Proceeding's of the American Academy of Arts and Sciences. 

 Vol. XXXII. No. 15. — May, 1897. 



CONTRIBUTIONS FROM THE ZOOLOGICAL LABORATORY OF 

 THE MUSEUM OF COMPARATIVE ZOOLOGY AT HARVARD 

 COLLEGE, E. L. MARK, DIRECTOR, No. LXXIX. 



A MEASURE OF VARIABILITY, AND THE RELATION 



OF INDIVIDUAL VARIATIONS TO SPECIFIC 



DIFFERENCES. 



By Edwin Tenney Brewster. 



