LettersDiscussion and Correspondence THE GEOGRAPHIC DISTRIBUTION OF HYBRIDS By M. L. Fernald See allHide authors and affiliations Science 22 Jul 1921:Vol. 54, Issue 1386, pp. 73-74DOI: 10.1126/science.54.1386.73 M. L. Fernald 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.