140 



SCIENCE 



[N. S. Vol. L. No. 1284 



the forward thrust which always accompanied 

 his rising at the bottom of the swing. 



Henry Ceew 

 July 11, 1919 



SCIENTIFIC BOOKS 



The Evolution of the Earth and its Inhabi- 

 tants. A series of Lectures Delivered be- 

 fore the Tale Chapter of the Sigma Xi 

 during the Academic Year 1916-1917, by 

 Joseph Baerell, Charles Schuchert, Lor- 

 ANDE Loss Woodruff, Richard Swan Lull, 

 Ellsworth Huntington. New Haven, Tale 

 University Press. 1918. 

 This volume of essays prepared at the sug- 

 gestion of Professor Lull, as president of the 

 Yale Sigma Xi, is an interesting and imique 

 addition to the literature of the subject. Each 

 lecture is a separate essay, the preparation of 

 which involved considerable time, thought and 

 original work. The first lecture by Joseph 

 Barrell, whose loss too early in life we all 

 mourn, is entitled : " The Origin of the 

 Earth." It was especially fitting that Pro- 

 fessor Barrell should give this lecture since 

 his work on the age of the earth had drawn 

 him into close touch with the astronomical 

 and mathematical work involved in the prob- 

 lem of the earth's origin. The lecture reviews 

 the various attempts to explain the origin of 

 the earth, giving chief attention to the plane- 

 tesimal hypothesis. The phase of the work on 

 which Professor Barrell's own work bears is 

 to be found in his discussion of " The Origin 

 of Ocean Basins," " The Eeign of Surface 

 Processes and Beginning of the Archean." 

 He closes his lecture with the thought: 



It is not known how close they (oldest Archean 

 rocks) stand in point of time to the formative 

 processes whose description has been attempted. 

 With these oldest rocka, the dimly known, heroic 

 and mythical eon of the earth is closed and the first 

 historic eon opens as the remote and long endur- 

 ing division of geologic time. 



Professor Schuchert's lecture " The Earth's 

 Changing Surface and Climate during Geo- 

 logic Time " reviews in part the lecture of 

 Professor Barrell pointing out the climatic 

 features involved and extending Barrell's ob- 



servations into the known periods of geologic 

 history. The fundamental factor in climate 

 is atmosphere, and Professor Schuchert's dis- 

 cussion of the " Origin of the Atmosphere " 

 opens the problems of " Climates of the Past " 

 which he is able to discuss so well because 

 of his extensive studies in paleontology and 

 paleogeography. 



The "Origin of the Earth's Waters," 

 " Source of the Salts of the Ocean " and 

 " Origin of the Sedimentary Strata " give the 

 reader the most modern ideas of these funda- 

 mental aspects of geology and lead up to the 

 discussion of the changes in surface features 

 which the earth, has experienced in its evolu- 

 tion from a primordial mass to the recent. 

 The discussion is accompanied by maps and 

 tables explaining in a graphic way the 

 thoughts of the lecture. Professor Schuchert 

 is inclined to the view that geologic time has 

 endured about 800 million years, supporting 

 the ideas of Matthew, Shapley and Barrell 

 from other evidences. 



Professor Woodruff in his lecture on " The 

 Origin of Life " has attacked a much more 

 difficult problem because of the great dearth 

 of evidence or analogy. He has handled the 

 difficult task cleverly in discussing, first the 

 nature of protoplasm, the individuality of 

 organisms, and by giving an interesting his- 

 torical account of "The Theories of the Origin 

 of Life " under the following titles : " Vital- 

 ism," " Cosmozoa Theory," " PfliigeT's Theory," 

 "Moore's Theory," "Allen's Theory," " Tro- 

 lands Enzyme Theory," " Osborn's Theories." 

 It is rather disappointing to have Huxley and 

 Darwin close this lecture, since it would have 

 been extremely pleasing to know what Wood- 

 ruff himself thinks about the " Origin of Life," 

 and his research work has certainly given him 

 some idea on this interesting topic. 



No one could speak with more knowledge of 

 facts as to the " Pulse of Life " than Pro- 

 fessor Lull in the fourth lecture. 



The stream of life ilows so slowly that the 

 imagination fails to grasp the immensity of time 

 required for its passage, but like many another 

 stream, it pulses as it flows. There are times of 

 quickening, the expression points of evolution, and 



