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From the Journal of the Cincinnati Society of Natural History, Oct.
1892, Jan. 1893.


THE MYXOMYCETES OF THE MIAMI VALLEY, OHIO.

BY A. P. MORGAN.

First Paper.

(Read January 3, 1893.)


Table of Contents

MYXOMYCETES, Wallr.

  Order        Genera               Page
  LICEACEAE.                            4
               Licea                   4
               Tubulina                6
               Lycogala                7
  RETICULARIACEAE.                     10
               Reticularia            10
               Clathroptychium        12
               Cibraria               13
               Dictydium              16
  PERICHAENACEAE.                       19
               Perichaena              19
               Ophiotheca             21
  ARCYRIACEAE.                         23
               Lachnobolus            23
               Arcyria                24
               Heterotrichia          27
  TRICHIACEAE.                         28
               Hemiarcyria            29
               Calonema               33
               Trichia                34
               Oligonema              40
  STEMONITACEAE.                       43
               Clastoderma            44
               Lamproderma            45
               Comatricha             48
               Stemonitis             52
               Enerthenema            56
               Diachaea               56
  DIDYMIACEAE.                         58
               Didymium               59
               Spumaria               64
               Diderma                66
               Lepidoderma            72
  PHYSARACEAE.                         73
               Angioridium            75
               Cienkowskia            75
               Leocarpus              76
               Physarella             78
               Cytidium               80
               Craterium              84
               Physarum               88
               Fuligo                102
               Badhamia              105
               Scyphium              109


  List or Illustrations

  Vol. XV.  Plate III.  Figs. 1-12.
  Vol. XVI. Plate I.    Figs. 13-24.
  Vol. XVI. Plate XI.   Figs. 25-36.
  Vol. XVI. Plate XII.  Figs. 37-48.
  Vol. XIX. Plate XIII. Figs. 49-55.
  Vol. XIX. Plate XIV.  Figs. 56-63.
  Vol. XIX. Plate XV.   Figs. 64-73.


PRESTON, HAMILTON COUNTY, OHIO, December 28, 1892.

MR. DAVIS L. JAMES

_Dear Sir_--Along with this I send you the first installment of the
papers, entitled "The Myxomycetes of the Miami Valley, Ohio."

The work in these papers is based upon my ample collection of
Myxomycetes growing in this region, comprising more than one hundred
species; these have been diligently compared with specimens obtained
from correspondents elsewhere in this country and in Europe.

At the same time, I have also included many extra limital species. This
has been done chiefly to more clearly elucidate the subject in places
where the local material is not sufficient.

The only apology I can make for the arrangement which I present, is that
I have been obliged to choose from several different systems. I have
aimed not to hamper myself, by attaching paramount importance to some
particular character throughout.

I purpose to furnish a synopsis of the whole at the end of the work.

  Very truly yours,
  A. P. MORGAN.

       *       *       *       *       *




MYXOMYCETES, Wallr.


Fructification essentially a minute membranaceous vesicle, the
SPORANGIUM inclosing the SPORES, the product of a motile protoplasmic
body called the PLASMODIUM.

Microscopic organisms with the habit of the Fungi. The ripe spore of the
Myxomycetes is globose or ellipsoidal in shape, with the epispore
colorless or colored, and smooth or marked by characteristic
surface--sculpture according to the species; the spore in germination
gives rise to an elongated protoplasmic body, which exhibits amoeboid
movements, and is known by the name of _swarm-cell_. The swarm-cells
multiply by bipartition, which may be repeated through several
generations; they then unite together to form the large motile
protoplasmic bodies named _plasmodia_. The newly-formed plasmodium is
distinguished by its greater size from the swarm-cells, while it
exhibits essentially the same movements and changes of shape. The
plasmodia gradually increase in size, and as they grow assume commonly
the form of branched strands; these spread over the surface of the
substratum, which is usually the decaying parts of plants, in the form
of veins and net-works of veins, giving rise to a copiously-branched
reticulated or frill-like expansion, which covers surfaces varying in
extent from a few to several centimeters. They are chiefly composed of a
soft protoplasm of the consistence of cream, which may be readily spread
out into a shapeless smear, and is usually colorless, but sometimes
exhibits brilliant colors of yellow, orange, rose, purple, etc. The
development of the plasmodium ceases with the formation of the _spores_
within their _sporangia_.

The formation of the sporangia out of the plasmodium appears under three
general forms, which, however, pass into each other and are, therefore,
not strictly limited.

_First:_ An entire plasmodium spread out on its substratum becomes
transformed into a sporangium, or it divides into a variable number of
unequal and irregular pieces, each of which undergoes transformation.
Such a sporangium lying flat on the substratum, more or less elongated
and flexuous, often branched and reticulate, is termed a
_plasmodiocarp_.

