6'^^773 



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SCIENCE 



A WEEKLY JOURNAL 



DEVOTED TO THE ADVANCEMENT OF SCIENCE. 



Editoeial Committkk : S. Newcojib, Mathematics ; E. S. Woodwaed, Mechanics ; E. C. Pickeeing, 



Astronomy; T. C. Mendenhall, Physics; E. H. Thueston, Engineering; Iea Eemsen, Chemistry; 



J. Le Conte, Geology; "W. M. Davis, Physiography; O. C. Maesh, Paleontology; "W. K. 



Beooks, C. Haei Meeeiam, Zoology; S. H. SctnoDEE, Entomology; N. L. Beitton, 



Botany; Heney F. Osboen, General Biology; H. P. Bowditch, Physiology; 



J. S. Billings, Hygiene ; J. McKeen Catiell, Psychology ; 



Daniel G. Beinton, J. W. Powell, Anthropology. 



NEW SERIES. VOLUME V. 

 JANUARY -JUNE, 1897. 



NEW YOEK 



THE MACMILLAN COMPANY 



1897 



