CONTENTS 
v 
CHEMISTRY 
The Heat Capacity of Electro-Positive Metals and the Thermal Energy of 
Free Electrons By Gilbert N. Lewis, E. D. Eastman and W. H. Rodebush 25 
Notes on Isotopic Lead By Frank Wigglesworth Clarke 181 
Refractive Index and Solubilities of the Nitrates of Lead Isotopes 
By Theodore W. Richards and Walter C. Schumb 386 
The Purification by Sublimation and the Analysis of Gallium Chloride 
By Theodore W. Richards, W. M. Craig, and J. Sameshima 387 
The Purification of Gallium by Electrolysis, and the Compressibility and 
Density of Gallium By Theodore W. Richards and Sylvester Boyer 388 
GEOLOGY AND PALEONTOLOGY 
The Study of the Sediments as an Aid to the Earth Historian 
By Eliot Blackwelder 163 
Fringing Reefs of the Philippine Islands By W. M. Davis 197 
Glacial Depression and Post-Glacial Uplift of Northeastern America 
By H. L. Fair child 229 
Metalliferous Laterite in New Caledonia By W. M. Davis 21 S 
The Importance of Nivation as an Erosive Factor, and of Soil Flow as a Trans- 
porting Agency, in Northern Greenland ByW. Elmer Ekblaw 288 
The Phylogeny of the Acorn Barnacles By Rudolf Ruedemann 382 
Possible Derivation of the Lepadid Barnacles from the Phyllopods 
By John M. Clarke 384 
MINERALOGY AND PETROLOGY 
A Contribution to the Petrography of the South Sea Islands 
By J. P. Iddings and E. W. Morley 110 
Tests for Fluorine and Tin in Meteorites with Notes on Maskelynite and 
the Effect of Dry Heat on Meteoric Stones By George P. Merrill 176 
BOTANY 
Dynamical Aspects of Photosynthesis By W.J. V. Osterhout and A.R.C. Haas 85 
The Taxonomic Position of the Genus Actinomyces By Charles Drechsler 221 
A Bacteriological Study of the Soil of Loggerhead Key, Tortugas, Florida 
By C. B. Lipman and D. D. Way nick 232 
ZOOLOGY 
The Reactions of the Melanophores of Amiurus to Light and to Adrenalin 
By A . W. L. Bray 58 
Further Experiments on the Sex of Parthenogenetic Frogs.. By Jacques Loeb 60 
Possible Action of the Sex-Determining Mechanism By C.E. McClung 160 
The Growth of the Alaskan Fur Seal Herd Between 1912 and 1917 
By G. H. Parker 168 
Autonomous Responses of the Labial Palps of Anodonta By P. H. Cobb 234 
The Myodome and Trigemino-Facialis Chamber of Fishes and the Correspond- 
ing Cavities in Higher Vertebrates By Edward Phelps Allis, Jr. 241 
Variation and Heredity During the Vegetative Reproduction of Arcella 
Dentata By R.W Hegner 283 