_Second:_ Erect sporangia on a narrow or stalk-like base, begin as
node-like swellings on the branches of the plasmodium, and gradually
rise to their ultimate form as the surrounding protoplasm flows into
them and assumes an upward direction. These sporangia are nearly always
perfectly regular in shape; they may be globose, obovoid, somewhat
depressed, or more or less elongated, and are either stipitate or
sessile.

_Third:_ A number of plasmodia collect together from every side and
become fused into a single body, often of considerable dimensions; from
these combinations originate the large spore-receptacles which are
called _aethalia_. The component sporangia may be regular in shape,
standing close together, in a single stratum, with entire connate walls;
more often, being elongated and flexuous, they branch and anastomose
freely, their walls becoming perforated and more or less defective; in
other cases, the aethalium is a compound plasmodiocarp, the narrow
sinuous sporangia branched and anastomosing in all directions, forming
an intricate network, closely packed together and inseparable. The
surface of the aethalium is often covered by a continuous layer of some
excreted substance, which is called the _common cortex_.

The wall of the sporangium, typically, is a thin, firm membrane,
colorless and pellucid, or colored in various shades of violet, brown,
yellow, etc.; it is sometimes extremely delicate, as in Lamproderma, or
is scarcely evident, as in Stemonitis; in other instances it is
thickened by deposits on the inner surface, as in Tubulina, or by
incrustations on the outer surface, as in Chondrioderma. The stipes are
tubes usually with a thick wall, which is often wrinkled and folded
lengthwise, and is confluent above with the wall of the sporangium; in
some cases the stipe also enters the sporangium, and is more or less
prolonged within it as a _columella_. The stipe commonly expands at the
base into a membrane, which fastens it to the substratum, and is called
the _hypothallus_; when all the stipes of the same group of sporangia
stand upon a single continuous membrane, it is called a _common
hypothallus_.

In the simplest forms, the cavity of the sporangium is filled
exclusively with the numerous spores; but in most all of the genera,
tubules or threads of different forms occur among the spores and
constitute the _capillitium_. The capillitium first makes its appearance
in Reticularia, in which upon the inner surface of the walls of the
sporangia there are abundant fibrous thickenings; next in Cribraria it
is spread over the inner surface of the wall, and is early separated
from it; here, also, it first assumes a more definite form and
arrangement; in Physarum it is in connection with the wall of the
sporangium only by its extremities while it traverses the interior with
a complicated network; in Stemonitis and its allies the capillitium
originates wholly from the columella; in most species of Arcyria it
issues from the interior of the stipe. The capillitium in Trichia
consists of numerous slender threads which are _free_, that is, are not
attached in any way; they are usually simple and pointed at each
extremity; the surface of these threads exhibits beautiful spiral
markings.




ORDER I. LICEACEAE.


Sporangia always sessile, simple and regular or plasmodiocarp, sometimes
united into an aethalium. The wall a thin, firm, persistent membrane,
often granulose-thickened, usually rupturing irregularly. Spores
globose, usually some shade of umber or olivaceous, rarely violaceous.

The species of this order are the simplest of the Myxomycetes; the
sporangium, with a firm, persistent wall contains only the spores. There
is no trace of a capillitium, unless a few occasional threads in the
wall of Tubulina prefigure such a structure. To the genera of this order
is appended the anomalous genus Lycogala, which seems to me better
placed here than elsewhere.

TABLE OF GENERA OF LICEACEAE.

1. LICEA. Sporangia simple and regular or plasmodiocarp, gregarious;
hypothallus none.

2. TUBULINA. Sporangia cylindric, or by mutual pressure becoming
prismatic, distinct or more or less connate and aethalioid, seated upon a
common hypothallus.

3. LYCOGALA. AEthalium with a firm membranaceous wall; from the inner
surface of the wall proceed numerous slender tubules, which are
intermingled with the spores.


I. LICEA, Schrad. Sporangia sessile, simple and regular or
plasmodiocarp, gregarious, close or scattered; hypothallus none; the
wall a thin, firm membrane, sometimes thickened with scales or granules,
breaking up irregularly and falling away or dehiscent in a regular
manner. Spores globose, variously colored.

The sporangia are not seated on a common hypothallus; they are,
consequently, more or less irregularly scattered about on the
substratum.

1. LICEA VARIABILIS, Schrad. Plasmodiocarp not much elongated, usually
scattered, sometimes closer and confluent, somewhat depressed, the
surface uneven or a little roughened and not shining, reddish-brown or
blackish in color; the wall a thin, firm pellucid membrane, covered by a
dense outer layer of thick brown or blackish scales, rupturing
irregularly. Spores in mass pale ochraceous, globose or oval, even or
nearly so, 13-16 mic. in diameter.

