Direct immunofluorescence examination for rabies virus antigen was performed on cranial nerves, face skin and other tissues excised from experimentally inoculated goats and dogs and naturally infected skunks. The cranial nerves of those animals with limited fluorescence in nerves of the skin also contained only limited amounts of rabies virus antigen; the cranial and peripheral nerves of naturally infected skunks had large amounts of antigen. All the cranial nerves checked in the experimentally inoculated animals had virus antigen at points close to the brain. Limited fluorescence in the peripheral nerves of rabid animals has been associated with the short incubation period often experienced with experimentally inoculated animals, with the exception of the goat. The incubation period is related to the degree of susceptibility of the new host, the quantity of virus, the route of infection and the degree of adaptation of the virus to the new host.