CONTENTS 
Page 
Mathematics. — The Cayleyan Cukve of the Quartic , . By Teresa Cohen 447 
Astronomy. — Search for an Einstein Relativity- Gravitational Effect in 
THE Sun By Charles E. St. John 450 
Mathematics. — ^Triads of Transformations of Conjugate Systems of Curves 
By Luther Pfahler Eisenhart 453 
Chemistry. — The Molecular Weights of the Tjiiarylmethyls 
By M. Gomberg and C. S. Schoepfle 457 
Zoology. — Sex-Determination, and Sex-Differentiation in Mammals . . . 
By Frank R. Lillie 464 
Physics. — The Crystal Structure of Magnesium . . . . By A. W. Hull 470 
Geology. — The Structure of High-Standing Atolls . . By W. M. Davis 473 
Astronomy. — Studies of Magnitude in Star Clusters, VII. A Method for 
THE Determination of the Relative Distances of Globular Clusters 
By Harlow Shapley 479 
Astronomy. — ^The Principal Axes of Stellar Motion . . By H. Rayrtiond 485 
