XJJL-J A J_IU V V^-L/^-A 



QUARTERLY 



HfiSL 



REVI 



OF 



BIOLOGY 



DECEMBER 



1928,^ lAN7s ^% 



Vol. Ill 



'"Nor! 



Published by 



THE WILLIAMS & WILKINS COMPANY 



BALTIMORE 



U. S. A. 



