BIOLOGICAL BULLETIN 



OF THE 



flDarine Biological laboratory 



WOODS HOLE, MASS. 



Editorial Staff 



E. G. CONKLIN Princeton University. 



GEORGE T. MOORE The Missouri Botanic Garden. 



T. H. MORGAN Columbia University. 



W. M. WHEELER Harvard University. 



E. B. WILSON Columbia University. 



JEMtor 



FRANK R. LILLIE The University of Chicago 



VOLUME XXXV. 



WOODS HOLE, MASS. 

 JULY TO DECEMBER, 1918 



