Sporangium pervious to the base, the interior walls forming a persistent spurious columella; capillitium composed of filaments with here and there minute knot-like thickenings, straight tubes containing lime-granules extending from the exterior to the interior walls of the sporangium, persistently attached to the former.[31]

Such is Dr. Peck's original description of this most peculiar genus. The form of the sporangium in the only species is very variable, but in typical cases is vasiform, the peridial wall at the apex introverted. The capillitium is like that of Tilmadoche, except for the presence of the "straight tubes" emphasized in the original description. These are very remarkable and at once diagnostic. They take origin in the sporangial wall and pass across to the "columella"; but at the dehiscence of the sporangium, in typical cases, they remain attached at the points of origin, projecting as stout spine-like processes.

Physarella oblonga (Berk. & C.) Morg.

[Plate VIII]., Figs. 4, 4 a, 4 b, 4 c; [Plate XVI]., Figs. 1, 1 a, 1 b, and 6.

Sporangia scattered or gregarious, typically cup-shaped or sub-infundibuliform, stipitate, erect or cernuous, but varying through low salver-shaped cups, to irregular applanate and sessile masses, the peridium thin but firm, tawny, roughened by numerous yellowish calcareous scales, at length ruptured above and often reflexed in the form of petal-like segments from which project upwards the spiniform trabecules of the capillitium; stipe when present long, terete, red, arising from a scant hypothallus and extended within the sporangium to meet the tubular "columella"; capillitium of delicate violaceous threads seldom branched or united, radiating from the columella with few calcareous nodular expansions, but supported by stout yellow calcareous trabecules, running parallel to the capillitial threads, long adherent to the sporangial wall; spores smooth, globose violet-brown, 7–8 µ.

Not uncommon in wet places. New York, Ohio, Iowa, South Dakota, Louisiana, Nicaragua; reported also from Ceylon, Java, etc.

Not the least remarkable feature of this remarkable species is the variation in the form of the fruit or sporangia. We have specimens from Louisiana (Rev. Langlois) which show no trace of columella, the whole structure involute and plicate, short stipitate, recalling the extremest complexity of such a species as P. polycephalum. Vid. Pl. XVI., Fig. 6. Moreover, in these specimens the calcareous deposits are white and not yellow, giving the entire fructification a grayish aspect. Yet there is no doubt we have here simply an exaggerated abnormality of the species; the spores are identical in size, color, and surface. Plasmodium bright yellow. Dr. Peck gave to his forms the name Physarella mirabilis; but specimens sent by Michener of Pennsylvania, and by Berkeley and Curtis described as Trichamphora oblonga (Grev., II., p. 66), are the same thing. N. A. F., 1212.

Physarella lusitanica Torrend is a globose form depressed above or betimes discoidal, occurring on Eucalyptus trees in Portugal. P. oblonga is so variable in form that it sometimes suggests a different genus. Forms of it have been mistaken for Fuligo gyrosa R., etc. Professor Torrend would include here Physarum javanicum (Rac.), i. e. Tilmadoche javanica as Raciborski saw it! We may not too often reflect that genera are purely artificial things set up for our convenience; but surely Physarella as a natural genus is distinct enough to all.