THE NERVOUS SYSTEM AND CONSCIOUSNESS. 743 



spinal cord to the blood-vessels through the ganglia and fibers of the 

 sympathetic system. These nerves, being constantly active, maintain 

 a tonic contraction of the arterial walls. 



The medulla is a center for the movements of chewing and swal- 

 lowing. This center can be excited in a reflex manner, and by the 

 will, but not automatically. There seems to be good evidence that the 

 medulla is a center for combined or co-ordinated movements of the 

 body. Wundt is of opinion that the collective motor-fibers of the 

 body are brought into closer union with each other in this organ. His 

 opinion rests upon the fact that, as long as the medulla is intact, sen- 

 sible excitations occasion general movements of the body much more 

 easily than when this organ is destroyed. 



The question now arises as to the relation between the medulla and 

 consciousness. I do not think we are justified in supposing that con- 

 sciousness appears in connection 

 with this portion of the nervous 

 system. It is a fact that a frog, 

 having simply the cord and medulla, 

 will react not only in the manner 

 already described, but also by move- 

 ments of the entire body, away from 

 the source of trouble ; the animal 

 may even utter a cry as if in pain, 

 yet he may be " merely a non-sen- 

 tient, non-intelligent reflex mechan- 



„ ___ , , , in Fig 10. — Thalami AND Striata. (Sappey. after 



ISm. We know that the medulla Hirschleld.) is, posterior tubercles of the 



.^ ^ , .• e J.1 thalami ; 19, auterior tubercles of same ; 21, 



IS tiie last portion OI the nervous veins of the corpus etriatum; ^3, corpus 



system to come under the influence ^ ^^^ "™' 



of anaesthetics. Persons submitting to severe surgical operations fre- 

 quently cry out violently, and as if in intense pain ; yet they assure us 

 afterward that they were not conscious of suffering. 



It is common to cite, as Dr. Hammond has done in the article before 

 mentioned, those human beings who are born without a cerebellum or 

 cerebrum, but who perform such actions as breathing, sucking, swal- 

 lowing, and crying. In these cases the spinal cord and medulla oblon- 

 gata are well developed. Why consciousness should be ascribed to 

 the activities just named it seems difiicult to understand, especially 

 when we consider that similar activities can be produced by a machine 

 constructed for the purpose. To say that, " if these activities are not 

 indicative of the existence of mind, we must deny this force to all hu- 

 man beings on their entrance into the world," is a singular declaration 

 — what would be the harm of such denial ? 



Most human beings on their entrance into the world have the higher 

 cerebral centers, yet they are so soft and undeveloped as to make it 

 doubtful whether consciousness even then appears ; certainly it does 

 not except in most elementary form. We have now to inquire respect- 



