30 TEACHING SCIENCE IN SECONDARY SCHOOLS

 Teachers of Elementary Science, by Hudspeth, and in
 the service bulletins of many supply houses.
 7. Insist on cleanliness and orderliness in the laboratory.
 Start with clean equipment and quarters at the begin-
 ning of school. Set the example of neatness and efficiency
 yourself. A final cleanup of the laboratory is imperative
 at the close of the school year.
 8. Encourage students to make all possible varieties of
 equipment for the laboratory and for their own projects.
 Examples: plant presses, insect drying boards, cyanide
 jars, nets, aquaria, terraria, specimen cases and cages.
 9. How much dissection? The question has many answers.
 A conservative policy is as follows: (a) dissect plants
 freely, and in all plant structures; (b) offer more com-
 plex dissections on larger animals as teacher's demon-
 strations; (c) limit animal dissections to earthworms,
 crayfish, insects, fish, and frogs; (d) give tactful atten-
 tion to the feelings of a "squeamish" student.
 Often the dressing of familiar food animals, such as
 chickens, or fish, at home will furnish interesting back-
 ground for laboratory dissection.
 10. Embryology should be studied by examination of suc-
 cessive embryos of chicks in nest or incubator.
 11. Keep up with the new techniques of laboratory prepara-
 tions, such as the use of plastics in preserving specimens.
 12. Large classes introduce serious handicaps to good teach-
 ing of biology. If possible, keep the classes and the lab-
 oratory sections to sizes convenient for the type of in-
 struction recommended above. If this is not possible,
 work out various schemes for sectioning inside your
 class, with certain students reading while others experi-
 ment, and still others work on individual projects. In
 recitations use individual responses of students as far as
 possible, requiring the full attention of all other students.
 Let's go outdoors! Journeys into the field are for two pur-
 poses: (1) observation, and (2) collection.