Frederick Banting upon the idea of obtaining insulin from the fetal pancreas. He removed the pancreases from fetal calves at a William Davies slaughterhouse and found the extracts to be just as potent as those extracted from the dog pancreases. By December 1921, he had also succeeded in extracting insulin from the adult pancreas. Pork and beef would remain the primary commercial sources of insulin until they were replaced by genetically-engineered bacteria in the late 20th century. In spring of 1922, Banting established a private practice in Toronto and began to treat diabetic patients. His first American patient was Elizabeth Hughes Gossett,
Banting (crater) name the small craters around it with the same name followed by different letters of the alphabet. The new policy allowed deceased scientists who had contributed to biological knowledge, like Dr. Banting – as well as scientists from other fields and contributors to culture and knowledge, such as writers, composers, and artists – to have craters named after them. Previously, only the names of astronomers, others who had made important contributions to astronomy, and historical philosophers had been used. Banting is a "simple" impact crater. It is located in the Sea of Serenity, which is also known as Mare Serenitatis,