26 PRACTICAL HINTS ON THE STUDY OF THE MYCETOZOA.
creeps through the lower layer to the dryer parts to form into
sporangia, but seldom reaches the lately fallen superficial leaves.
In permanently storing the specimens, after cutting off the
superfluous part of the leaf or dead wood, glue the object on to a
card tray with the two ends turned up at right angles, so that it
will loosely fit into a match box, or better still, a paste-board box
with a free lid. Such boxes are sold by Messrs. Maw, Aldersgate
Street, London, for about 1s. 6d. a gross. The turned up ends
of the tray protect the specimen when taken out of the box if
it should happen to fall.
In preparing a sporangium for examination on a glass slide,
first supply a drop of strong methylated spirit to expel the air
from among the spores ; then add water and carefully wash out the
spores from among the capillitium with the aid of a couple of
mounted needles. As this requires some delicacy of treatment,
it should be done under a watchmaker's glass mounted on some
simple stand. Then lay on a thin cover glass, and the object
is ready for the microscope.
If the specimen is to be preserved, mount in Glycerine-jelly.
My own practice is, after draining off the water and superfluous
spores, to add a drop of I to 20 solution of Carbolic Acid. Let
this also be drained off, and with a knitting needle, place on the
object a drop of Glycerine-jelly, melted by immersing the bottle
containing it, in hot (not boiling) water. Lay the glass slide on a
flat bottle filled with hot water, you can then at your leisure
arrange the sporangia and capillitium before putting on the thin
cover. This should be done under the watchmaker's glass, and
care must be taken to avoid including bubbles of air. These air
bubbles under the cover glass give trouble at first, but you soon
learn to avoid them with the hot plate. When the preparation
is cold, carefully wash off the jelly round the edges of the thin
cover glass and wipe dry ; then ring with Hollis's Glue, and after
a few hours paint over the glue with Gold Size. Specimens
prepared in this manner will last in perfect condition for very
many years. Canada Balsam in Xylol is a much simpler medium
to use and is the best for mounting sporangia of the genus
Cribraria ; but in species in which the markings on the spores are
an important character, glycerine-jelly is essential, as in balsam
the spores shrink.
I would strongly advise any one who takes up the study of
the Mycetozoa to record in a note book the date and circumstances
of each gathering, with a drawing, if only in outline, of the