CONTENTS. 



Paoe. 



I. The Grid Structure in Echelon Spectrum Lines. By N. A. Kent 



AND L. B. Taylor 1 



II. The General Conditions of Validity of the Principle of Le Chatelier. 



By a. J. LoTKA 19 



III. The Effect of Tension on the Electrical Resistance of Certain Ab- 



normal Metals. By P. W. Bridgman 39 



IV. Notes on the Early Evolution of the Reflector. ByLouisBell . . 67 



V. The Effect of Pressure on the Thermal Conductivity of Metals. By 



P. W. Bridgman 75 



VI. The Failure of Ohm's Law in Gold and Silver at High Current 



Densities. By P. W. Bridgman 129 



VII. A Table and Method of Computation of Electric Wave Propagation, 

 Transmission Line Phenomena, Optical Refraction, and Inverse 

 Hyperbolic Functions of a Comple.v Variable. By G. W. 

 Pierce 173 



VIII. Artificial Electric Lines with Mutual Inductance between Adjacent 



Series Elements. By G. W. Pierce 193 



IX. The Parasitic Worms of the Animals of Bermuda. I. Trematodes. 



By F. D. Barker 213 



X. Additions to the Hydroid Fauna of the Bermudas. By Rudolf 



Bennitt 239 



XI. Some Hymenopterous Parasites of Lignicolous Itonididae. By 



C. T. Brues 261 



XII. A Revision of the Endogoneae. By Roland Thaxter .... 289 



XIII. The Echinoderms of the Challenger Bank, Bermuda. By H. L. 



Clark 351 



XIV. Atmospheric Attenuation of Ultra-Violet Light. By E. R. 



SCHAEFFER 363 



XV. The Ratio of the Calorie at 72° to that at 20°. By Arnold Rom- 

 berg 375 



XVI. Stiidies on Insect Spermatogenesis. IV. The Phenomenon of Poly- 

 inegaly in the Sperm Cells of the Family Pentatomidoe. By R. 

 H. Bowen 388 



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