In the spinal animal, in response to specific stimuli, various movements are elicited which though of a purposive character are effected, as has been so admirably worked out by Sherington, by complex spinal mechanisms of a reflex character. The so-called “scratch reflex” and the reflex movements of walking, trotting, and galloping (the animal being suspended in air) are examples. Such reflexes involve not only the excitation of certain movements appropriate to the stimulus but the inhibition of antagonistic muscles and reflex movements. Further in the integration of the spinal system, reflexes are compounded, one bringing to the support of another allied accessory reflexes so that various coöperative movements are executed. A constellation of reflexes leads to quite complex spinal mechanisms responsive to groups of stimuli acting concurrently and resulting in behavior which is purposive and adaptive to the situation. The neural processes executing such movements are necessarily conditioned by inherited dispositions and structural arrangements of the neurons. In the animal from which the cerebral hemispheres only have been removed there can be little doubt that the physiological mechanisms governing behavior differ only in complexity, not in kind, from those of the spinal reflexes; that in passing through successive anatomical levels from the spinal animal to this decerebrate animal with the addition of each successive ganglion the increasing complexity of behavior corresponds to increasing complexity of mechanisms or compounding of reflexes. And yet in the decerebrate animal without consciousness, as we must believe (excepting perhaps elementary sensations), the subcortical ganglia and spinal cord continue to perform exceedingly complex actions ordinarily, as we suppose, guided in the normal animal by consciousness. The reptile crawls; the fish swims; indeed the lancet fish has no brain, all its functions being regulated by its spinal cord. The frog hops and swims; the hen preens its feathers, walks and flies; the dog walks and runs. These, however, are the simplest examples of decerebrate behavior. Indeed it may be quite complex. The more recent experiments of Schräder on the pigeon and falcon and Goltz and Rothmann on the dog, not to mention those of earlier physiologists, have shown that the decerebrate unconscious (?) animal performs about all the movements performed by the normal animal.[123] “A mammal such as a rabbit, in the same way as a frog and a bird, may in the complete or all but complete absence of the cerebral hemispheres maintain a natural posture, free from all signs of disturbance of equilibrium, and is able to carry out with success at all events all the usual and common bodily movements. And as in the bird and frog, the evidence also shows that these movements not only may be started by, but in their carrying out are guided by and coordinated by, afferent impulses along afferent nerves, including those of the special