1] Introduction to Fungi 13 
Those resulting from fertilization usually serve to 
carry the fungus through bad conditions, such as winter. 
They are known as “‘winter” or “resting” spores, and 
some are capable of living for several years. 
Many plants have other methods of reproduction 
besides seed, e.g. potatoes are usually derived from 
tubers in underground stems. Certain fungi have very 
similar methods. Portions of the mycelium of the 
potato disease fungus are capable of living in the potato 
tuber and of producing a further growth of mycelium 
and spores. 
Mushroom spawn is capable of producing mushrooms 
because it contains the mycelium of the fungus. 
Parasitic fungi live in much the same way as those 
which grow on bread. The plant which is being 
attacked is known as the “host.” The mycelium 
usually lives inside its host and absorbs the food 
materials found there; it appears on the surface only 
for the purpose of forming spores. The visible portions 
of the fungus are the organs of reproduction and the 
parts of the mycelium bearing them. In the case of 
the true mildews, however, almost the whole of the 
fungus is on the outside and the food is obtained by 
suckers called ‘“‘ haustoria”’ penetrating into the plant. 
Fungoid diseases are spread from one plant to 
another chiefly by means of spores which may be 
blown about in the air or carried by insects; some 
spores can live for a long time in the soil and infect 
plants sown there. In other cases the mycelium 
itself is capable of infecting plants by growing through 
the soil from one plant to another. 
Enormous losses result from fungus attacks, but 
the harm done by a particular fungus varies from year 
