To answer these questions many experiments and demonstrations must be made. Again, in the study of the local water system, determine the uses now made of water and the benefits and dangers of the system, construct models of mechanical devices used in the system for securing and delivering water and for disposal of wastes, etc. The following list of subtopics will suggest the content of the whole topic: The common uses of water; local dangers of contamination; sources of supply in use and possibilities for extension of system; relation to public health with typhoid as an illustration; sewage, its uses and dangers.

B. Methods. The foregoing discussion of selection and organization suggests the point of view in presentation. Topics should be large units. At the outset the topic should be viewed briefly as a whole for the sake of perspective. Such a general view gives a concrete and significant basis to which there should be constant return and to which further and more detailed and more exact studies should be constantly related.

A combination of class presentations of out-of-school experiences, of individual laboratory work, and of teacher-and-pupil demonstrations is desirable. Simple materials should constitute most of the laboratory apparatus. The desk demonstration by teacher or pupils is excellent as a means of presenting an experiment for observation and discussion so that the attention of all may be definitely directed to the question in mind. Pupil demonstrations and individual laboratory work also should be used, since they give individual opportunity to handle apparatus and opportunities for active participation by each pupil. There is no objection to the same problem being solved by the whole class as individuals or as groups, provided that the class as a whole feels the importance of the work; but care must be taken when assigning the same task to all to see that the work does not become meaningless for some. Sixty-minute laboratory periods are generally better than longer periods for introductory science courses. An abundance of textbook and other reading matter should be available.

No text in general science can or should supply answers to all inquiries. The textbook should be used as a reading and reference book, and other sources for reading should be extensively used, such as magazine articles which deal with current use of science. References should be specific for children of the age of general science pupils, since they will gladly do much reading if they know just what to read.

Bulletins of available current reading matter prepared by teachers and pupils are an aid in reference work, and are stimulating to teacher and pupil.

Excursions, well directed and with a purposeful plan, are of great value. Excursions should always be definitely planned, carried out as serious exercises, and the results used in later work. Pupils and teacher should look upon excursions as a regular part of the serious work of the course.

C. Sample topics.-It is not desirable that there should be a syllabus to which teachers shall adhere, but instead enough topics should be presented as illustrations to indicate clearly the kinds of materials recommended., The topics here presented are based upon those actually used in a high school in a city of approximately 150,000 inhabitants. In other schools--for example, a school in a strictly agricultural community-many changes would naturally be made. In the city from which this outline is selected the course varies from year to year according to the topics on which emphasis is needed.

Topic 1. Combustion.-Why our homes must be heated at times and cooled at other times; sources of heat; kinds of fuel; making a bonfire; list of questions about bonfires; why the fire burns; lesson on elementary chemistry-elements and compounds; what becomes of wood when burned; oxidation; why stones are not used for fuel; heat produced by oxidation; making a thermometer; effects of heating iron, water, wood; slow heating of water; thermostat; how heat travels; ways for heating a home; how the science room is heated; study of a chimney; what smoke is; how common illuminating gas is made; properties of illuminating gas; how gas is made in this city; study of candle flames; study of Bunsen burner and its use; carbon dioxide how produced; body fires-relation to physiology; control of fires; losses from fires and how to prevent them; what is a fire insurance company; does the insurance rate in this city indicate that fires are more common here than elsewhere?

Topic 2. Water.-Three forms of water; how used in home and school; changes from one to another; relation of heat to these changes; changing water to steam; evaporation; ice machines; changing vapor to water; condensation; dew; rain; frost; snow; distillation and applications; transpiration; running water; where from, where going, and why; rate of flow; erosion and its effects; erosion and forests; erosion and crops; erosion and farm values; influence of bodies of water on climate; fruit belt about large bodies of water; composition of water; analysis and synthesis; water in relation to health problems; distribution of bacteria; typhoid as illustration; water supply and sewage disposal in this city; source of water; impurities; filtration; water system; sewers; various methods for disposal; the one used in this city; industrial uses of water; water a solvent; relation to household use; relation of this to plant and animal life;

uses of water in industries; relation of water to geographic location of industries; water pressure as used in machines.

Topic 3. The air and the weather.-Does air occupy space? Why can you kick a football farther when it is inflated than when empty? Does air have weight? determination of weight of air in classroom; air pressure; common pump; meaning of pressure barometer; biography of Galileo and Torricella; story of making first barometer; distinction between weight and pressure; moisture in air; effect on weight of air; relation of temperature and atmosphere to moisture in air; dew point; frost, rain; dew; air pressure and winds; highs and lows; weather map; what it is designed to show; how forecasts are made; rainfall map; importance of rainfall; composition of air; impurities in the air.

Topic 4. Light and its benefits.-Why and how things are visible; intensity of illumination; measuring the light; reflection; refraction; color, photography; artificial lighting; benefits of light; sunlight and health.

Topic 5. Work and energy.-Work by running water; machines; mills run by water power; pumps run by water power; elevators run by water power; gasoline engine; biography of James Watt; Mechanical energy and heat.

