BIOLOGICAL BULLETIN 



OF THE 



fiDarinc S3iolooical ^laboratory 



WOODS HOLE, MASS. 











-..** 





EMtorial 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. 



lEMtor 



FRANK R. LILLIE The University of Chicago. 



VOLUME L. 



WOODS HOLE, MASS. 



JANUARY TO JUNE, 1926 



