The American pathologist and virologist Francis Peyton Rous (1879-1970) received the Nobel Prize in medicine for his pioneering work on the relation of viruses to cancer.

Peyton Rous was born in Baltimore, Md., on Oct. 5, 1879. He attended Johns Hopkins University in Baltimore, from which he received a bachelor's degree in 1900 and a medical degree in 1905. From 1905 to 1906 he served as resident house officer at the Johns Hopkins Hospital and from 1906 to 1908 was an instructor in pathology at the University of Michigan. In 1909 Rous went to the Rockefeller Institute for Medical Research in New York City, where he remained until his death on Feb. 16, 1970.

At the Rockefeller Institute, Rous began a series of studies of tumors in chickens. It was then widely believed that cancers were caused by chemical agents and that they could be transmitted from one animal to another only through the actual transplantation of cancerous cells...