^5^^^7^ 





SCIENCE 



A WEEKLY JOURNAL 



DEVOTED TO THE ADVANCEMENT OF SCIENCE. 



Editorial Committee : S. Newcomb, Mathematics ; E. S. Woodwaed, Mechanics ; E. C. Pickeeing, 



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



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



C. Haet Meeeiam, Zoology ; S. H. Scuddee, Entomology ; C. E. Bessey, N. L. Beitton, 



Botany ; Heney F. Osboen, General Biology ; C. S. Minot, Embryology, Histology ; 



H. P. Bowditch, Physiology ; J. S. Billings, Hygiene ; J. McKeen Cattell, 



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



NEW SERIES. VOLUME VII. 

 JANUARY -JUNE, 1898. 



NEW YORK 



THE MACMILLAN COMPANY 



1898 



