CONTENTS 



Page 



Original Papers 



Physical Chemistry. — ^Methods of stating acidity. Edgar T. Wherry and Elliot Q. 



Adams 197 



Physical Chemistry. — ^Reply to Wherry and Adam's article on methods of stating 



acidity. Wm. Mansfield Clark , 199 



Geology. — Scientific by-products of applied geology. George Otis Smith 203 



Zoology. — The steps in the evolution of animals. Austin H. Clark • 207 



Abstracts 



Physics. 209 



Spectroscopy 210 



Proceedings 



■r 



Philosophical Society ^ 211 



Biological Society 213 



Entomological Society ^ 215 



Scientific Notes and News 220 



ADVERTISEMENT 



ThcflAcADEMY has on hand a miscellaneous stock of separates of papers 

 from the Proceedings (1898-1911). By authority of the Board of Man- 

 agers, these papers are offered for sale for a limited period at the reduced 

 prices indicated below. - (Publication of these classified lists was begun on 

 March 4 and will be continued in subsequent numbers of the Journai,.) 



ICHTHYOLOGY 



Allen, William F. Distribution of the lymphatics in the head, and in the dorsal, 



pectoral, and ventral fins of Scorpaenichthys marmoratus. 50 pp., 3 pi $0.20 



Allen, William F. The blood-vascular system of the Loricati, the Mail-cheeked 



Fishes. 131 pp., 6 pi 0.25 



Allen, William F. Distribution of the subcutaneous vessels'in the head region of 



the Ganoids, Polyodon and Lepisosteus. 80 pp., 15 pi 0.25 



Eigenmann, Carl H. On a collection of fishes from Buenos Aires. 10 pp., 3 pi. . 0. 10 



EiGENMANN, Carl H., and Ward, David Perkins. The Gymnotidae. 28 pp., 5 pi. 0. 15 



Gilbert, Charles H. Results of the Branner-Agassiz Expedition to Brazil. No. 

 3. The fishes. 24 pp., 1 pi 0.10 



Heller, Edmund, and Snodgrass, Robert Evans. Papers from the Hopkins- 

 Stanford Galapagos Expedition, 1898-1899. No. 15, New fishes. 41 pp., 19 pi. . 20 



Snodgrass, Robert Evans, and Heller, Edmund. Shore-fishes of the Revil- 



lagigedo, Clipperton, Cocos and Galapagos Islands. 95 pp 0. 15 



The set of 8 ichthyological papers 1 . 00 



This page may be used as an order blank. Send orders with check or stamps to the 

 Corresponding Secretary, Robert B. Sosman, Geophysical Laboratory, Washington, D. C. 



