The published proceedings of most symposia are disappointing on several counts. Happily, this record of the 1968 Rochester Conference on Toxicity is not ill organized, outdated, overedited, or even underindexed. The 26 presentations range from specific research reports on pesticide toxicology to reviews on the consequences of our dependence on biocides. The discussants focus on organomercurial and chlorinatedhydrocarbon pesticides, all of which are biologically active, chemically stable, and physically mobile. These characteristics account for the universal contamination by DDT a mere quarter century after it became available commercially. The candid, often pointed, discussions following each paper and during two special sessions contribute greatly to the volume. Recurring subjects include the role of birds as sentinels of environmental poisoning, toxicological problems of pesticide synergisms, direct and indirect effects on nontarget organisms, pesticide-induced hormonal imbalances with attendant reduction in reproductive success, and the inadequacy of government to protect our environment as well