For some years, we have been engaged in an investigation into the mode of action of toxins upon the central nervous system, and up to the present time have devoted our attention exclusively to the question of the upward passage of bacterial poisons along the sheaths of peripheral nerves to the spinal cord and brain. Experiment has shown us that toxins readily travel upwards in the perineural lymphatics, in which they induce an inflammation whose phenomena vary with the intensity of the irritant; and that this is continued without interruption to the central nervous system, granted that the toxins gain that level. Continuity of extension is, therefore, an important feature of lymphogenous inflammation, and is as constant in the central as in the peripheral nervous system.