The motility of higher mammals can be divided into two large groups of different movements. One of them is cortical in origin and deals with the finer adjustment of isolated movements to visual, acoustic and tactile stimuli. The efferent impulses for these movements leave the brain largely from the area gigantopyramidalis. The other group, called principal motility by von Monakow, consists of coarse responses to sensory stimuli, namely, all those innervations which are necessary for standing and locomotion and for the motor part of alimentation. The investigations of Freusberg,1 Sherrington,2 and Magnus3 have shown that even the isolated spinal cord gives certain rather complicated responses to pain and to cutaneous and proprioceptive stimuli. If not only the spinal cord but also the centers of the lower part of the brain stem are left intact, then a general integration of tonic innervations for the whole body appears, which