BIOLOGICAL BULLETIN 



OF THE 



flDarine Biological laboratory 



WOODS HOLE, MASS. 



JE&ttorial 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. 



BMtor 



FRANK R. LILLIE The University of Chicago. 



VOLUME XLII. 



WOODS HOLE, MASS. 

 JANUARY TO JUNE, 1922 



