Eighteenth and nineteenth weeks. THE NATURAL RESOURCES OF MAN: SOIL, WATER, PLANTS, ANIMALS. The relation of plant life to the above factors of the environment. The relation of insects to plants (forage and other crops) and the relation of birds to insects. Need for conservation of the helpful factors in the environment of plants. Attention called to some native birds as insect and wood destroyers. Twentieth week. REVIEW AND EXAMINATIONS. SECOND TERM First week. THE BALANCED AQUARIUM. Study of conditions producing this. The role of green plants, the role of animals. What causes the balance. How the balance may be upset. The nitrogen cycle. What it means in the world outside the aquarium. Symbiosis as opposed to parasitism. Examples. Second week. STUDY OF THE PARAMOECIUM. Study of a hay infusion to show how environment reacts upon animals. Relation to environment. Study of cell under microscope to show reactions. Structure of cell. Response to stimuli, function of cilia, gullet, nucleus, contractile vacuoles, food vacuoles, asexual reproduction. Drawings to show how locomotion is performed, general structure. Copy chart for fine structure. Third week. A BIRD'S-EYE VIEW OF THE ANIMAL KINGDOM. One day. Development of a multicellular organism. (Use models.) One day. Physiological division of labor. Tissues, organs. Functions common to all animals. Illustrative material. Optional trip to museum for use of illustrative material to illustrate the principal characteristics of (_a_) a simple metazoan, sponge, or hydrazoan, (_b_) a segmented worm, (_c_) a crustacean (Decapod), (_d_) an insect, (_e_) a mollusk and echinoderm, (_f_) vertebrates. (Differences between vertebrates and invertebrates.) The characteristics of the vertebrates. Distinguish between fishes, amphibia, reptiles, birds, mammals. Two days for discussion. Man's place in the animal series, elementary discussion of what evolution means. Fourth week. THE ECONOMIC IMPORTANCE OF ANIMALS. Uses of animals: (1) As food. Directly: fish, shellfish, birds, domesticated mammals. (2) Indirectly as food: protozoa, crustacea. (3) They destroy harmful animals and plants. Snakes--birds; birds--insects; birds--weed seeds; herbivorous animals--weeds. (4) Furnish clothing, etc. Pearl buttons, etc. (5) Animal industries, silkworm culture, etc. (6) Domesticated animals. Animals do harm: (1) To gardens. (2) To crops. (3) To stored food; examples, rats, insects, etc. (4) To forest and shade trees. (5) To human life. Disease: parasitism and its results,--examples, from worms, etc.; disease carriers fly, etc. Preventive measures. Methods of extermination. References to Toothaker's _Commercial Raw Materials_. Use one day for laboratory work from references.