Describes an experiment that used a four-element radio interferometer to illustrate gravitational deflection as predicted by the theory of general relativity. (MLH)

Briefly describes the ecology of a deciduous forest, and suggests activities for observing and appreciating the changes that occur during the Fall. Simple experiments relating to mosses and lichens are outlined. (JR)

Describes the experimental procedures used for detecting DNA and RNA synthesis in xenopus cells by autoradiography. The method described is suitable for senior high school laboratory classes or biology projects, if supervised by a teacher qualified to handle radioisotopes. (JR)

Discusses research activities conducted by scientists from the United State of America, Canada, and the United Kingdom to determine the long-term effects on natural marine ecosystems, especially plankton communities, of such pollutants as heavy metals, synthetic hydrocarbons, and petroleum hydrocarbons. (CC)

Describes the commercial applications of hydroponics, and then outlines ways in which this soilless plant culture method can be used in the science classroom and laboratory. Gives directions for making a suitable growth solution, and suggests appropriate student experiments involving hydroponics. (JR)

Describes fecal pellet identification as a technique for animal population surveys. (CP)