TABLE OF CONTENTS 
Officers and Members of the Academy, November 19, 1917 x 
Report of the Annual Meeting, April, 1917 390 
Award of Medals 398 
Research Grants from the Trust Funds of the Academy 398 
Notices of Biographical Memoirs 537 
List of Publications of the National Academy of Sciences 743 
Report of the Autumn Meeting, November, 1917 753 
Index 759 
# NATIONAL RESEARCH COUNCIL 
Research Committees in Educational Institutions 223 
Central Committee on Research 226 
Reports of Meetings of the Executive Committee 227, 530, 582, 628, 733 
Membership of the Committees of the Council 317 
Meetings of the Executive Council 438 
Joint Meeting of the Executive, Military, and -Engineering Committees 443 
Suggestions Relating to the New National Army by the Anthropology Com- 
mittee OF THE National Research Council 526 
First Report of Committee on Botany 529 
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 
Scientific Publications from Germany By Paul Brockett 717 
Report of Committee on Geology and Paleontology 721 
First Report of Committee on Zoology 724 
The Scope and Work of the Botanical Raw Products Committee 731 
MATHEMATICS 
Natural and Isogonal Families of Curves on a Surface By Joseph Lipka 78 
Some Problems of Diophantine Approximation: The Series 2 e (Xn) and the 
Distribution of the Points (Kna) By G. H. Hardy and J. E. Littlewood 84 
A Note on the Fitting of Parabolas By John Rice Miner 91 
The Complete Enumeration of Triad Systems in 15 Elements 
By F. N. Cole, Louise D. Cummings and H. S. White 197 
Dynamical Systems with Two Degrees of Freedom By George D. Birkhof 314 
The Cayleyan Curve of the Quartic By Teresa Cohen 447 
Triads of Transformations of Conjugate Systems of Curves 
By Luther Pfahler Eisenhart 453 
On the General Theory of Curved Surfaces and Rectilinear Congruences 
By Gabriel M. Green 587 
A Necessary and Sufficient Condition for the Existence of a Stieltjes 
Integral By Gilbert Ames Bliss 633 
iii 
