I 
CONTENTS 
Page 
Astronomy. — The Absorption Spectrum of the Novae . . By W. S. Adams 355 
Mathematics. — On Jacobi's Extension of the Continued Fraction Algorithm 
By D. N. Lehmer 360 
Mathematics. — A Character of Jordan Regions by Properties Having no Refer- 
ence to Thetr Boundaries By Robert L. Moore 364 
Physiology.— A Biometric Study of Human Basal Metabolism 
By J. Arthur Harris and Francis G. Benedict 370 
Genetics. — Sex and Sex Intergrades in Cladocera . . By Arthur M. Banta 373 
Zoology —On the Method of Progression in Polyclads . By W. J. Crozier 379 
Paleontology. — The Phylogeny of the Acorn Barnacles 
By Rudolph Ruedemann 382 
Paleontology. — Possible Derivation of the Lepaddj Barnacles from the 
Phyllopods . . . ' By John M. Clarke 384 
Chemistry. — Refractive Index and Solubilities of the Nitrates of Lead % 
Isotopes By Theodore W. Richards and Walter C. Schumb 386 
Chemistry. — The Purification by Sublimation and the Analysis of Gallium 
Chloride . . By Thodore W. Richards, W. M. Craig, and J. Sameshima 387 
Chemistry. — The Purification of Gallium by Electrolysis, and the Compressi- 
bility and Density of Gallium \ . . . 
By Theodore W. Richards and Sylvester Boyer 388 
Zoology. — The Growth-Rate of Samoan Coral Reefs . By Alfred G. Mayor 390 
Astronomy. — The Distances of Six Planetary Nebulae ' . . 
By Adrian van Maanen 394 
National Research Council. — Minutes of the Meeting of the Executive Board 397 
Index 419 
