June 27, 1919] 



SCIENCE 



607 



deltas and geographies of the geologic past 

 may be discerned in the sediments or stratified 

 rocks that make up the greater portion of the 

 geologic record. This work brings out espe- 

 cially the importance in earth history of the 

 ancient formations laid down upon the lands 

 by the fresh waters and the wind, in con- 

 tradistinction to those deposited by the seas 

 and oceans. 



The length of geologic time was another 

 problem that deeply interested Barrell. In his 

 " Ehythms and the Measurements of Geologic 

 Time," he came to the conclusion that through 

 the rhythmic oscillations of the terrestrial 

 processes which the earth has undergone, its 

 age is many times greater than even geologists 

 in general have imagined — in fact, that it is 

 of the order of about 1,500 million years. 



A fourth line of research which occupied 

 Barrell was the origin and genesis of the 

 earth, and here he extended in modified form 

 the Chamberlin-Moulton planetesimal hypothe- 

 sis, t. e., that the planets and their moons 

 arose out of the sun during a time of induced 

 tidal disruption. Some of his best work was 

 to develop along this line, and an extensive 

 manuscript on " The Genesis of the Earth " is 

 ready for publication. 



Since 1913, Barrell has on a number of oc- 

 casions taken opportimity to point out that 

 the supposed Mesozoic peneplain of southern 

 New England was in reality " stairlike or ter- 

 raced in its character, facing the sea, and 

 bore the marks of ultimate control by marine 

 denudation. These terraces [more than five 

 in number] are now dismantled by erosion ex- 

 cept in regions favored by the presence of 

 broadly developed resistant rock structures. 

 . . . All are regarded as younger than the 

 Miocene." With this view, he adds, we get 

 " a suggestion of the geological rapidity of 

 completion of an erosion cycle in a region 

 near the sea and of a sequence of diastrophic 

 rhythms there recorded." Here too there is 

 considerable manuscript that will be published 

 later on. 



Finally, the evolutionary problems con- 

 nected with paleontology claimed his interest, 

 and he has presented evidence to show that 

 fishes probably arose in the early Paleozoic in 



the fresh waters of the lands, and thence 

 migrated to the seas. Also that lungs devel- 

 oped out of air-bladders in water-breathing 

 animals caught in recurrent epochs of semi- 

 aridity. Such great environmental changes 

 brought about the necessity for change from 

 a water habitat to seasonal dry ones, and 

 hence " the piscine faima which endured these 

 conditions came through profoundly changed." 

 The primitive sharks of Silurian time, having 

 no air-bladder, " were driven to the seas. The 

 fresh-water fishes which remained were ganoids 

 and dipnoans, fishes with air-bladders efiicient 

 for the direct use of air." Finally, from cross- 

 opterygian ganoids, under the stimulus of the 

 semiaridity of the Devonian, there emerged 

 the amphibians, able to carry forward their 

 activities as terrestrial animals. 



Similarly, ho held that man was brought 

 to his present high physical and mental state 

 not merely as the " product of time and life," 

 but that he is " peculiarly a child of the earth 

 and is born of her vicissitudes." The chang- 

 ing climates during the Pliocene and Pleisto- 

 cene, acting upon the vegetation of these 

 times, caused the prevalent forests of Asia, he 

 thinks, to dwindle away, producing " a rigor- 

 ous natural selection which transformed an 

 ape, largely arboreal and frugivorous in habits, 

 into a powerful, terrestrial, bipedal primate, 

 largely carnivorous in habit, banding together 

 in the struggle for existence, and by that 

 means achieving success in chase and war. 

 The gradual elimination, first of the food of 

 the forests, lastly of the refuge of the trees, 

 through increasing semiariditj', would have 

 been a compelling cause as mandatory as the 

 semiaridity which compelled the emergence of 

 vertebrates from the waters, transforming 

 fishes into amphibians." 



Charles Schuchert 



Tale Universitt 



SCIENTIFIC EVENTS 



THE SOLAR ECLIPSE' 



Telegrams received by the Astronomer 

 Royal report that at the station at Sobral, in 

 Brazil, occupied by Dr. Crommelin and Mr. 



» From Mature. 



