DEPARTMENT OF THE INTERIOR 
UNITED STATES GEOLOGICAL SURVEY 
WASHINGTON, D. c., Dec.l5,l888. 
Mr.Sereno Watson, Harvard Herbarium, Cambridge, Mass. 
My dear Sir: — 
Mr.Th.Holm,late of Copenhagen, who is now help- 
ing me, and is interested in Hydrocotyle and in the Cyperaceae, 
desires greatly to consult for a short time two works which you 
may have. One is ‘ tRichard,HydroGot. in Ann. Sci.Phys.4.4-5, t. 55, 
f.lO»»,as quoted on p.424 of your Bibliographical Index. The 
other is Tuckerman’s ‘‘Enumeratio methodica Caricum^ ' , 1843. We 
are unable to find either of these in this c ity, al though the lat- 
ter was formerly at the Department of Agriculture, but has been 
mislaid. If not wholly in violation of the rules of your 
library, I would consider it a great favor if you could lend me 
these papers for a few days, and I will see that they are promptly 
and safely returned. 
I enclose official franks. 
