BIOLOGICAL BULLETIN 



OF THE 



flDarine Biological laboratory 



WOODS HOLE, MASS. 



LIBRAR 



Efcitorial Staff 



GARY N. CALKINS Columbia University. 



E. G. CONKLIN Princeton University. 



M. H. JACOBS University of Pennsylvania. 



FRANK R. LILLIE University of Chicago. 



GEORGE T. MOORE The Missouri Botanic Garden. 



T. H. MORGAN Columbia University. 



W. M. WHEELER Harvard University. 



E. B. WILSON Columbia University. 



flDanaomo JE&ttor 



C. R. MOORE The University of Chicago. 



VOLUME LI I. 



WOODS HOLE. MASS. 



JANUARY TO JUNE, 1927 



