BIOLOGICAL BULLETIN 



OF THE 



nrmrine Biological laboratory 



WOODS HOLE, MASS. 



^tutorial Staff 



E. G. CONKLIN Princeton University. 



JACQUES LOEB The Rockefeller Institute for ]\Iedical Research. 



GEORGE T. MOORE The Missoziri Botanic Garden. 



T. H. MORGAN Columbia University. 



W. M. WHEELER Har-card University. 



E. B. WILSON Columbia University. 



FRANK R. LILLIE The University of Chicago. 



VOLUME XXXI. 



WOODS HOLE, MASS. 

 JULY TO DECEMBER 1916 



