4 
OHIO BIOLOGICAL SURVEY 
Slime Molds feed upon organic matter. In some cases they use 
organic matter that is in solution while in other cases they ingest solid 
particles as small bits of wood, bacteria, etc. These are digested much 
as similar materials are by an amoeba. They are always destitute of 
chilorophyll and hence cannot produce food by photosynthesis. 
If a plasmodium slowly dries out it may pass into a dormant condition 
called a sclerotium. It may remain in this condition for months when on 
being placed under favorable conditions again it will renew its activities. 
When a plasmodium approaches maturity it generally leaves the moist 
hidden recesses where it has developed and comes out upon the surface of 
a log or may even creep up the stem of a plant for a distance of several 
inches, where the sporangia are formed. A typical sporangium may be 
illustrated by Plate X, fig. 5. In this we see the globular sporangium 
enclosed by the sporangium wall or peridium. The peridium may be 
single or double. Sporangia may be sessile or elevated upon a stalk; they 
may be separate or many gathered together into a compound mass called 
an aethalium as in Fuligo. Within the sporangium wall are found the 
spores and usually a capillitium, consisting of threads which may be simple 
or branched, free or attached to the sporangium wall. These threads are 
often beautifully sculptured and are largely used in the classification of the 
genera. The capillitium, sporangium wall, and stalk are wholly destitute 
of cellular structure, the substance of these being secreted by the 
plasmodium just prior to spore formation. In some genera, also, lime is 
secreted. This may be deposited within the capillitium as in Physarum, 
or in the stalk as in Diachaea, or upon the surface of the sporangium as in 
Diderma. 
In size the forms differ from an aethalium as large as a man’s hand 
to sporangia so small that they are not likely to be detected unless one 
chances to find them while examining sticks, bark, or other objects with 
a hand lens. Specimens may be found on the surface of fallen logs, 
under bark, on decaying leaves or straw, on stems of herbaceous plants 
either dead or living, or even on the ground. Sporangia, as a rule, are 
produced during the summer season but may in certain forms be produced 
in late fall or early winter. The sporangia of the most of the forms are 
evanescent but some forms that fruit under the bark of logs may be 
collected at any time of the year, while forms as Lycogala with a tough 
sporangium wall may endure weathering for several months even when 
fully exposed as when found upon a stump or log. Some species of Slime 
Molds exhibit considerable variation in size, shape, color, or sculpturing. 
At times spores of twice the normal diameter are found among those of 
normal size. Sometimes the capillitium varies much from the normal in 
its abundance, branching, or sculpturing, Stalked, sessile, or plasmodio- 
carpous forms of the same species may sometimes be found in the same 
