Association AffairsInside AAAS Animal Research Advocate Cited Science 23 Nov 1990:Vol. 250, Issue 4984, pp. 1157DOI: 10.1126/science.250.4984.1157-a Article Info & Metrics eLetters PDF This is a PDF-only article. The first page of the PDF of this article appears above.
Science Vol 250, Issue 498423 November 1990 Table of Contents Print Table of Contents Back Matter (PDF) Ed Board (PDF) Front Matter (PDF)