THIS BOOK IS DUE ON THE LAST DATE 

 STAMPED BELOW 



AN INITIAL PINE OF 25 CENTS 



WILL BE ASSESSED FOR FAILURE TO RETURN 

 THIS BOOK ON THE DATE DUE. THE PENALTY 

 WILL INCREASE TO 5O CENTS ON THE FOURTH 

 DAY AND TO $1.OO ON THE SEVENTH DAY 

 OVERDUE. 



BIOLOGY LIBRARY 



PER 16 i<m 



NQV 1 2 194Q 



OEC 4 1961 



DEC 20 1961 



