169 
but this can be removed at any time by means of hydrogen pet- 
oxide. I have frequently prepared museum specimens of fleshy 
or even gelatinous fungi by these means, so that they remain per- 
manently as firm as india-rubber and without contraction, and 
although they gradually deteriorate for histological purposes 
afterwards—e.g., as regards staining properties, &c., if kept long 
in alcohol, and especially if kept in absolute alcohol—even this can 
be got over to some extent by keeping them in a mixture of 
alcohol, glycerine, and water. 
These are by no means the only methods which have been 
devised for hardening, fixing and preserving fungi, but I have 
selected them as two of the best known to me for general pur- 
poses, and of wide application to practically all the forms the 
collector is likely to wish to put up in bottles. 
I now pass to consider methods of histological examination— 
z.¢., the investigation by means of the microscope of the finer 
structure of the fungi. 
We need not dwell on the ordinary cases of direct inspection 
of the collected fungus by means of the pocket-lens or micro- 
scope, except that I wish to emphasize my own conviction that 
just as much valuable work has been done in the past by means 
of the lens and accurate descriptions of the forms gathered 
together and examined at once in the fresh state, so much 
still remains to be done, and certainly some of the finest 
training possible in out-door natural history is obtainable by 
the cultivation of these habits of direct observation in the 
field. Moreover, as we shall see when we come to study 
culture-methods, direct observation of the living fungus yields 
results unattainable by any manipulation of dead forms, however 
well preserved and prepared. 
When all is said and done, however, there remain numerous 
problems only to be solved by the examination of prepared 
material—e.g., questions concerning the nature of the cell-wall 
and contents, nuclei, spore-formation, sexual organs, and so forth 
—and with some of the more minute fungi their very existence is 
hardly demonstrable in the fresh condition. The same applies 
especially to many parasites in vegetable and animal tissues, 
and it is marvellous what striking results can be obtained with 
properly prepared sections, as compared with the rough glimpses 
at the general state of affairs, with which our ancestors had to 
be content. 
I know, moreover, that | am expected to say something as 
regards methods both of staining and of section-cutting, and thus 
to enter on dangerous ground for the amateur ; and at the outset 
you must allow me to express my firm conviction that more time 
can be wasted in this branch’ of work, and more trifling results 
