1] Introduction to Fungi 9 
organic matter, no mushrooms will form. This is 
because the mushroom does not live like a green plant, 
but requires organic matter for its food. 
Remove the stalk of a ripe mushroom and place 
it with the coloured part downwards on a piece of white 
paper and leave it for some time. Then tap it gently 
and lift it; on the paper will be found a print similar 
to the gills or coloured part of the mushroom which is 
found to consist of coloured spores (see Fig. 7). These 
are borne in pairs on some of the cells on the sides of 
the gills. The mushroom is the spore-bearing part of 
the fungus and it can be produced from these spores 
as well as from spawn. Toadstools similarly bear 
spores. 
So far we have been growing the fungi on dead 
materials and dealing only with saprophytes. Para- 
sitic fungi can be obtained by growing plants under 
suitable conditions for fungus attacks. Sow cress 
seed in a pot of soil, keep the soil very wet and in a 
fairly warm atmosphere. The young seedlings soon 
wilt and die. Examination of the surface of the soil 
shows a ramifying growth of mycelium, some of which 
has entered the plant. Here, then, we have a case of 
a fungus capable of injuring a plant and therefore a 
parasite, but it is also capable of living on the soil as 
a saprophyte. There are many others besides this one 
capable of living either as saprophytes or parasites. 
Some however can live only as saprophytes, e.g. 
Penicillium, and others only as parasites, e.g. rusts. 
In a previous experiment we simply moistened a 
piece of bread, and on leaving it found that fungi began 
to grow. How did these get on the bread? The fol- 
lowing experiment affords an answer. Take a piece 
