This fixed strain was discovered accidentally in our laboratory during experimenting the intravenous infection with various kinds of rabies virus. The experiment was made on the rabbits and carried out with passed and fixed viruses. In April, 1927, a cat kept by a merchant in the central part of Kyoto City (Shimmachi Anegakoji-agaru) became missing. When she was found at home after a month, she was fretful, had no appetite and staggered, and crouched in a dark corner; three persons of the family who passed her were bitten on the 1 egs and hands; the wounds, which were not deep, were painted with iodine; the cat died under paralysis 3 days later. As there was an epidemic of rabies in Kyoto at that time and the preventive measure had been decreed by the police, the victims visited our laboratory; the vaccins were given to them immediately and the dead cat was sent to us at the same time, and the body was dissected; there were no marked changes with the naked eye anywhere, no foreign bodies in the stomach.
The brain of the cat was inoculated into the rabbits and the reaction was positive. The transmission experiments on rabbits and guinea pigs were carried out successively, and at about the 30th generation the strain was fixed at the 8th day. The strain has passed through 268 generations at present. It is necessary to test the immunizing effect of this virus for antirabies vaccine, as well as to conduct the histological studies with the brains of animals suffering from the disease uninfluenced by the cerebral trauma. We will be glad to send yon the virus at any time if requested. We are awaiting your criticism.

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This study was performed in order to examine the method of cultivating vaccinia virus, and to obtain the egg-adapted strain of vaccinia virus, and practically to evaluate the possibility of vaccine lymph production using the embryonated hen's egg.
1) When 5, 000 units of streptomycin and 500 units of penicillin G crystal were added into lml of vaccine lymph Tyrode suspension and then the mixture was inoculated into the allantoic fluid of chick embryo. As a result, it was found that the vaccinia virus could be propagated and all inoculated eggs were free from bacilli.
2) The distribution of vaccinia virus at the each portion of the egg was examined. It was the infectious chorioallantoic membrane to possess the highest infective unit. The embryo was the same or a little lower compared with the chorioallantoic membrane. The allantoic fluid possessed the low unit and the yolk lower. This distribution of vccinia virus in the egg was principally the same when the egg addapted strain of vaccinsa virus (20 passages) was inoculated.
3) The testicular strain of vaccinia virus pssessing the high infective unit (10^-7) was inoculated into the allantoic fluid of 12 day's embry and incubated at 37°C for 3-4 days. The infectious chorioallantoic membrane which was obtained consequently, was used as the next inoculum. In the same way, the infectious chorioallantoic membrane of inoculated egg was used as an inoculum of the next generation. In this way, the author has succeeded the successine cultivation of vaccinia virus for 23 generations and obtained the egg adapted strain possessing high infective unit (10^-15).
4) The culture method of influenza virus in the empty egg which was devised by Bernkopf (1950) was used at the cultivation of vaccinia virus. As a result, the favorable multiplication of the virus was found in it.

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It is known that the house rat (Rattus norvegicus) is not susceptible for Japanese B encephalitis (JBE) virus. The young rats weighing 60-70g were inoculated intracerebrally with an amount of 0.05cc of 10% brain suspension infected with the virus, strain No. 2869, which had been isolated from an encephalitis horse brain in Chiba 1947 and transferred mice to mice up to the 15th generation. The amount of virus in the rat brain was followed up daily by calculating LD 50 in each brain suspension. The virus was found gradually to decrease in titer by the 6th day while no more virus on the 3rd or the 4th days in the virus suspension preserved in the incubator of 37°C.
The virus was found 3 days longer in the brain of rats, injected with virus suspension mixed with autolyzed nornal rat brain suspension than in the brain injected with the virus suspension without autolyzed brain. However, there was no evidence that the autolyzed brain suspension enhanced the multiplication or promotion of the growth of virus in the brain.
Neither complement fixing antibody nor neutralizing antibodies were found in the sera cellected daily by the 30th day from the rats infected with single attack.

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