
          Fort Gratiot Michigan
 30 July 1849

 My dear sir,

 I have recently noticed in Dr. Gray's "Manual
 of the Botany of the Northern United States", that he says
 p.219 under the head Silphium laciniatum" lower leaves
 said to present their faces uniformly north and south (which
 is not the case) and hence called compass plant."

 He should have said that it is alleged that
 the edges are presented uniformly north & south.  In your
 communication to me of 14 March 1843 acknowledging the
 reception of a letter & specimen of the plant from me
 you alluded to the joint labors of Dr. Gray & yourself
 in publishing a work on the "Flora of North America".
 I infer then from that this denial of the polarity of the 
 plant by Dr. Gray proceeds from your want of faith
 in my allegations as set forth in my letters to you &
 in my published letters to the National Institute of Aug. [August]
 1842 and January 1843. It is true that this manual is 
 published in the name of Dr. Gray, & I perceive that
 the portion of your "Flora of N.A. [North America]" referring to the 
 Silphium laciniatum was published in April 1842
 before my letters were published. Still as in your
 letter to me you asked me to communicate on 
 such subjects: and said that "any name or new plants 
 or observations on species already known that you
 may send as shall be faithfully recorded & proper
 acknowledgements made".  I infer that this want
 of evidence in this subject may have originated with you.
 If so, your sources of information are mistaken in the premises.

 [Written in left column at 90 degrees: Look at Short's [Charles Wilkins Short] paper on the botany of the Prairies of Illinois. I have an [?]
 that he there contradicts the statement as to the polarity of the leaves. [?]]
        