Abstract
The possibility of selective spread through pyramidal tract of polio virus was studied with mice inoculated intracerebrally with Lansing strain. The inoculation was made mainly into the right cerebral hemisphere.
Results obtained indicated that the number of mice showing paralysis only right leg (identical side for the inoculation) was about equal to that showing paralysis only on the left leg (opposite side for the inoculation) either in the group inoculated with virus of 3000×LD50 or 30×LD50.
No coclusive evidence, therefore, was obtained as to the reality of the “pyramidal tract spread” theory of polio virus.
