CONTENTS 
Page 
Genetics. — Hereditary Tendency to Form Nerve Tumors 
By C. V. Davenport 213 
Mathematics. — Arithmetical Theory of Certain Hurwttzian Continued Frac- 
tions % .... By D.N. Lehmer 214 
Mathematics. — On Closed Curves Described by a Spherical Pendulum . . 
By Arnold Emch 218 
Botany. — The Taxonomic Position of the Genus Actinomyces 
By Charles Drechsler 221 
Astronomy. — Studies of Magnitudes in Star Clusters, VIII. A Summary of 
Results Bearing on the Structure of the Sidereal Universe .... 
By Harlow Shapley 224 
Geology. — Glacial Depression and Post-Glacial Uplift of Northeastern 
America . By H. L. Fair child 229 
Botany. — A Bacteriological Study of the Soil of Loggerhead Key, Tortugas, 
Florida By C. B. Lipman and D. D. Waynick 232 
Zoology. — Autonomous Responses of the Labial Palps of Anodonta .... 
By P. H. Cobb 234 
Physics. — The Depth of the Effective Plane in X-Ray Crystal Penetration 
By F. C. Blake 236 
Zoology. — The Myodome and Trigemino-Facialis Chamber of Fishes and the 
Corresponding Cavities in Higher Vertebrates By Edward Phelps Allis, Jr. 241 
Genetics. — The Effect of Inbreeding and Crossbreeding Upon Development 
By D. F. Jones 246 
National Research Council, Executive Order Issued by the President of 
the United States, May 11, 1918 251 
— — , Minutes of the Second Meeting of the Executive Board of the 
War Organization in Joint Session with the Council of the National 
Academy of Sciences 3 252 
, Minutes of Third Meeting of Executive Board of War Organization 256 
, Report of the Annual Meeting 261 
