GEOLOGY: J. BARRELL 
499 
beyond what was laid down by the rivers in time of flood to maintain 
their grade across the sinking basins was carried through to the shallow 
sea which lay on the surface of the continent to the southwest. The 
relations were somewhat similar to those which now prevail between 
the ranges of the North American Cordillera and the Tertiary basins 
which lay between them and especially on the west between the Sierra 
Cascade chains and the Coast Ranges. The Great Valley of Califor- 
nia may therefore in the present epoch, both in physiography and in 
climate be cited as a striking illustration of the nature of the Old Red 
Sandstone basins. 
iMacnair and Reid, Geol. Mag. Decade IV, 3, 106-116, 217-221 (1896). 
2 Goodchild, J. G., The Older Deutozoic Rocks of North Britain, Geol. Mag. Decadz V, 
1, 591-602 (1904). 
3 Walther, J., Geschichte der Erde mid des Lebens, 259 (1908). 
4 Barrell, J., Relative Geological Importance of Continental, Littoral, and Marine Sedi- 
mentation, /. Geol., 14, 316-356, 430-457, 524-568 (1906); Relations Between Climate and 
Terrestrial Deposits, Ibid., 16, 159-190, 255-295, 363-384 (J 908). 
5 Barrell, J., The Upper Devonian Delta of the Appalachian Geosyncline, Amer. J. ScL, 
36, 429-472 (1913), 37, 87-109, 225-253 (1914). 
^ This paper was given in brief form at the meeting of the American Society of Verte- 
brate Paleontology at New Haven, Conn., on December 26, 1907 [Loomis, F. B., Report 
of the Secretary, The American Society of Vertebrate Paleontology, Science, 27, 254 (1908)], 
and more fully at the meeting of the Geological Society of America at Washington, Decem- 
ber 28, 1915. It will be published in full in the Bulletin of the Geological Society of America 
in 1916. The present paper is a digest and its chief importance is because of its bearing 
on the environment of early vertebrates. In that way it is introductory to a paper on the 
Influence of Silurian-Devonian Climates on the Rise of Air-breathing Vertebrates which 
will follow in these Proceedings. 
^ Pirsson-Schuchert, Text Book of Geology, Part II, Historical Geology, by C. Schuchert, 
714-721 (1915). 
THE INFLUENCE OF SILURIAN-DEVONIAN CLIMATES ON THE 
RISE OF AIR-BREATHING VERTEBRATES 
By Joseph Barrell 
DEPARTMENT OF GEOLOGY. YALE UNIVERSITY 
Received by the Academy. July 17. 1916 
The problems of organic evolution have many aspects and ramify 
into many fields of science. The subject was at first embraced chiefly 
in the domain of the old time naturalist — zoologist or botanist. But 
the problems of variation and heredity have passed into the hands of the 
experimental evolutionist; and there are other problems whose answers 
are found in the geologic record — but these are of two rather opposite 
aspects. On the one hand, the paleontologist specializes particularly 
