We have seen that the main stress of the toxemia of lethargic encephalitis falls on the nerve cells. At certain sites the toxic action is reinforced by the direct attack of the infectious agents (Loewy-Strauss bodies?) on the nerve cells. The nerve sites attacked by these organisms are determined in part by the particular mucous membrane in which the initial invasion takes place. From this area, the organisms are carried along the lymphatics to the central nervous system. As the habitually invaded area is the nasopharyngeal mucosa, the nerve sites usually attacked are in the head end of the nerve axis; but if the intestinal mucosa be the invaded area, the brunt of the attack falls on the caudal end of the nerve axis. The direction, extent and severity of the attack on the nervous system determine the nature and degree of the resulting functional disturbances. It has already been