REFERENCES 
327 
another organism. As they lack chlorophyll, fungi cannot 
use carbon dioxide, and as a result that which they produce 
by respiration is cast off into the air, as is the case with 
animals and with green plants placed in the dark. 
The fungi which are most important economically are the 
yeasts used in making bread, or beer and other fermented 
liquors; the edible mushrooms; those that spoil food, as 
bread mold, and those which cause plant diseases, such as 
corn smut and wheat rust. Fungi reproduce by means of 
spores. The mutually helpful relation in which fungi and 
algse live in the lichen is called symbiosis. 
QUESTIONS 
What is the color of fungi ? Are they ever green ? Why not ? How- 
does their food differ from that of green plants? How does the yeast 
plant produce changes in flour? How does the work of bread mold and 
yeast compare with that of a green flowering plant ? What are lichens ? 
Do lichens grow equally well on all sides of a tree ? on all trees ? How 
do they appear when wet? when dry? What colors do you find 
among them? 
REFERENCES 
Atkinson, High School Botany. 
Atkinson, Mushrooms. 
Bennett and Murray, Cryptogamic Botany. 
Cook and Berkley, Fungi. 
Gibson, Our Edible Toadstools and Mushrooms. 
Marshall (The Nature Library), Mushrooms. 
Trouessart, Microbes, Ferments, and Molds. 
