290 FUNGI. 
are an acquisition, and may be secured in the following manner: 
After the fungus has been soaked in water, where that is neces- 
sary, and the hymenium extracted on the point of a penknife, let 
it be transferred to the centre of a clean glass slide. A drop of 
glycerine is let fall upon this nucleus, then the covering glass 
placed over it. A slight pressure will flatten the object and expel 
all the superfluous glycerine around the edges of the covering 
glass. A spring clip holds the cover in position, whilst a camel- 
hair pencil is used to remove the glycerine which may have been 
expelled. This done, the edges of the cover may be fixed to the 
slide by painting round with gum-dammar dissolved in benzole. 
In from twelve to twenty-four hours the spring clip may be 
removed, and the mount placed in the cabinet. Glycerine is, 
perhaps, the best medium for mounting the majority of these 
objects, and when dammar and benzole are used for fixing, there 
is no difficulty experienced, as is the case with Canada balsam, 
if the superfluous glycerine is not wholly washed away. Speci- 
mens of Puecinia mounted in this way when fresh gathered, 
and before any shrivelling had taken place, are as plump and 
natural in our cabinet as they were when collected six or seven 
years ago. 
Moulds are always troublesome to preserve in a herbarium in 
a state sufficiently perfect for reference after a few years. We 
have found it an excellent method to provide some thin plates of 
mica, the thinner the better, of a uniform size, say two inches 
square, or even less. Between two of these plates of mica 
enclose a fragment of the mould, taking care not to move one 
plate over the other after the mould is placed. Fix the plates 
by a clip, whilst strips of paper are gummed or pasted over the 
edges of the mica plates so as to hold them together. When 
dry, the clip may be removed, and the name written on thé 
paper. These mounts may be put each in a small envelope, and 
fastened down in the herbarium. Whenever an examination is 
required, the object, being already dry-mounted, may at once be 
placed under the microscope. In this manner the mode of 
attachment of the spores can be seen, but if mounted in fluid 
they are at once detached; and if the moulds are only preserved 
