^ 



a^ 



BIOLOGICAL BULLETIN 



fiDatine Biologtcal Xaboratori? 



WOODS HOLE, MASS. 





Bbitorial Staff 



E. G. CoNKLiN — Princeton University. 



Jacques Loeb — The Rockefeller Institute for Medical Research 



George T. Moore — The Missotiri Botanical Garde?i. 



T. H. Morgan — Columbia University. 



W. M. Wheeler — Harvard University. 



E. B. Wilson — Cohimbia University. 



^anagiuQ BMtor 



Frank R. Lillie — The University of Chicago. 



Volume XXVIIL 



WOODS HOLE, MASS. 

 JANUARY TO JUNE 1915 



