SCIENCE 



A WEEKLY JOUBNAL 



DEVOTED TO THE ADVANCEMENT OF SCIENCE. 



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



Astronomy; T. C. Mendenhall, Physics; K. H. Thueston, Engineering; Iea Remsen, Chemistry; 



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



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



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



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



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



l^EW SERIES. VOLUME IV. ^ 



JULY -DECEMBER, 1896. 



NEW YOEK. 



THE MACMILLAN COMPANY. 



1896 



