FOR WAGGONER’S BIOLOGY 
33 
What part of the fungi are the shelf-like structures? Do you find 
any mycelium? Where? What is the nature of the wood where 
it is present? 
2. Note the shape, the size, the structure, and the attachment 
of the fruiting body. Where are the spores produced? Do you 
find spores? What is their nature? Their abundance? How are 
they scattered? How do the spores find entrance into trees? 
What becomes of most of the spores? What is the value to the 
fungus of the abundance of these spores? 
3. If possible, observe trees which show treatment for wounds. 
Why should wounds in valuable trees be protected? How may 
this be done? How are wounds healed? Note several which have 
healed. What is the danger of leaving a stub of a branch on a 
tree? When removing branches, what precautions should be 
observed? (See Waggoner, Page 179.) What is meant by heart 
rot ”? What does a fruiting body upon an apparently healthy 
tree indicate? 
II. Laboratory Study. With a lens study some of the wood in 
which the mycelium is present. Note the character of the myce¬ 
lium. Also study a tiny'portion of a fruiting body which has been 
mounted under the low power of a microscope. Make drawings 
showing what you see. 
EXERCISE 37 
WHEAT RUST 
Specimens of the various stages of wheat rust (black stem rust) 
should be collected in summer. (These may be found in late 
summer upon volunteer oats, wheat stubble, or rye straw or 
obtained from a biological supply company.) 
I. The Red Rust Stage. Study wheat plants showing the red 
rust stage. What part of the plant is affected? Examine the red 
structures with a lens. What causes the red color? What is the 
age of the wheat plants upon which this stage occurs? (See 
Waggoner, Figs. 113 and 114.) Make drawings as directed by the 
instructor. 
