Geology. ^^^ 



The major portion of the book is taken up with a discussion of 

 the speculations of the metaphysicians on the meaning of move- 

 ment from the days of Zeno and Aristotle down to recent times. 

 Although the author's treatment is historical in the main, he fails 

 to give Lorentz and Larmor the great credit which they deserve 

 for the theoretical development whose only logical outcome was 

 Einstein's principle of relativity. The author has a chapter 

 entitled ''In what Sense is the Universe Infinite," but he does 

 not mention Einstein's and De Sitter's interesting speculations 

 on a re-entrant universe. The book is of more interest to pro- 

 fessional philosophers than to physicists or mathematicians. 



L. p. 



II. Geology. 



1. Zur Alteren GescJiichte des Diskoniinuitdisprollems in der 

 Biogeographie; by Nils von Hofstex. Zoolog. Annalen, 7, 197- 

 353. 1916. — This essay on the theories of the variable distribution 

 of plants and animals is limited to the living world, and does not 

 consider the life of the past ages. The presentation is clearly and 

 interestingly written by a biologist along historical _ lines. It 

 begins with'the theories of the Greeks as set forth by Hippocrates 

 and Aristotle, who thought the distribution to be due to differ- 

 ences in the local climates, and follows the more essential ideas 

 down to the present time. For a while the church stimulated this 

 research because of the riddle of the wide distribution and varia- 

 bility of man, but in the end it fought the conclusions of the 

 naturalists. 



Modern vicAvs began with the discovery of America, with its 

 plants and animals which are different from those of Europe. 

 Some continued to explain this difference by special local crea- 

 tions, and in fact Louis Agassiz (1850-1859) held to the creation 

 theory to the end of his life. Buff on (1749-1756) is sometimes 

 regarded as the originator of modern views in regard to bio- 

 geographv. The wav was further indicated by Cuvier (1815), 

 Lyell (1830-1833), Heer (1845), and Forbes (1846), and modern- 

 ized b}^ Hooker, De Candolle, Darwin, and Wallace. Now we 

 know that the organisms are where they are because of local 

 genetic developments out of antecedent stocks, conditioned by 

 their variable dispersion and evolution along varying routes of 

 travel and climate, and that this variation was brought about in 

 the main by the geologic changes in the configuration of the land 

 surfaces and their oceanic boundaries. c. s. 



2. Recent Molluscs of the Gulf of Mexico and Pleistocene and 

 Pliocene Species from the Gulf States. Part I: Pelecypoda; by 

 Carlotta J. Maury. Bull. Amer. Paleontology, vol. 8, No. 34, 

 113 pp., 1 pi., 1920. — This is an annotated bibliography, with 

 synonyms, of 345 forms of pelecypods, as limited by the title, 

 along with their distribution and occurrence in the Gulf coast 

 area. Only one new species is described. c. s. 



