PROCEEDINGS 



OF THE 1 1 ' 



AMERICAN PHILOaOPoHMAJ^ SOCIETY 



HELD AT PHlikfoELtin'i 

 FOR PROMOTING USEFUL KNOWLEDGE 



Vol. XLIII. April-October, 1904. No. 177. 



CONTENTS. 



PAGB 



The Origin and Nature of Color in Plants. By Henry Kraemer. 257 

 The Historical Use of the Relative Pronouns in English Literature. 



By Prof. Waterman T. Hbwett, Ph.D 278 



Opisthenogenesis, or the Development of Segments, Median Tuber- 

 cles and Markings a iergo. By Alpheus S. Packard, LL.D. 289 

 Orthic Curves ; or, Algebraic Curves which Satisfy LaPlace's Equa- 

 tion in Two Dimensions. By Charles Edward Brooks, 



AB 394 



Palladium (Pd) . By Joseph Wharton 332 



Stated Meeting, April 15 338 



Stated Meeting, May 6 339 



Stated Meeting, May 20 339 



Stated Meeting, October 7. . 340 



^ philadelphia : 

 The American Philosophical Society, 

 104 South Fifth Street. 

 1904. 



