SUMMARYIn April 1964, 15 1-kg. packages of honeybees shaken from colonies infected with European foul brood and 15 1-kg. packages shaken from non-infected colonies were transported 1300 km. and installed in sterile equipment with new frames and foundation. All colonies derived from infected colonies developed E.F.B., whereas all those derived from non-infected colonies remained healthy. The disease did not appear until 5 weeks after packages were hived, and therapeutics given as soon as packages are installed should prevent build-up of infection to a level that causes disease.