BIOLOGICAL BULLETIN 



OF THE 



fiDarine Biological Xaborator^ 



WOODS HOLE, MASS. 



Efcitorial Staff 



E. G. CONKLIN Princeton University. 



JACQJJES LOEB The Rockefeller Institute for Medical Research. 



T. H. MORGAN Columbia University. 



W. M. WHEELER Harvard University. 



E. B. WILSON Columbia University. 



FRANK R. LILLIE The University of Chicago. 



VOLUME XXVI. 



WOODS HOLE, MASS. 

 JANUARY TO JUNE 19 



