PROCEEDINGS 



OF THE 



American Philosophical Society 



■ I 1 ' ■ ' ■/ I 1 ' 1 1 I ) 



HELD AT PHILADELPHiailr 



FOR PROMOTING USEFUL KNOWLEDGE 

 Vol. LVII. 1918. No. 5. 



PAGE 



CONTENTS 



The Genus Galerula in North America. By Geo. F. Atkinson . . 357 



Organization, Reproduction and Inheritance in Pediastrum. By R. A. 



Harper 375 



Lighting in its Relation to the Eye. By C. E. Ferree and G. Rand 440 

 Symposium on Food Problems in Relation to the War : 



L Physiological Effects of a Prolonged Reduction in Diet on Twenty- 

 five Men. By Francis G. Benedict 479 



IL Food Conservation from the Standpoint of the Chemistry of Nu- 

 trition. By H. C. ^HERMAN 491 



III. Some Economic Aspects of the American Food Supply. By J. 



Russell Smith 5°^ 



On the Number of Spiral Nebulce. By Heber D. Curtis . . . .513 



PHILADELPHIA 



THE AMERICAN PHILOSOPHICAL SOCIETY 



104 South Fifth Street 



1918 



