1. Inoculation of suspensions of brain, cord, ganglia or nerves of chickens with neurolymphomatous lesions, into newly hatched chicks, is followed by the development of typical lesions in approximately 25 per cent of cases. 2. In control chickens kept under laboratory conditions the incidence of the disease is about 7 per cent. 3. The disease does not become manifest until at least 2 months after inoculation; symptoms may not appear until after 4 months. 4. The active agent is not destroyed by 50 per cent glycerol in 9 days at ice box temperature.