Further Studies concerning the Filtrable Virus Present in the Submaxillary Glands of Guinea Pigs

1. It has been shown that the guinea pig virus localizes in the submaxillary glands of young guinea pigs following subcutaneous, intraperitoneal, or intravenous injection of active material, and that the specific lesion is demonstrable in the glands in 12 to 15 days. When an active infection of the gland has been produced in this way, the guinea pigs are refractory to intracerebral inoculation of the virus. 2. No lesion develops in the submaxillary glands of young guinea pigs injected subcutaneously with guinea pig virus which has been inactivated by heat. Young guinea pigs which have received injections of heat-killed virus do not become refractory to intracerebral inoculation of the virus. 3. When young guinea pigs from which both submaxillary glands have been removed are injected subcutaneously with active virus, the virus localizes in the parotid gland, and the animals become refractory to intracerebral inoculation. 4. It has been impossible to demonstrate virucidal properties in the sera of adult guinea pigs which have become spontaneously infected with the virus, or in the sera of young guinea pigs which have been artificially rendered refractory to intracerebral inoculation. 5. It has been possible to transmit the virus from guinea pig to guinea pig continuously in series through seven animals by direct inoculation from submaxillary gland to submaxillary gland. 6. The fact that the virus regularly localizes in the submaxillary glands following subcutaneous inoculation has been utilized in passing the virus from guinea pig to guinea pig. 2 weeks after the subcutaneous inoculation of the virus into young guinea pigs, the active agent was present in the submaxillary glands. Emulsions of the submaxillary glands of these animals were then used for the subcutaneous injection of another group of young guinea pigs. In this way the virus was transmitted continuously from skin to submaxillary gland through a series of seven animals.