Perspectives Foreign Invaders See allHide authors and affiliations Science 02 Jul 1993:Vol. 261, Issue 5117, pp. 34-35DOI: 10.1126/science.261.5117.34 Joel W. HedgpethFind 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 261, Issue 511702 July 1993 Table of Contents Print Table of Contents Back Matter (PDF) Ed Board (PDF) Front Matter (PDF)
