CONTENTS 
Page 
Physics. — The Condensation and Evaporation of Gas Molecules 
By Irving Langmuir 141 
Astronomy.— The Ninth Satellite of Jupiter .... By Seth B. Nicholson 147 
Zoology. — ^Aortic Cell Clusters in Vertebrate Embryos . . By H, E, Jordan 149 
Zoology. — Rheotropism of Epinephelus Striatus Bloch . . By Hovey Jordan 157 
Botany. — Studies of the Genus Phytophthora . . • • • By J, Rosenbaum 159 
Physics. — A Possible Function of the Ions in the Electric Conductivity op 
Metals By Edwin H. Hall 163 
Geology.— The Gravimetric Survey of the United States , By William Bowie 171 
Physics. — ^The Magnetization of Iron, Nickel, and Cobalt by Rotation and 
the Nature of the Magnetic Molecule By S,J. Barnett 178 
Physics. — ^The Intensities of X-Rays of the L Series 
By David L. Webster and Harry Clark 181 
Genetics. — The Use of Vasectomized Male Mice as Indicators By C. C. Little 186 
Astronomy. — Photographic Magnitudes of Stars in the Selected Areas of 
Kapteyn By Frederick H. Seares 188 
Anthropology. — ^Archaeology of Mammoth Cave and Vicinity: A Preliminary 
Report By N, C.Nelson 192 
Pathology.— The Production in Dogs of a Pathological Condition Which 
Closely Resembles Human Pellagra 
By Russell H. Chittenden and Frank P, Underhill 195 
Mathematics. — The Complete Enumeration of Triad Systems in 15 Elements 
By F. N, Cole, Louise D. Cummings and E. S. White 197 
Physics. — New Data on the Phosphorescence of Certain Sulphides. (Discuss- 
ing Measurements by Drs. H. E. Howe, H. L. Howes and Percy Hodge) , , 
By Edward L. Nichols 199 
Zoology. — ^The Reactions of the Melanophores of the Horned Toad . . , 
By Alfred C. Redfield 202 
Zoology. — The Coordination of the Melanophore Reactions of the Horned 
Toad By Alfred C. Redfield 204 
Geology. — Petrified Coals and Their Bearing on the Problem of the Origin 
of Coals By Edward C. Jefrey 206 
Zoology. — The Effect of Degree of Injury, Level of Cut and Time Within 
the Regenerative Cycle Upon the Rate of Regeneration 
By Charles Zeleny 211 
Astronomy. — ^Preliminary Note on the Distribution of Stars With Respect to 
the Galactic Plane , By Frederick H. Seares 217 
National Research Council. — Research Committees in Educational Insti- 
tutions 223 
— . Central Committee on Research 226 
. Reports of Meetings of the Executive Committee 227 
