(vĭv´´ĭsĕk'shӘn), dissection of living animals for experimental purposes. The use of the term in recent years has been expanded to include all experimentation on living animals, rather than just dissection alone. The practice contributed to the outstanding progress that was made in the 17th cent. by William Harvey in understanding the circulation of the blood. However, the use of research animals in the laboratory did not become widespread in Europe until the 19th cent. In 1896, when the National Institute of Health originated in the United States, it began to take an active role in encouraging proper care and use of laboratory animals. Since 1945, the National Society for Medical Research has tried to explain to the public the nature and necessity of experimental procedures on animals. During the 1980s, the incidence of vandalism, harassment, and theft in research centers using animals for testing increased greatly. Most nations have government agencies that assume advisory or…