VI CONTENTS. 



IX. The Genera of North American Melanopli. By Samuel H. 



S<!UDDER 193 



X. Cycle in the Life of the Individual {Ontogeny') and in the Evolu- 

 tion of its own Group (^Phyhgeny). By Alpheus Hyatt . 2C7 



XI. The Viscosity of Mercury Vapor. By A. A. Noyes and II. M. 



Goodwin 225 



XII. On the Action of Ammonia upon Cupriammonium Acetohromide. 

 By Theodore William Richards and Robert Jay 

 forsythe 237 



XIII. On Obtaining ifeteorological Records in the Upper Air by Means 



of Kites and Balloons. By A. Lawrence Rotch . . . 243 



XIV. The Energy Conditions necessary to produce the Rontgen Rays. 



By John Trowbridge 253 



XV. A Measure of Variability, and the Relation of Individual Varia- 

 tions to Specif c Differences. By Edwin Tenney Brewster 267 



XVI. 1. Revision of the Mexican and Central American Species of 

 Houstonia. 



2. Key to the Mexican Species of Liabum. 



3. Description of Neio or Little known Plants from Mexico. By 



J. M. Greenman 281 



Proceedings 315 



Biographical Notices 331 



Francis James Child 333 



Thomas Tracy Bouve 340 



Francis Amasa Walker 344 



Benjamin Apthorp Gould 355 



List of the Fellows and Foreign Honorary Members . . . 361 



Statutes and Standing Votes 369 



Index 381 



