JAMA. 1933;100(25):2013-2014. doi:10.1001/jama.1933.02740250035013.
Text Size: A A A
Published online

Investigations currently reported by Dr. L. T. Webster1 from the Rockefeller Institute indicate that selective breeding of animals resistant to one microbic disease may inadvertently produce animals hypersusceptible to other infections. The geneticists have pointed out many examples of similar "linkage" between hereditary functions. They would merely assume that hereditary microbic resistance involves a multiplicity of unit factors carried by different chromosomes. The observations have, however, immediate practical interest in their bearing on problems of animal husbandry.

Webster's studies were made on mice reared and maintained for nearly two decades under the most scrupulous hygienic conditions. During this time the herds of mice had never been exposed to microbic infections. The most painstaking examinations had failed to reveal "carrier" conditions. On routine exposure of these herds to standard doses of mouse typhoid bacillus, the mice showed on an average 37.4 per cent herd mortality. The general mouse population, therefore,


Sign In to Access Full Content

Don't have Access?

Register and get free email Table of Contents alerts, saved searches, PowerPoint downloads, CME quizzes, and more

Subscribe for full-text access to content from 1998 forward and a host of useful features

Activate your current subscription (AMA members and current subscribers)

Purchase Online Access to this article for 24 hours

First Page Preview

View Large
First page PDF preview




Meets CME requirements for:
Browse CME for all U.S. States
Accreditation Information
The American Medical Association is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians. The AMA designates this journal-based CME activity for a maximum of 1 AMA PRA Category 1 CreditTM per course. Physicians should claim only the credit commensurate with the extent of their participation in the activity. Physicians who complete the CME course and score at least 80% correct on the quiz are eligible for AMA PRA Category 1 CreditTM.
Note: You must get at least of the answers correct to pass this quiz.
You have not filled in all the answers to complete this quiz
The following questions were not answered:
Sorry, you have unsuccessfully completed this CME quiz with a score of
The following questions were not answered correctly:
Commitment to Change (optional):
Indicate what change(s) you will implement in your practice, if any, based on this CME course.
Your quiz results:
The filled radio buttons indicate your responses. The preferred responses are highlighted
For CME Course: A Proposed Model for Initial Assessment and Management of Acute Heart Failure Syndromes
Indicate what changes(s) you will implement in your practice, if any, based on this CME course.
Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).


Some tools below are only available to our subscribers or users with an online account.

Sign In to Access Full Content

Related Content

Customize your page view by dragging & repositioning the boxes below.