BIOLOGICAL BULLETIN 



flDartne Biological Xal)orator)^ 



WOODS HOLE, MASS. 



Editorial Staff 



E. G. CoNKLiN — The University of Pennsylvania. 

 Jacques Loeb — The University of California. 

 T. H. Morgan — Columbia Unive?'siiy. 

 W. M. Wheeler — American Museum of Natural 



History, New York. 

 C. .0. Whitman — The University of Chicago. 

 E. B. Wilson — Columbia University. 



/IDanaging BMtor 



Frank R. Lillie — The University of Chicago. 



Volume XVIII. 



WOODS HOLE, MASS. 

 DECEMBER 1909 TO MAY 1910. 



•^13 0^4 



