

JOURNAL OF SCIENCE. 



Editor: EDWARD S. DANA. 



ASSOCIATE EDITORS 



Professors GEORGE L. GOODALE, JOHN TROWBRIDGE, 

 W. G. FARLOW and WM. M. DAVIS, of Cambridge, 



Professors ADDISON E. VERRILL, HORACE L. WELLS, 



LOUIS V. PIRSSON, HERBERT E. GREGORY 



and HOR^' g S. UHLER, of New Haven, 



Pressor HENRY S. WILLIAMS, of Ithaca, 



Professor JOSEPH S AMES, of Baltimore, 



Mr. J. S. DILLER, of Washington. 



FOURTH SERIES 



VOL. XLV— [WHOLE NUMBER, CXCV] 

 No. 265— JANUARY, 1918. 



JfSJY/t 



NEW HAVEN, CONNECTICUT. 



1918. 



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Entered as second-class matter at the Post Office at New Havsn, Conn., under the Act 

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