The lactic dehydrogenase agent (LDH agent) was found in the urine, feces, and saliva of mice within 24 hours after inoculation. The titer of virus in these materials appears to be directly related to the titer in the plasma. Infection by the oral route occurred only when a high concentration of virus was used.
Animals infected prior to mating rarely transmitted the LDH agent to their progeny. However, 91.2 per cent of the progeny of mothers infected during gestation and 51.5 per cent of the progeny of mothers infected within 48 hours after giving birth became infected with the LDH agent. Evidence is discussed which suggests that the transmission of the LDH agent from the infected mother to her offspring is related to the titer of the LDH agent in the maternal circulation.