Briefly discusses the theory of fatigue, and describes ways in which the fatigue rate in humans can be measured in the classroom using a simple physiological instrument, the ergometer. (JR)

Describes how the continuous variation method may be used in senior chemistry classes at the secondary level. This technique allows for the detection of the one or more reactions that may occur in a system over a wide range of composition. (JR)

Describes student activities with mercuric oxide and mercury that help them to form models of the solar system and its creation. (JR)

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)

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

Discusses the importance of ethene (ethylene) in industry and the pipeline grid in western Europe for transporting ethene. Describes methods for investigating organic compounds in school laboratories using ethene as the key compound. (JR)

Discusses holography, a process by which a three-dimensional image of an object can be completely recorded on a photographic film or plate. Introduces hologram theory with a view to presenting it to senior high school students, and explains how the apparently very great experimental difficulties can be overcome. (JR)

Describes animal behavior experiments that can be easily performed by secondary school students. The experiments illustrate territorial behavior, social order, and exploratory behavior in Mongolian gerbils. (JR)

Describes demonstrations suitable for secondary school biology classes relating to the effects of the hormone IAA on plant growth. Demonstrations illustrate how hormone treatments affect stem elongation, callus formation, inhibition of axillary buds, stimulation of secondary growth and initiation of adventitious root development, root elongation,…