the white
of an egg; is slippery to the touch, tasteless, and odorless. Plasmodia
vary in color in different species and at different times in the same
species. The prevailing color is yellow, but may be brown, orange, red,
ruby-red, violet, in fact any tint, even green. Young plasmodia in
certain species are colorless (as in _Diderma floriforme_), while many
have a peculiar ecru-white or creamy tint difficult to define. Not only
does the color change, sometimes more than once in the course of the
life history of the same species, but it may be the same for several
forms, which in fruit are singularly diverse indeed, so that the mere
color of the plasmodium brings small assistance to the systematist. In
fact, the color depends no doubt upon the presence in the plasmodium of
various matters, more or less foreign, unassimilated, possibly some of
them excretory, differing from day to day.

In its plasmodial state, as has been said, the slime-mould affects damp
or moist situations, and during warm weather in such places spreads over
all moist surfaces, creeps through the interstices of the rotting bark,
spreads between the cells, between the growth-layers of the wood, runs
in corded vein-like nets between the wood and bark, and finds in all
these cases nutrition in the products of organic decomposition. Such a
plasmodium may be divided, and so long as suitable surroundings are
maintained, each part will manifest all the properties of the whole.
Parts of the same plasmodium will even coalesce again. If a piece of
plasmodium-bearing wood be brought indoors, be protected from
desiccation by aid of a moist dark chamber, not too warm (70 deg. F.), the
organism seems to suffer little if any injury, but will continue for
days or weeks to manifest all the phenomena of living matter. Thus,
under such circumstances, the plasmodium will constantly change shape
and position, can be induced to spread over a plate of moist glass, and
so be transferred to the stage of a microscope, there to exhibit in the
richest and most interesting and abundant fashion the streaming
protoplasmic currents. As just indicated, the plasmodia follow moisture,
creep from one moist substance to another, especially follow nutritive
substrata. They seem also to secure in some way exclusive possession. I
have never seen them interfered with by hyphae or enemies of any sort,
nor do they seem to interfere with one another. Plasmodia of two common
species, _Hemitric