108 THE NORTHERN MICROSCOPIST. 
that condition, we have sometimes sprinkled them with water from 
an adjoining stream ; and in a minute or two, they have yielded 
beautifully to the broadish point of the knife beneath them. 
Specimens should always be gathered, if possible, in fruit ; and as 
near complete as can be. Preparations should be made for this 
out-door work. Put on clothes which will neither trouble nor deter 
you from thrusting yourself into anycorner. Let your boots be such 
as will cross swampy ground, or dip into a stream without discom- 
fort. You will also require a pocket lens ; a strong, sharp knife; a 
hammer, and two or three mason’s chisels. If you carry only one 
chisel, and have to face hard rocks, during the first fifteen minutes 
you may find yourself half helpless for the rest of the day, by the 
turning or breaking of your chisel point. Crustaceous Lichens 
are gathered by cutting away a piece of the stone on which they 
grow, and the other forms accordingly. You will further need a 
botanical box, or small basket, and many of the specimens will 
require wrapping in paper, to prevent rubbing, in carrying them 
home. ‘Take particular note where the plants are gathered, so 
that the locality in a word or two can be written upon the sheets 
when they are mounted. 
On reaching home with your gatherings, the first thing to be done 
is to press and dry the foliaceous and fruticulose forms. Then 
mount the whole on slips of paper, with gum or glue. We find 
nothing to answer this purpose better than a thick solution of 
gum Arabic, with a few drops of glycerine in it, to modify its 
brittleness. On each slip of paper record the place where gathered, 
with date, and collector’s name. The plants may now be placed 
together on one side, without danger of confusion, and be brought 
out one by one for determination or study as you may have leisure 
and opportunity. In the investigation of Lichen tissues and 
sporidia, and the determination of species, there will be required a 
compound microscope, with a magnifying power of from 60 to 400 
linear measurement (one-inch and quarter-inch objectives with A 
and C eye-pieces) ; also, a double lens for the eye. Some use an 
ordinary watchmaker’s eye-glass. One of these glasses mounted 
in a pair of spectacle frames, would be very useful for the licheno- 
logist. A small thin dissecting knife, and solutions of iodine, 
hydrate of potash, and hypochlorite of lime. The making up, 
with the application of these re-agents, are fully described in 
Leighton’s Lichen-Flora. ‘The iodine acts more or less upon the 
gelatina-hymenea of the paraphyses and asci, turning them blue, 
yellow, or vinous-red. ‘The hydrate of potash dissolves the gela- 
tina-hymenea, and shows the hymenium more clearly under the ~ 
microscope, beside swelling the spores and paraphyses up to their 
full size. The hydrate of potash and hypochlorite of lime are also 
used on the Lichen-thallus as tests ; and, as such, are of consider- 
