SCIENCE 



A WEEKLY JOURNAL DEVOTED TO THE ADVANCEMENT OF SCIENCE, PUBLISH- 

 ING THE OFFICIAL NOTICES AND PROCEEDINGS OF THE AMERICAN 

 ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE. 



Editorial Committee : S. Newcomb, Mathematics ; E. S. Woodwaed, Mecbanios ; E. C. Pickering, 

 Astronomy ; T. C Mbndenhall, Physics ; R. H. THURSTOlsr, Eugineering ; Ira Remsen, Chemistry ; 

 Charles D. Walcott, Geology ; W. M. Davis, Physiography ; Henry F. Osboen", Paleon- 

 tology; W. K. Brooks, C. Hart Meeeiam, Zoology; S. H. Scudder, Entomology; C. E. 

 Bbssey, N. L. Beitton, Botany ; C. S. Minot, Embryology, Histology ; H. P. Bow- 

 ditch, Physiology ; J. S. BiLLiNGS, Hygiene ; William H. Welch, 

 Pathology ; J. McKeen Cattell, Psychology. 



NEW SERIES. VOLUME 



JULY -DECEMBER^ 1902 



NEW YORK 



THE MACMILLAN COMPANY 



1902 





