CONTENTS 
Page 
Physiology. — Some Physical Characteristics of the Ear . By J. P. Mint on 221 
Genetics. — Non- Disjunction and the Chromosome Relationships of Droso- 
phila willistoni By R. C. Lancefield and C. W. Metz 225 
Chemistry. — An Apparatus for Determination of the Gases in Blood and 
Other Solutions . By D. D. Van Slyke 229 
Paleontology. — Adaptive Radiation and Classification of the Probos- 
cidea . . ' . . By H. F. Osborn 231 
Genetics. — A Case of Rearrangement of Genes in Drosophila .... 
By A . H. Sturtevant 235 
Physics. — A Remeasurement of the Radiation Constant, h, by Means of 
X-Rays . . , By W. Duane, H. H. Palmer, and Chi-Sun Yeh 237 
Physics. — The U-Tube Absolute Electrometer By C. Barus 242 
Mathematics. — Geometric Aspects of the Abelian Modular Functions of 
Genus Four (I) ..... By A. B. Coble 245 
Mineralogy. — Melanovanadite, A New Mineral from Mina Ragra, Pasco, 
Peru By W. Lindgren 249 
Editorial Note 251 
