An official website of the United States government
Here's how you know
Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
As a library, NLM provides access to scientific literature. Inclusion in an NLM database does not imply endorsement of, or agreement with,
the contents by NLM or the National Institutes of Health.
Learn more:
PMC Disclaimer
|
PMC Copyright Notice
aLaboratories of the Rockefeller Institute for Medical Research, New York
1
Read before the Forty-first Anniversary Meeting of the Society of American Bacteriologists, at St. Louis, Missouri, following the presentation of the Eli Lilly and Company Research Award in Bacteriology and Immunology for 1940.