32 
LABORATORY EXERCISES 
What is the color of the young growth? What is the color of the 
older parts? What is the cause of this color? Where are the black 
objects? How does the fluffy white mass change as it becomes old? 
Note the odor. Why are organic materials which are closed up 
liable to mold readily? 
II. Study some of the mold which has been mounted under the 
microscope. Each thread is a hypha. The whole network of 
hyphce is the mycelium. (Examine with a lens; then examine 
under low power.) What is the nature of the hyphse? Are they 
divided into cells? Are they branched? Compare the hyphse 
(rhizoids) which are beneath the surface of the bread with those 
which are above. 
III. Examine the fruiting body under high power. This is a 
sporangium. Compare the color of the old and young sporangia. 
Why are the older ones so dark? Note the abundance and size 
of the spores which are present. Where are they produced? Ex¬ 
amine a spore case. Estimate the number of spores in a sporan¬ 
gium and the number of sporangia on a growth of mold. 
IV. Draw a mold plant. Show the hyphse, rhizoids, and 
sporangia. Draw a mature sporangium as you see it under high 
power, and also several separate spores. (See Waggoner, Figs. 103 
and 104.) 
EXERCISE 36 
WOOD-DESTROYING FUNGI 
Much of this exercise should be worked out on a field trip by the 
class. If a class trip is impracticable, the work may be done by 
individuals. Specimens may be collected on such a trip which can 
be used for further study in the laboratory. (All the work may 
be done in the laboratory if the weather prevents field work. In 
this case, specimens collected earlier in the year can be used.) 
I. Field Study. 
1. Observe various trees upon which the shelf-like fungous 
growths appear. Where upon the trees are these growths located? 
