Streptococcus Infection Occurring in Ferrets Inoculated with Human Influenza Virus *

The recovery of a filtrable virus from children with influenza has been described in other papers" T,the virus was isolated by means of the intranasal inoculation of ferrets with nasopharyngeal washings. The ferrets reacted to the washings with an acute respiratory infection, followed by recovery. After the virus had been transmitted in series through ferrets for' several generations, the reactions exhibited by many of the animals appeared to be unusually severe, and cultures of the lungs and of the heart blood revealed an invasion with a hemolytic streptococcus. The studies described below are limited in extent, but seem worth reporting for they throw some light on the source of the complicating organism and its role in the experimental virus disease so produced in ferrets.