HARVARD UNIVERSITY 
Economic Entomology 
W. M. Wheeler 
C. T. Brues 
Genetics 
W. E. CASTLE 
E. M. East 
Comparative Pathology 
Theobald Smith 
BUSSEY INSTITUTION 
FOREST HILLS, MASS., 
Apr.25, 
19 
10 ; 
Prof.J,F.Collins, 
Providence,R.I. 
Dear Prof.Collins: 
The slides are received in good order and I am 
very grateful to you for the trouble you have taken and I am 
sure that they will be of great use to me. I am sending your 
bill to the authorities for payment. 
Very truly yours, 
