THE JOURNAL 
^y.oG (73) ^ 
OF 
EXPERIMENTAL ZOOLOGY 
EDITED BY 
William E. Castle 
Harvard University 
Edwin G. Conklin 
Princeton University 
Charles B. Davenport 
Carnegie Institution 
Horace Jayne 
The Wlstar Institute 
Herbert S. Jennings 
Johns Hopkins University 
Frank R. Lillie 
University of Chicago 
Jacques Loeb 
Rockefeller Institute 
Thomas H. Morgan 
Columbia University 
George H. Parker 
Harvard University 
Charles O. Whitman 
University of Chicago 
Edmund B. Wilson, Columbia University 
and 
Ross G. Harrison, Yale University 
Managing Editor 
VOLUME 9 
1910 
THE WISTAR INSTITUTE OF ANATOMY AND BIOLOGY 
PHILADELPHIA, PA. 
