Letters Letters to the Editor By William Voigt Jr. See allHide authors and affiliations Science 19 Jul 1968:Vol. 161, Issue 3838, pp. 219DOI: 10.1126/science.161.3838.219-a William Voigt Jr.Find 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 above.