JUL 15 1905 



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. 



NEW SERIES. VOLUME XXI. 



JANUARY-JUNE, 1905. 



^ NEW YORK 

 THE MACMILLAN COMPANY 

 1905 



