( Continued from page 3 of cover.) 



VOLUME 58. 



1. Ames, A. Jr., Proctor, C. A., and Ames, Blanche. — Vision and the Technique of Art. 



pp. 1-47. 23 pis. February, 1923. S3.75. 



2. Birkhoff, George D. and Langer, Rudolph E. — The Boundary Problems and Develop- 



ments Associated with a System of Ordinary Linear Differential Equations of the First 

 Order, pp. 49-128. April. 1923. $3.15. 



3. Vatnio, Edward A. — Lichenes in Insula Trinidad a Professore R. Thaxter Collecti. 



pp. 129-147. January, 1923. $1.00. 



4. Bridgman, P. W. — The Effect of Pressure on the Electrical Resistance of Cobalt, Alumi- 



num, Nickel, Uranium, and Caesium, pp. 149-161. January, 1923. $.75. 



5. Bridgman, P. W. — The Compressibility of Thirty Metals as a Function of Pressure and 



Temperature, pp. 163-242. January, 1923. $1.70. 



6. Baxter, Gregory P., Weatherill, Philip F. and Scripture, Edward W., Jr. — A 



Revision of the Atomic Weight of Silicon. The Analysis of Silicon Tetrachloride and 

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 7 Evans, Alexander W . — The Chilean Species of Metzgeria. pp. 269—324. March, 

 1923 $1.25. 



8. Brues, Charles T. — Some New Fossil Parasitic Hymenoptera from Baltic Amber. 



pp. 325-316. March, 1923. S.65. 



9. Kennelly, A. E. — Text of the Charter of the Academie Royale de Belgique, Trans- 



lated from the Original in the Archives of the Academie at Brussels, pp. 347-351. 

 April, 1923. $.40. 



10. Hitchcock, Frank L. — On Double Polyadics, with Application to the Linear Matrix 



Equation, pp. 353-395. May, 1913. SI. 15. 



11. Hitchcock, Frank L. — Identities Satisfied by Algebraic Point Functions in N-Space. 



pp. 397-421. May, 1923. $.85. 



12. Swan, Clifford M. — The Minimum Audible Intensity of Sound, pp. 423—441. 



May, 1923. $.75. 



13. Dunn, Emmett Reid. — The Salamanders of the Family Hynobiidae. pp. 443-523. 



June, 1923. SI. 75. 



14. Kellogg, Oliver D. — An Example in Potential Energy, pp. 525-533. In press. 



15. Lewis, Frederic T. — The Typical Shape of Polyhedral Cells in Vegetable Paren- 



chyma and the Restoration of that Shape following Cell Division, pp. 535-554. 

 3 pis. June, 1923. S.S0. 



