sses on to spores.

In the present state of our knowledge the forms of this genus present
withal a most perplexing problem. Are they simply phases of a single
species, or are they in style and in structure sufficiently constant in
their admitted variety, to claim specific rank and separate description?

To follow the example of Greville and recognize in all the literature of
two hundred years varied descriptions of a single type,--this were
perhaps the easier and speedier disposal of the case. Fries thought so
to treat the problem but was unable to keep faith with his own decision;
for no sooner he states the genus monotypic than he proceeds forthwith
to offer four varieties, a. b. c. d., viz. those by Persoon and others
duly recognized as species.

Recent students all, however, seem to find convenience in specific
division. All seem disposed to honor Dr. Peck's _Fuligo ochracea_
whether or not by the name he gave; and of other varieties some seem
impressed by the constancy of one, some of another characteristic, thus
indicating that to careful observers all over the world there are
differences that may be recognized, that have been recognized again and
again. If there are two species there are certainly more. Out of the
gatherings of many years one may set in order not less than five
variations in the fruiting of _Fuligo_, five distinct types of
fructification, to all appearing sufficiently constant for specific
recognition.

It will be said, has been said, was said by Fries, that these variations
are insignificant, "pendent ex aeris constitutione"; but as a matter of
fact the several types now in question may be found on the same day, so
that evidently something other than the atmospheric environment must
determine.

Again it is said that the differences are in external form or color
only, the spores in all cases almost if not quite the same. This is
true; but specific characters are _surface_ characters in fact: a
species morphologically is merely the form in which a _kind_ or _genus_
presents itself. If the presentation be constant, for our convenience we
say so, in bestowing a name. Whether in our present treatment the
convenience is purely personal, students may decide.

However it all may be, there are in this part of the world many varying
presentations of _Fuligo_ capable of illustration and description; the
same forms, perhaps, which have attracted the notice of the more acute
mycologists in the older h