Articles Science Teaching Improvement Program See allHide authors and affiliations Science 21 Nov 1958:Vol. 128, Issue 3334, pp. 1262-1265DOI: 10.1126/science.128.3334.1262 John R. MayorFind 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.