Detailed electron microscopic study of cerebellum and medulla of sheepaffected with natural scrapie is reported. Two types of virus-like particles, non-membrane bound and membrane bound occur in neurons, pre-synaptic terminals and axis cylinders. The latter type were seen being apparently formed at the plasma membranes. Their size corresponds with that attributed to the scrapie agent. Three different types of tubules are described which filled a few axis cylinders and pre-synaptic terminals, their structure is compared with tubules found in other conditions.