of classification adopted. The petrographical 

 part closes with a description of the various types, of pneumato- 

 lytic varieties and of ores, etc. 



The last part of the volume, consisting of about 250 pages, is 

 devoted to a careful and thorough study of the minerals appear- 

 ing in the contact zone; in round numbers some 90 species being 

 considered. These are treated from crystallographies, chemical, 

 optical, and genetic standpoints, the whole forming a notable 

 contribution to mineralogy, especially of the region under con- 

 sideration. In conclusion, it may be remarked that this work 

 should be in every geological reference library, and will repay 

 reading by the petrographer, mineralogist and student of the 

 genesis of ore deposition. l. v. p. 



4. GrundziXge der Paldontologie (Paldozooloc/ie); by Karl A. 

 von Zittel. Part I, Invertebrata reworked by Ferdinand 

 Broili; pp. 607 and 1414 text-figures. Part II, Vertebrata re- 

 worked by Ferdinand Broili, Ernest Koken and Max Schlosser; 

 pp. 598 and 749 text-figures. Munich (R. Oldenbourg), 1911. — 

 This well-known German text-book of Paleontology, the best one 

 on the subject, has been thoroughly revised and brought up to 

 date. The first edition appeared in 1895 in one volume, had 971 

 pages with 2048 text-figures and treated about 6800 genera. The 

 present book in two volumes represents the third edition of the 

 Invertebrata and the second edition of the Vertebrata, has 1205 

 pages with 2163 text-figures, and nearly 10,700 genera are dis- 

 cussed or classified. The first volume was reviewed in the 

 January (1911) number of this Journal. 



The fishes are revised by Professor Koken of Tubingen, and 

 that the work has been well done is shown in the fact that 140 

 pages are devoted to them. Dr. Broili of the Alte Akademie 

 at Munich has revised the Amphibia, while most of the matter 

 treating of the Reptilia he has rewritten. Dr. Schlosser, also of 

 the Alte Akademie, has revised the birds, and in good part 

 rewritten the mammals, which are described on 260 pages. The 

 classification throughout the book is conservative, and yet 

 progressive. 



No paleontologist can work without the book. c. s. 



II. Miscellaneous Scientific Intelligence. 



1. Les Sommes des Pifrm.es Puissances Distinctes Egales 

 d une Pi&me Puissances ; by Edouard Barbette. Pp. 153. 

 Paris (Gauthier-Villars).— This treatise, as indicated by the title, 

 discusses a generalization of Fermat's theorem, viz., the determi- 

 nation of the necessary and sufficient conditions for a sum of dis- 

 tinct pth powers to be equal to a pXk power, p being any integer. 

 The main topic suggests three subsidiary problems formulated by 

 the author as follows : 



