Anglo-American development 3. British development was initiated in 1940, and had achieved promising results by the time the U.S.A. entered the war. Larger scale research including the study of production problems, was subsequently undertaken in the U.S.A. 4. The following are examples of B.W. agents:(a) Anthrax spores Pilot production was achieved and full-scale plant exists in America. This agent has good storing properties, and can probably survive in charged weapons for at least six months without appreciable deterioration.