THE SPINAL BRAIN. 31 



the latter supplies. For example, a pinch applied to the leg lodges 

 its complaint at the gray centre, which at once by its nerves sets the 

 muscles and the limb in that motion which enables the part to escape 

 the distress. This is now termed, reflex action, which means that 

 an impression is communicated to a nervous centre by a set of quasi- 

 sentient nerves, and a motion reflected from that centre by a set 

 of motor nerves. It does not necessarily involve consciousness. A 

 paralytic man, with no feeling in his legs, if the soles of his feet be 

 tickled will move them away from the irritation, just as though he 

 perceived it. In short, the spinal brain is unconscious, or let us 

 rather say, we are unconscious of its feelings. We term its nerves 

 therefore, not sentient, but quasi-sentient. 



We come now to a second and distinct piece of nervous system, of 

 whose operations we may still be unconscious, viz., the medulla ob- 

 longata, whose nerves are connected with the organs of respiration 

 and the ingestion of food — with the functions of breathing and of 

 eating, which although they may be permeated by sensation, and 

 controlled by the will, may also occur independently of either; as 

 during sleep, when breathing still proceeds, and in various cases 

 when the movements of eating and deglutition are performed without 

 cognizance. All that is necessary for continuing the actions of the 

 parts of the body supplied from these centres, is, that a quasi-sensa- 

 tion be communicated to them, which the centres act upon through 

 the motor apparatus of nerves. The conception of so mere a ma- 

 chine in man, is perhaps difficult to realize ; the spinal brain, how- 

 ever, with its dependencies, represents an automaton man as the 

 basement of the nervous system. It is the organization of routine 

 or insect progress. By it we walk, work and eat when we are not 

 thinking of those operations; and thus the inherent properties of this 

 routine system save us from much expenditure of attention, and allow 

 the brain and the senses to be emancipated as necessity requires from 

 the lowest wants. Had we to perform our animal functions by direct 

 volitions, we should have no time for anything better : if each breath 

 were a distinct voluntary act, breathing alone would fill our lives : 

 nor in this case would walking or an} 7 other external function be 

 possible, for the will does but one thing at once. As it is, however, 

 a number of bodily acts are momentaneously and harmonically per- 



