Letters Letters to the Editor By Donald O. Walter See allHide authors and affiliations Science 19 Dec 1969:Vol. 166, Issue 3912, pp. 1459DOI: 10.1126/science.166.3912.1459-d Donald O. Walter 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.
Science Vol 166, Issue 391219 December 1969 Table of Contents Back Matter (PDF) Ed Board (PDF) Front Matter (PDF)