BIOLOGICAL BULLETIN 



OF THE 



fiDarinc Biological laboratory 



WOODS HOLE, MASS. 



EMtorial Staff 



E. G. CONKLIN Princeton University. 



JACQUES LOEB The Rockefeller Institute for Medical Research 



T. H. MORGAN Columbia University. 



W. M. WHEELER Harvard University. 



E. B. WILSON Columbia University. 



Managing BMtot 



FRANK R. LILLIE The University of Chicago. 



VoLl ME XXIV. 



\Vou!)S IIOl.K, MASS. 

 DECEMBER 1912, TO MAY 1913 



