JOURNAL 
OF 
MORPHOLOGY 
FouNDED BY C. O. WHITMAN 
EDITED BY 
J. SK INGSLE Y 
Tufts College, Mass. 
WITH THE COLLABORATION OF 
Gary N. CALKINS T. H. MonTGoMERY 
Columbia University University of Pennsylvania 
W. M. WHEELER WILLIAM PATTEN 
Bussey Institution, Harvard University Dartmouth College 
Epwin G. CoNKLIN 
Princeton University 
VOLUME 22 
Pe 
THE WISTAR INSTITUTE OF ANATOMY AND BIOLOGY 
PHILADELPHIA 
