Abstract
A certain virus was obtained from the spinal fluid of a patient suffering from a benign aseptic meningitis and was found to be of the Dobashi strain. As to etiologic agents of the disease there may be many different organisms, but several viruses except lynphocytic choriomeningitis (LCM) and pseudo-LCM viruses were excluded on the basis of serological reactions and animal experiments. The clinical pictures of mice inoculated with the strain were completely the same to those inoculated with LCM virus described by Rivers and Scott 12) 13) , and the virus were able to pass through Berkefeld N and W candles. However, in the comparing Dobashi strain to the standard LCM virus strain by complement-fixation and cross immunity tests, results were not all favourable in identifying this strain as LCM virus. Incubation periods of the mice inoculated with the strain could be observed to be more or less shorter than Rivers' descriptions and guinea pigs inoculated with the strain did not show typical symptoms as in LCM virus. Therefore it seems to the present authors that the virus is a variety of or closely related to LCM or pseudo-LCM viruses, although the size of the virus is different from that of pseudo-LCM virus 2) .
