THEIR HABITATS GENERALLY.
25
this habitat, and they occur chiefly in tropical countries. It
often happens that plasmodium which has fed on dead wood
or leaves may roam away on to soil to fruit, but in some cases
it is clear that it has been feeding in the soil itself.
In Epping Forest, Colloderma oculatum, besides its habitat
on living and dead trees, has repeatedly been found amongst
moss [Campylopus) on peaty soil, not only near old stumps, but
also on open heathy ground This, however, can hardly be
called " bare earth."
On the bare face of a cliff, on the island of Kii, Japan, Mr.
Minakata found a small form of Badhamia affinis. He de-
scribes its occurring " in the terrace-like grooves naturally
formed by sea-waves in a past geologic age, on a rocky
hillock " near the sea ; the insides of these grooves are covered
with mossy and algal growths, which form therein some scanty
soil, upon which these Mycetozoa were seated. He kindly sent
me the specimen, with a sketch in Indian ink of the unpromising-
looking situation in which the inconspicuous sporangia were
obtained.
An interesting example of a true "bare earth " habitat
was observed by Mr. Petch in Ceylon. He describes finding
the plasmodium of Physarum gyrosum developing on the
surface of land which had been prepared for planting Cacao
seedlings by digging holes, one foot cube. On the sides
of two of these holes, the creamy white plasmodium was
noticed emerging in the evening to form small pillars,
one centimetre high, and about six inches below the
surface of the hole ; in the morning all the pillars had
collapsed into small rosettes which formed almost a con-
tinuous sheet on stones, pieces of glass, and earth. Ceylon
soil, he writes, is notoriously deficient in organic matter, but
this soil was rather richer than usual. Mr. Petch also describes
finding Comatricha pulchella frequently ripening on the earthen
galleries of Termites which overrun dead Erythrina logs ; in
this case, however, it was dead wood, probably, that had
afforded provender for the plasmodium..
Mr. C. O. Farquharson, writing from South Nigeria, refers
to several species of Mycetozoa emerging from the soil to form
sporangia, and of his plan of laying traps for them, by placing
dead leaves or sticks lightly on the plasmodium, "as it is