Letters Reprints Again See allHide authors and affiliations Science 28 May 1965:Vol. 148, Issue 3674, pp. 1173DOI: 10.1126/science.148.3674.1173-a Seymour S. CohenFind this author on Google Scholar Find this author on PubMed Search for this author on this site Article Info & Metrics eLetters PDF This is a PDF-only article. The first page of the PDF of this article appears below.
Science Vol 148, Issue 367428 May 1965 Table of Contents Print Table of Contents Back Matter (PDF) Ed Board (PDF) Front Matter (PDF)