
          instance as I should be extremely gratified to have you sug-
 est two or three (or even one), obvious & invariable diagnostics
 of the Sections Avenacea & [Frestucaceae?];  so that a learner
 could at once refer a grass, of either of these sections, to
 its proper place, without mistake.  For this purpose, the more
 brief the character - provided it is obvious & constant, the
 better.  My greatest objection to the existing [Scha..?] of a
 Natural Arrangement of Plants, arises from the vagueness
 of the characters of the orders, or groups.  There are so
 many alternatives - so many exceptions; the range of the
 definition is so great, & the characters so various, - that it
 is calculated to make a [illegible] utterly despair of finding a plant
 with which he is wholly unacquainted.  I wish to seize upon
 the most obvious & invariable characters, to head each
 group with; & leave the exceptions for the detailed de-
 scriptions.  Now, as to the [grasses?], I believe the [Agrostidea?]
 & the [Parriceae?], may be tolerably well defined: but I 
 feel somewhat at a loss for a good character to dis:
 tinguish the Avenacea & the [Festucea?]; - and it is in
 regard to these two sections, especially, that I wish to
 profess your views - if Agardh has not furnished a good
 discrimination.  I hope and trust your engagements
 will not prevent your doing me this favor; as
 I should greatly regret the want of any good arrange:
 ment which is already know to others. My situation,
 here, deprives me of many advantages which ought
 to be [professed?] by any one who undertakes to determine
 & arrange plants: and I might, in part, rely upon
 the kindness of friends to supply the deficiencies
 incident to my position.  Although I propose in my
 Chester County flora, to arrange the plants according to the
 Sexual System; as being better calculated to enlsit students;
 yet I am perfectly aware, such enlisted recruits can
 only be disciplined into good Botanists by the study
 of the Natural Method.  I am, myself, very partial to

        