Oct . 9, 1890. 
169 Mt . Prospect Ave., Nevark, N.P. 
D ear St. Watson : - 
Please accept my best thanks for the copy of your 
contributions^No . I7^which I value very highly. I shall have the 
uleasure of sending you next month a copy of ray paper shovang struc- 
tural differences betv/een the barks of Rha-rnnus Purshiana and R. 
Calif ornioa. I cannot help feeling a.fter a long study of heroariun 
specimens and structural characters of the bark ^ that Rhainnus 
tcraentella of Bentharn is a good species. I cannot anyvrhere find 
specimens x^hich sho’.v much of an intermediate character between this 
form and the R. Calif ornica. 
Very truly yours , 

