![](./pubData/source/images/pages/page60.jpg)
last branches meeting at the surface of the sporangium by twos
or threes at a very sharp angle, where their slightly thickened
ends are joined together by minute, membranaceous plates.
Sporangium wall not apparent, except a slight collar around
the stipe as it enters the sporangium; spores brown in mass,
very hght-violet, almost colourless, under the microscope, perfectly
smooth, 7— 8 mm. in diameter.
On rotten logs, Philadelphia, Pa.
This plant has been found during three seasons in Fairmont
Park, Philadelphia, Pa., in many localities. The plasmodmm
has a dirty-brown colour. When erecting, the dark, granular
substance of the mass is left in the matter which is to form
the stipe, and the globule of the sporangium becomes milky
white. Before the stipe has reached its full height, say in the
upper fifth, the sporangium mass leaves behind it, clustered
around the stipe, several (2—8) clear, highly-refractive, minute
globules, which, in a recently-matured plant, sparkle like dew-
drops. The plant continues erecting, but from the place where
the globules are left behind, the stipe very frequently suddenly
narrows, sometimes to a mere filament. As the plants become
old, the dew-like globules become amber-coloured, but remain
transparent. These clear globules have been occasionally noted
by the writer on the sporangium wall of Gomatrichas, and have
been considered as an indication of some degree of immaturity,
hence they have not been mentioned in the description as
having a specific value. In the plants, as found in different
places, they are constant, though sometimes fused into one
mass. The finer filaments of the capillitium, in fluid under
the microscrope, are almost colourless. The plants are more
or less sociable, sometimes forming patches an inch or so in
diameter, and may readily be mistaken for a mould. (Wing.)
Orthotricha microcephala, Wingate, in Proo. Acad. Nat. Science,
Philadelphia, 1886, p. 125; Saoc., Syll, vii., pt. I., n.
Airsicc.—-Ellis and Everhart, N. Amer. Fung., Ser. II., n. 2498.
A very beautiful and at the same time puzzling form. I am
not at all convinced in my own mind as to whether the present
genus belongs to the present division or to the Peritrieheae.
CALOTRICHEAE.
The varied types of ornamentation under the form of warts,
spines, or raised bands, often arranged in the form of half-rmgs,
or anastomosing to form a network on the surface of the capillitium
tubes, constitute the most pronounced character of the
present order. In connection with spore dissemination, the
capillitium here reaches its highest development, due to the
elasticity of the tubes, which are never rigid with lime, and
in the most perfect genera are quite free from the sporangial
wall. The elasticity is not due to stretching, hut to the sudden
straightening out of previously coiled-up tubes. If an immature
sporangium of Areyria cinerea having the spores and capillitium
fully differentiated, is hardened in alcohol, a section shows the
tubes of the capillitium, which are combined to form a network,
to he much contorted, and consequently shortened so that the
net-like structure is not evident, the interspaces between the
convolutions of the tubes being filled with spores. This arrangement
of parts continues until the spores are mature, and owing
to the disappearance of water, form a powdery mass, when the
coiled-up tubes straighten out and the network becomes fully
expanded, resulting in an increase of ten or more times in the
length and breadth of the capillitium. This expansion takes
place suddenly, with the result that the mass of spores are
carried up and dispersed. During the expansion of the capillitium
the sporangial wall is torn into fragments, and disappears
with the exception of a small portion at the base which, owing
to its firmer consistency and comparative freedom from the
expansion exerted by the capillitium, remains in the form of
a cup or calyculus. In the genius Trichia the free tubes or
elaters are very much coiled up and contorted until the spores
are mature, when by suddenly straightening out, the wall of
the sporangium is ruptured and some of the spores thrown out,
but the arrangement is not so perfect as in Arcyria. In some
of the comparatively imperfect genera, as Perichaena, the
capillitium is scanty or obsolete. Yellow is the predominating