ArticlesAddress THE UNION AND BIOLOGICAL ABSTRACTS See allHide authors and affiliations Science 15 May 1931:Vol. 73, Issue 1898, pp. 517-518DOI: 10.1126/science.73.1898.517 C. E. McclungFind 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.