v l'^ 



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SCIENCE -^' 



A WEEKLY JOURNAL 



DEVOTED TO THE ADVANCEMENT OE SCIENCE. 



Editorial Committee : S. Newcomb, Mathematics ; E. S. Woodward, Mechanics ; E. C. Pickering, 



Astronomy ; T. C. Mendenhall, Physics ; E. H. Thurston, Engineering ; Ira Eemsen, Chemistry ; 



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



C. Hart Mekriam, Zoology ; S. H. Scudder, Entomology ; C. E. Bessey, N. L. Eritton, 



Botany ; Henry F. Osborn, General Biology ; C. S. Minot, Embryology, Histology ; 



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



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



NEW SERIES. VOLUME VIII. 

 JULY -DECEMBER, 1898. 



NEW YOEK 



THE MACMILLAN COMPANY 



1898 



