“…The virus of herpes simplex (HSV) was isolated in experimental animals as long ago as 1920 (Gruter 1920, Lowenstein 1919. The method of corneal scarification leading to keratoconjunctivitis in rabbits and guinea pigs is now mainly of historical significance, but mice, and more particularly suckling mice which are highly susceptible to the virus after intracerebral inoculation, are still used for virus isolation (Table I).…”