Topic 6. Magnetism and electricity.-Frictional electricity; a magnet; earth magnetism, the compass; a battery, kinds of batteries; current electricity, heating effects, household appliances; chemical effects of electricity; electroplating; magnet effects, electro magnets, electric bell, telegraph, motors; induced currents, dynamo, telephone. Topic 7. Nature's balance of life.-Meaning of possible overproduction as shown by calculations of possible numbers of new individuals; rabbit; fox; wolf; potatoes; limiting conditions; why some forms stay and others do not; biography of Charles Darwin; artificial selection; good seed and poor seed and the results; germination; soil as source of plant food; subtraction and addition of soil elements; why a plant needs water; how water rises through the soil; how liquid goes from cell to cell; food factories for all living things; leaf structure; light and chlorophyll; products and byproducts; air for plants; public parks and city trees; birds and their food in relation to balance of life; migration in relation to balance of life; protection; plant reproduction; structure of flower; seed distribution of dispersal; seed of burdock in relation to balance of life; the problems of successful living.

NOTE.-Most teachers of general science have found it wise to use several topics in addition to those included in the above list, the above being merely suggestive of the types of topics recommended.

II. BIOLOGICAL SCIENCES.

A. Place of biological sciences.-The biological sciences now taught in high schools are general biology, botany, zoology, physiology, hygiene, and sanitation. These subjects do not represent the full extent of differentiation, since there is a tendency toward further specialization within some of these subjects. Investigation shows also that in some four-year high schools any one of these subjects may be elected by any pupil in any semester. The length of time given to a biological course ranges from one-third of a year in some schools to two years in other schools. An investigation of a large number of four-year high schools in a wide range of localities indicates a distinct tendency toward a sequence of courses consisting of a general science course offered in the first year of the four-year high school followed by the biological subjects in the tenth grade. In a few States there is a tendency to have biology given as the science of the first year of the four-year high school. In junior-senior high schools the tendency is to require a course in general science followed by a course in general biology in the junior high school, with opportunity for the election of special courses in botany and zoology as well as other sciences in the senior high school. It is recommended that in four-year high schools a course in biology be given in the second year and that in the junior-senior high schools this subject be given in the last year of the junior high school, and that in large schools other biological sciences be offered as electives in later years of the high school.

B. Changes in the point of view in biological teaching.—When biology was introduced into the secondary school, the subject was taught by men and women trained almost wholly in college courses in morphology and classification; and in consequence a diluted type of college course was almost inevitable in the high school. Much of the laboratory material consisted of preserved specimens of plants and animals. Microscopical work of too difficult a type was insisted upon. Herbaria of dried specimens cluttered home and school.

In recent years increasing emphasis has been placed on the study of living organisms. Physiological experiments and ecological studies have been introduced. But still the type of topic selected for study is more or less that which appeals to the adult mind rather than to the mind of the adolescent. The material used was often remote from the every day experience of the students, and biological studies still failed to function as largely as had been hoped.

When teachers began to present biology in its relation to human welfare, a new and vital interest in the subject was awakened, and in many schools biology has become deservedly popular. It is evident that further progress in the pedagogy of the subject should be

inade along the line of organization of courses in biology which relate to various aspects of human welfare.

C. Aims.-Biological sciences, in common with the other sciences in secondary schools, should contribute to the educational objectives stated on page 12-health, worthy home membership, vocation, citizenship, the worthy use of leisure, and ethical character. In particular, biological sciences should have the following specific aims:

(1) The World War has emphasized health as a basic end of education. Since much of biology deals directly with problems of health, the course in biology must accept efficient health instruction as one of its chief and specific ends.

(2) The biological sciences should develop the pupil's purposeful interest in the life of the environment by giving a first-hand acquaintance with plant and animal neighbors.

(3) They should emphasize some of the most important applications of biological science to human activities and to general and individual human welfare, and especially should familiarize the pupil with the structure and functions of his own body, to the end that he may know why he must live healthfully in order to live happily and usefully.

(4) They should train the upil to observe life phenomena accurately and to form logical conclusions through the solution of problems and through projects essential to the productive work of agriculture, gardening, etc.

(5) They should enrich the life of the pupil through the æsthetic appeal of plants and animals studied, to the end that he may appreciate and enjoy nature.

(6) They should demonstrate to the pupil the value of intensive study of biological science as a means through which scientific progress is attained. In view of what science has meant to our present day civilization and in view of the measure in which the methods and results of scientific investigation are to-day reflected in intelligent thought and intelligent action, the need of the life sciences in the education of modern citizens can not be ignored.

D. Sequence and continuity.-The sequences recommended in Part I of this report provide for (1) one year of general biology for all pupils in the second year of four-year high schools and in the last year of junior high schools, (2) the election of courses in botany. zoology, and physiology in the third or fourth year of four-year high schools and in any year in senior high schools. The intricate and detailed study of those abstractions that are more difficult for the pupil to understand and appreciate will thus be left for the special biological courses in the later high-school years, and may then be elected by those who have special interests and needs.