Growing on old wood. Plasmodiocarp 1-1.5 mm. in length, though sometimes
confluent and longer. The wall is thick and rough, not at all shining.
It is evidently the species of Schweinitz referred to by Fries under
this name.

2. LICEA LINDHEIMERI, Berk. Sporangia sessile, regular, globose,
gregarious, scattered or sometimes crowded, dark bay in color, smooth
and shining; the wall a thin membrane with a yellow-brown outer layer,
opaque, rupturing irregularly. Spores in mass bright bay, globose,
minutely warted, opaque, 5-6 mic. in diameter.

Growing on herbaceous stems sent from Texas. Sporangia about.4 mm. in
diameter. The bright bay mass of spores within will serve to distinguish
the species. The thin brown wall appears dark bay with the inclosed
spores.

3. LICEA BIFORIS, Morgan, n. sp. Sporangia regular, compressed, sessile
on a narrow base, gregarious; the wall thin, firm, smooth, yellow-brown
in color and nearly opaque, with minute scattered granules on the inner
surface, at maturity opening along the upper edge into two equal parts,
which remain persistent by the base. Spores yellow-brown in mass,
globose or oval, even, 9-12 mic. in diameter. See Plate III, Fig. 1.

Growing on the inside bark of Liriodendron. Sporangia.25-.40 mm. in
length, shaped exactly like a bivalve shell and opening in a similar
manner. I have also received specimens of this curious species from
Prof. J. Dearness, London, Canada.

4. LICEA PUSILLA, Schrad. Sporangia regular, sessile, hemispheric, the
base depressed, gregarious, chestnut-brown, shining; the wall thin,
smooth, dark-colored and nearly opaque, dehiscent at the apex into
regular segments. Spores in the mass blackish-brown, globose, even,
16-18 mic. in diameter.

Growing on old wood, Sporangium about 1 mm. in diameter. On account of
the color of the spores the genus _Protoderma_ was created for this
species by Rostafinski. It is number 2,316 of Schweinitz's N. A. Fungi.


II. TUBULINA, Pers. Sporangia cylindric, or by mutual pressure becoming
prismatic, distinct or more or less connate and aethalioid, the apex
convex, seated upon a common hypothallus; the wall a thin membrane,
minutely granulose, firm and quite persistent, gradually breaking away
from the apex downward. Spores abundant, globose, umber or olivaceous.

The sporangia usually stand erect in a single stratum, with their walls
separate or grown together: in the more compact aethalioid forms,
however, the sporangia, becoming elongated and flexuous, pass upward and
outward in various directions, branching and anastomosing freely. See
Plate III, Figs. 2, 3, 4.

1. TUBULINA CYLINDRICA, Bull. Sporangia cylindric, more or less
elongated, closely crowded, distinct or connate, pale umber to
rusty-brown in color, seated on a well developed hypothallus; the wall
thin, firm, with minute veins and granules, semi-opaque, pale umber,
often iridescent. Spores in mass pale umber to rusty-brown, globose,
most of the surface reticulate, 6-8 mic. in diameter.

Growing on old wood, mosses, etc. AEthalium circular or irregular in
shape, from one to several centimeters in extent, the individual
sporangia 2-4 mm. in height. Plasmodium at first milky-white, soon
changing to bright red, then to umber, becoming paler when mature and
dry.

2. TUBULINA CASPARYI, Rost. Sporangia more or less elongated, closely
crowded and prismatic, connate, pale umber to brown in color, seated on
a conspicuous hypothallus; the wall thin, firm, minutely granulose,
semi-opaque, pale umber, iridescent when well matured; all or many of
the sporangia traversed by a central columella, from which a few narrow
bands of the membrane stretch to the adjacent walls. Spores in the mass
pale umber to brown, globose, the surface reticulate, 7-9 mic. in
diameter.

Growing on old prostrate trunks. AEthalium two or three to several
centimeters in extent, the individual sporangia 3-5 mm. in height.
Plasmodium white, the immature sporangia dull-gray tinged with sienna
color. The columella, with its radiating bits of membrane, is the same
substance as the wall; it may be a reentrant edge of the prismatic
sporangium, caused by excessive crowding together; at least, this may be
regarded as its origin; there may have arisen some further adaptation.
The species is _Siphoptychium Casparyi_, Rost. I am indebted to Dr.
George A. Rex for the specimens I have examined.

3. TUBULINA CAESPITOSA, Peck. Sporangia short-cylindric, closely crowded,
distinct or connate, argillaceous olive to olive-brown in color, seated
on a well-developed hypothallus; the wall a thin membrane, with a dense
layer of minute dark-colored round granules on the inner surface. Spores
argillaceous olive in the mass, globose, minutely warted, 6-8 mic. in