Such control or predominance is manifested in the following ways: First. The functions of animal life, presided over by the cerebro-spinal system, become proportionately more important than those of vegetative or nutritive life, carried on by the ganglionic. That is to say, the acts of locomotion sustained by the spinal cord and the nervo-muscular apparatus, and the intellectual acts of the thought and will, sustained by the brain--are relatively more prominent than are the acts of digestion, respiration, circulation, etc., dependent on the functions of the ganglionic nerves. Second. These latter functions are themselves effected with more regularity and more force, when the activity of the cerebro-spinal system predominates over that of the ganglionic. Within certain limits, this is so true, that human beings possess over lower animals a superiority, not only of intellect, but of capacity for digesting various articles of food; and of maintaining their temperature in more various states of the external atmosphere. Third. Finally, the actions of the cerebro-spinal system, intellectual and muscular, are more regular and powerful when not liable to interruption from the operations of the ganglionic nerves, and the visceral functions presided over by them. When the boa-constrictor digests, he falls into a state of torpor that exceeds in degree, but not in kind, the drowsy rumination of a cow chewing her cud. Such animals are slaves to their nutritive functions, by which those of the brain and spinal cord may at any time be, as it were, oppressed and overwhelmed. The capacity for independence increases with every rise in the hierarchical scale of vertebrates, until it culminates in man--able to think and talk over his dinner; to manufacture heat in his limbs while drawing blood to his cerebral hemispheres; to sustain in complete unconsciousness innumerable delicate and complicated chemical metamorphoses in all the tissues of his body, while concentrating every conscious effort of his mind upon equally delicate processes of thought and will.