
          so frequently in Bridels Bryo. Univ. that your
[herbarium?] must be very authentic for many of our
difficult species, first published in that work, and
which in truth can only be satisfactorily ascertained
by comparison with the original specimens. If it
is worth while I will send you a list - "a small list,  you
know, is of great use to a botanist" (Banks to Linnaeus fil.) - and
this is particularly the case with mosses.

I am sorry to see the slow progress of the 
Flora. I fear that the separation of you & Dr. Gray will
be a hinderance. I would be a sad [illegible]
for our botany if this work should be stopped.
Let us hope better things. I have never been
able to hear a word about the botanical part of
your state survey. But I see by the papers
it is being published. So with patience we
will see after a while. Do not suppose (now that 
Dr. Gray is not at hand to relieve you) that I intend to
become [added: again] a troublesome correspondent & to tax your valuable
time. I shall only write when I have something that
may interest you. In the mean time in any thing I can
do, command me freely. & believe me yours
truly & cordially

W.S. Sullivant

As Mr. Derby informs me you were not to be
found at your usual residence I have directed this to care of Wiley & Putnam
        