A -- Main Lectures.- Inaugural Address, Congress of Primatology, Florence.- Recent Advances in Molecular Evolution of the Primates.- Immunogenetic Evolution of Primates.- The Evolution of Human Skin.- The Importance of Theory for Reconstructing the Evolution of Language and Intelligence in Hominids.- Primatology and Sociobiology.- Dominance and Subordination: Concepts or Physiological States'.- Sexual Behavior in Aging Male Rhesus Monkeys.- Simian-type Blood Groups of Hamadryas Baboons. Population Study of Captivity-born Animals at the Sukhumi Primate Center -- Preliminary Report.- Rhesus Macaques: Pertinence for Studies on the Toxicity of Chlorinated Hydrocarbon Environmental Pollutants.- The Role of a Kenyan Primate Center in Conservation.- Further Declines in Rhesus Populations of India.- Taiwan Macaques: Ecology and Conservation Needs.- Prospects for a Self-sustaining Captive Chimpanzee. Breeding Program.- B -- Symposium Reports.- Miocene Hominoids and New Interpretations of Ape and Human Ancestry.- Infanticide in Langur Monkeys (Genus Presbytis): Recent Research and a Review of Hypotheses.- Recent Advances in the Study of Tool-Use by Nonhuman Primates.- Primate Communication in the 1980s: Summary of the Satellite Symposium on Primate Communication.- Primate Locomotor Systems: Summary of Results of the Pre-Congress Symposium in Pisa.- Results of the Pre-Congress Symposium on "Methods and Concepts in Primate Brain Evolution".- The Effects of Drugs and Hormones on Social Behavior in Nonhuman Primates.- Report on Symposium Entitled: "Comparative Biology of Primate Semen".- Chromosome Banding and Primate Phylogeny. Inaugural Address.- Comparative Psychology Symposium: Introduction.- The Present and Future Status of Comparative Psychology: Proceedings of the Corigliano Calabro Symposium.