The conditions existing in rabies support my contention of the lymphatic spread of infantile paralysis. I proved that the changes in both diseases were completely in harmony; and that, from a pathological aspect, each had an equal right to be called an acute poliomyelitis. In rabies the spread of the virus was proved to occur by way of the nerves. But Homen, by his studies, has since shown that the way of the nerves is the path of their lymphatics.
Experimental investigations in monkeys have now practically confirmed the hypothesis of the lymphatic spread of acute poliomyelitis. It has already been mentioned that the disease can be produced by intravascular, subcutaneous, subdural, intracerebral, intraneural and intestinal inoculation. These various procedures, however, are of unequal value. The most reliable are intracerebral and intraneural inoculation.
How does the poison reach the spinal cord from an inoculation not infecting the blood? Most of the workers upon experimental poliomyelitis in monkeys have come to the conclusion that the virus spreads from the site of inoculation especially by way of the nerves; the infection extends along the lymphatics, which accompany the nerves. I can hardly do better than quote Leiner and v. Wiesner, who have directed special attention to this question: "In the vast majority of our experiments—omitting for the moment those which were intracerebral—we observed a definite relation between the site of the inoculation and the seat of the paralysis, analogous to that already established in inoculation experiments with tetanus. Flexner and Lewis, Levaditi and Landsteiner, and we, have already demonstrated that the inoculated extremity is the first to become affected with the disease. In proceeding with further experiments, we almost invariably proved that an inoculation in a nerve of a posterior extremity produced paralysis which was situated in, and tended to remain restricted to, the hind end of the body; and similarly, an inoculation in the median nerve primarily affected the fore part. Infection through the digestive tract causes paralysis of the posterior, that through the respiratory tract, of the anterior half of the body." These investigators conclude: "Our results, as a whole, indicate clearly that the seat of the paralysis depends upon the site of the inoculation; and that the virus of poliomyelitis reaches the spinal cord by the shortest route. We are thus able to con-
