Presents an outline of current knowledge relating to the response of radicles to a directional source of water (hydrotropism). New techniques are described that may be used in biology classes to demonstrate the hydrotropic response in plants. (JR)

Outlines the advantages of using the readily available eggs of the nematode Rhabditis in studying the early cleavage stages of animal development. Discusses the identification and life history of Rhabditis, how to culture and examine the organism, the cleavage stages and cell lineage, and sources of visual aids. (JR)

Discusses phenomena relating to the nature of soap films and describes soap film experiments suitable for secondary school science students. (JR)

Discusses an experiment which introduces students to the effects of electrical forces on the motion of macroscopic objects. Included are the proecedures of measuring the charge-to-mass ratio from deflections of charged water drops in horizontal fields and the overall charges delivered in a Faraday cup. (CC)

Describes an activity using simple materials that gives students an opportunity to express their ideas about possible extraterrestrial life forms. (JR)

Describes how student understanding and interest in the metric system system can be stimulated by building and launching model rockets. (JR)

Describes several experiments, suitable for secondary school biology classes, using the bioluminescent marine bacterium, Achromobacter fischeri. (JR)

Describes the characteristics of Colpoda, a ciliated protozoan which is able to survive in a dry, encysted state for long periods of time. Outlines the procedures for culturing the organism and producing cyst preparations, and recommends its use in the high school biology laboratory. (JR)