CONTENTS 
Page 
Physiology. — Heliotropic Animals as Photometers on the Basis of the Validity 
OF THE BUNSEN-ROSCOE Law FOR HeLIOTROPIC REACTIONS 
By Jacques Loeb and John H. Narthrop 539 
Zoology. — The Appearance of Reverse Mutations in the Bar-Eyed Race of 
Drosophila Under Experimental Control By H. G. May 544 
Zoology. — The Part Played by Alcyonaria in the Formation of Some Pacific 
Coral Reefs By Lewis R. Gary 545 
Oceanography. — Observations Upon the Alkalinity of the Surface Water of 
the Tropical Pacific By Alfred Goldshorough Mayer 548 
Zoology. — The Effect of Temperature on Linkage in the Second Chromosome 
of Drosophila By Harold R. Plough 553 
Zoology. — Genetic Factors Affecting the Strength of Linkage in Drosophila 
By A. H. Sturtevant 555 
Astronomy. — Further Evidence on the Concentration of the Stars Toward 
the Galaxy . . ; By Frederick H. Seares 558 
Physics. — Theoretical Relations in the Interferometry of Small Angles . 
By Carl Barus 563 
Genetics. — Inter-Periodic Correlation in the Egg Production of the Domes- 
tic Fowl . . . By J. Arthur Harris, A. F. Blakeslee, and Wm. F. Kirkpatrick 565 
Chemistry. — Two Laws Governing the Ionization of Strong Electrolytes in 
Dilute Solutions and a New Rule for Determining Equivalent Con- 
ductance AT Infinite Dilution Derived from Conductivity Measurements 
with Extremely Diluted Solutions of Potassium Chlorite 
• By Edward W. Washburn 569 
Genetics. — On the Growth and Fecundity of Alcoholized Rats 
By E. G. MacDowell and E. M. Vicari 577 
National Research Council, Minutes of the Meeting of the National 
Research Council Held on Thursday, April 19, 1917, in Rooms 42 and 43 
of the United States National Museum, Washington, D. C 580 
Meetings of the Executive Committee 
582 
