CONTENTS Page 
Physics. — Th^ Physicai. Examination op Hearing and Binaurai. Aids for the 
Deaf . . . . . By R. L. Wegel 155 
Physics. — The Production of an E. M. F. on Ci^osed Circuit by a Light 
Effect on ArgEntite . . . By H. H. Sheldon and P. H. Geiger 161 
Physics. — Positive and Negative Pinhole Resonators . . By C. Barus 163 
Physics. — The Evaluation of Quantum Integrals . . By P. S. Epstein 166 
Astronomy. — Invisible Sun-Spots By G. E. Hale 168 
Astronomy. — Comparison of Theory with Observation for the Minor 
Planets 10 Hygiea and 175 Andromache with Respect to Perturbations 
BY Jupiter . . By A. 0. Leuschner 170 
Astronomy. — A Method of Deriving the Distance of the A-Type Stars 
By W. S. Adams and A. H. Joy 173 
Astronomy, — The Larger Results of 20 Years of Solar Radiation Ob- 
vSERvations By C.G. Abbot, F. E. Fowle and L. B. Aldrich 177 
Pathology. — Replantation of Entire Limbs without Suture of Vessels 
By W. S. Halstead 18 
Zoology. — Degeneration and Regeneration of the Lateral-line Organs in 
Amiurus Nebulosus - . By M. H. Chambers 186 
Chemistry. — The Isolation of Pyrimidines from the Nucleic Acid of 
Tubercle Bacillus . . . By T. B. Johnson and E. B. Brown 187 
Psychology. — The Relative Sensitivity of the Ear at Different Levels of 
Loudness By D. MacKenzie 188 
Mathematics. — Normal Coordinates for the Geometry of Paths . 
By 0. Veblen 192 
Mathematics. — Principal Directions in a Riemannian Space By J. L. Synge 198 
Mathematics. — Principal Directions in the Einstein Solar Field 
By J.L. Synge 204 
Mathematics. — Fields of Parallel Vectors in the Geometry of Paths 
By L. P. Eisenhart 207 
Biology. — On the Influence of Density of Population Upon the Rate of 
Reproduction in Drosophila . . . By R. Pearl and S. L. Parker 212 
Biology. — Animal Evolution By A. H. Clark 219 
Biology. — The Correlation of Time Units and Climatic Changes in Peat 
Deposits of the United States and Europe . . By A. P. Dachnowski 225 
Physics. — The Spectral Energy Distribution and Opacity of Wire Explo- 
sion Vapors By J. A. Anderson 231 
