(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. 28 pis. In press. 



2. Birkhoff, George D. and Langer, Rldolpb E. — The Boundary Problems Associated 



with a System of Ordinary Linear Differential Equations of the First Order, pp. 49- 

 128. In press. 



3. Vainio, Edward A. — Lichenes in Insula Trinidad a Professore R. Thaxter Collect i. 



pp. 129-147. January. 1923. SI. 60. 



