Reported are three case histories of children with congenital head nodding and nystagmus (rhytmic oscillation of the eyeballs) associated with brain degeneration and motor and mental retardation. (DB)

Discusses the mechanisms of genetic recombination with particular emphasis on the study of the fungus Sordaria brevicollis. The study of recombination is facilitated by the use of mutants of this fungus in which the color of the ascospores is affected. (JR)

Discusses the basis of the theory of preformation used in teaching heredity and development. English translation of the original document written by Hartsoeker is included that reveals the theory was an imagined one without concrete evidence. (PS)

Topic 8, Our Contemporary World: Problems and Issues, in a theme issue on Teaching World History Through Science Fiction, presents a story from Startling Stories, published in 1946, to motivate discussion on factors contributing to a generation gap. (JB)

Discusses the moral and ethical issues raised by the imminent possibilities for genetic and reproductive manipulation of humans, the responsibilities of scientists, moralists, and social scientists, and the role of teachers in public information. (AL)

Presents genetical and biochemical data to show that the conclusion presented by Dyer (EJ 036 108) is by no meas settled. Evidence to support the concept: evolution by selectively neutral polymorphisms is inconclusive. (AL)

Reported are seven cases in two families of the Meckel syndrome, whose key features are occipital encephalocele, cleft lip and palate, polydactyly, and polycystic kidneys. Evidence supports the hypothesis that the syndrome is a recessively inherited condition, determined by homozygous expression of a single autosomal gene. (Author/KW)