Studies on Measles

Summary 1.The agent of measles, obtained from the blood or pharyngeal washings of human cases, has been propagated by serial passage on the chorio-allantois of the fertile hen9s egg in the absence of regularly occurring, transmissible, macroscopic lesions. 2.The presence of the agent has been demonstrated by the inoculation of pooled chorio-allantois and viscera of the chick embryos into monkeys ( Macacus mulatta ) with the production of a disease indistinguishable from that brought about by the injection of material obtained from cases of human measles. 3.From monkeys infected with material from either source, measles virus can be isolated from the blood and nasal washings during the period of acute disease and again propagated in the fertile hen9s egg. 4.Certain properties of the virus have been elucidated during the course of the work.