(Continued from page 3 of cover.) 



VOLUME 57. 



1. Kent, Nobton A., and Ta.yi.or, Lucien B. — The Grid Structure in Echelon Spectrum 



Lines, pp. 1-18. December, 1921. $.75. 



2. LoTKA, Alfred J. — The General Conditions of Validity of the Principle of Le Chatelier. 



pp. 19-37. January, 1922. $.75. 



3. Bridgman, p. W. — The Effect of Tension on the Electrical Resistance of Certain Ab- 



normal Metals, pp. 39-66. April, 1922. $1.00. 



4. Bell, Louis. — Notes on the Early Evolution of the ReQector. pp. 67-74. February, 



1922. $.50. 



5. Bridgman, P. W. — The Effect of Pressure on the Thermal Conductivity of Metals, pp. 



75-127. April, 1922. $1.25. 



6. Bridgman, P. W. — The Failure of Ohm's Law in Gold and Silver at High Current Densities. 



pp. 129-172. April, 1922. $1.25. 



7. Pierce, George W. — A Table and Method of Computation of Electric Wave Propagation, 



Transmission Line Phenomena, Optical Refraction, and Inverse Hyperbolic Functions of 

 a Complex Variable, pp. 173-191. April, 1922. $1.25. 



8. Pierce, George W. — Artificial Electric Lines with Mutual Inductance between Adjacent 



Series Elements, pp. 193-212. May, 1922. $1.25. 



9. Barker, Franklin D. — The Parasitic Worms of the Animals of Bermuda. I. Trema- 



todes. pp. 213-237. 3 pis. May, 1922. S.65. 



10. Bennitt, Rudolf. — Additions to the Hydroid Fauna of the Bermudas, pp. 239-259. 



May, 1922. $.65, 



11. Brues, Charles T. — Some Hymenopterous Parasites of Lignicolous Itonididfe. pp, 261- 



288. 2 pis. May, 1922. $.85. 



12. Thaxter, Roland. — A Revision of the Endogoneae. pp. 289-350. 4 pis. June, 1922. 



$1.25. 



13. Clark, H. L. — The Echinoderms of the Challenger Bank, Bermuda, pp. 351-362. 



1 pi. June, 1922. $.50. 



