GENERAL INTRODUCTION. 
The fungi comprise a very large section of the vegetable kingdom, Being 
destitute of chlorophyll, anil thus differing from the green plants, they are 
unable to utilise the <■ sir bon present in the atmosphere as carbon dioxide. They 
are thus compelled to live a saprophytic, or in some cases a parasitic, existence, 
deriving their supplies of carbon and also other necessary substances from 
organic material which has been formed directly or indirectly from chlorophyll- 
containing plants. In the course of obtaining their food from these various 
sources, they disintegrate the material and break down the complex chemical 
compounds composing it into substances of simpler nature, preparatory to 
building these up again into other forms as part of their own substance. Even 
the parasitic members obtain their nourishment in the same way. Mechanical as 
well as biochemical factors participate in the disintegration. We sometimes see 
bracket fungi growing on telegraph posts, or the rails of a fence, or on the 
prostrate trunk of a forest tree. These are the fruiting bodies of fungi wliose 
mycelial threads permeate the adjacent wood where their presence can be 
recognised by the altered appearance and texture. The affected portion is easily 
broken down and readily crumbles. Part of the air-spaces that were present in 
the dead wood have become tilled by the fungous threads, so that the wood now 
smoulders on the fire instead of burning freely. With access of moisture, the 
mycelial threads become turgid and so tend to rend asunder the wood fibres 
in their neighbourhood, and in addition ferments are secreted by the growing 
mycelium which lead to chemical disintegration as well. When in the 
forest the trunk of a tree falls to the ground and wet weather supervenes, fungi 
of various kinds and bacteria invade the dead material, gradually permeate it, 
and in the ways mentioned lead eventually to its complete disintegration, being 
aided in the process by other lowly forms of life, and by insects and related 
animals. With warmth, the process is hurried up, if sufficient moisture be 
present so as to give a. humid atmosphere; with cold it is retarded, and in the 
relative absence of moisture it is arrested or nearly so. In. the arid interior of 
Australia, unless attacked by termites, the destruction of timber is exceedingly 
slow, whilst in a t ropical jungle a great tree that has fallen may disappear 
entirely in a surprisingly short time. Were it not for this beneficent disin- 
tegration by fungi and bacteria, the forest floor would soon become deeply 
littered with fallen boughs and leaves and a rich humus would fail to develop. 
Seedling plants would not find room to grow, and in the course of time the 
forest itself would necessarily cease to exist. Fungi, aided by bacteria, are 
then the great scavengers of the forest and of effete plant material as a whole, 
just as bacteria aided by insects are, under natural conditions, the chief means 
of removing animal carcases. The forest tree is like Imperial Caesar, and the 
“clay’' to which each is turned serves an ever-useful purpose and is again built 
up to form forest-trees and Caesars of a younger generation. 
It is not the purpose of this Handbook to deal with the great group of fungi 
as a whole. This would be a stupendous task, even dealing with the South 
Australian members alone. There are so many branches, and the work in each is 
so specialised, that the various divisions would require to be dealt with by 
separate workers. It is advisable, however, to indicate briefly what these 
different divisions are, so that we may appreciate more clearly the relationship 
borne by our special subject to its allies in mycology. The bacteria are closely 
related to the fungi and pass by almost imperceptible gradations from unques- 
tioned bacteria to quite obvious fungi. To the bacteriologist dealing with 
human, animal, or plant diseases, or with the bacteriology of the soil, or the 
maturing of tobaceo, or the making of butter, or the tanning of leather, or 
even the manufacture of white lead, we leave the bacteria. To one of his tribe 
wo leave also the study of such true fungus diseases of man as ringworm and 
thrush, as well as the yeasts, also true fungi, that make our bread rise or brew 
our beer. This Handbook will not deal either with the many kinds of moulds 
that grow on damp bread, that cover our boots in the tropics, or cause patches 
and decay on tarpaulins, or sometimes disfigure the carcases of meat in cold 
storage. These fungal organisms and their allies are many, most are minute 
and require microscopic study to appreciate them at all, their structure as fungi 
