About a year ago1 Dr. A. Negri of the University of Pavia described certain bodies which he had observed in the nervous system of animals dead of hydrophobia. These bodies are found in the protoplasm of nerve cells and occasionally in the processes, but not in the nucleus, though they may be in contact with it. Their distribution in various parts of the nervous system is fairly constant. They are usually found in greatest abundance and are also, as a rule, larger in the hippocampus major, but also appear frequently in the Purkinje cells in the cerebellum, in the pyramidal cells of the cerebral cortex, and often in the pons, the spinal ganglia, the gasserian ganglia and in the spinal cord.
The bodies are round or oval in shape or may be oblong and somewhat irregular. They vary a great deal in size, depending on their location in the