Home experiment.—Conditions favorable for growth of yeast.
Home experiment.—Conditions favorable for growth of yeast in bread.
Demonstration and experiment.—Where bacteria may be found.
Demonstration.—Methods of growth of bacteria, pure cultures and colonies shown.
Demonstration.—Foods preferred by bacteria.
Demonstration.—Conditions favorable for growth of bacteria.
Demonstration.—Conditions unfavorable for growth of bacteria.
Demonstration by charts, diagrams, etc.—The relation of bacteria to disease in a large city.
colorless plants are useful and harmful to man
The Fungi.—We have found that green plants on the whole are useful to mankind. But not all plants are green. Most of us are familiar with the edible mushroom sold in the markets or the so-called "toadstools" found in parks or lawns. These plants contain no chlorophyll and hence do not make their own food. They are members of the plant group called fungi. Such plants are almost as much dependent upon the green plants for food as are animals. But the fungi require for the most part dead organic matter for their food. This may be obtained from decayed vegetable or animal material in soil, from the bodies of dead plants and animals, or even from foods prepared for man. Fungi which feed upon dead organic material are known as saprophytes. Examples are the mushrooms, the yeasts, molds, and some bacteria, of which more will be learned later.