BIOLOGICAL BULLETIN 



OF THE 



fiDarine Biological Xaboraton? 



WOODS HOLE, MASS. 



EMtorial Staff 



E. G. CONKLIN Princeton University. 



GEORGE T. MOORE The Missoiiri Botanic Garden. 



T. H. MORGAN Columbia University. 



W. M. WHEELER Harvard University. 



E. B. WILSON Columbia University. 



/IDanacjincj 



FRANK R. LILLIE The University of Chicago. 



VOLUME XXXVIII. 



WOODS HOLE, MASS. 

 JANUARY TO JUNE, 1920 



