FEELING OF PAIN. 405 



superior aspect, and appears to be distinct from the grey substance over 

 which it passes : supposing therefore the longitudinal chain to consist 

 of anterior and posterior fasciculi, as in the medulla spinalis, we have 

 the anterior columns communicating with grey substance, while the 

 posterior are unconnected therewith, but are continued over the ganglion 

 instead of becoming amalgamated with its substance. Another fact 

 which favours Mr. Newport's view of the subject is derived from an 

 examination of the manner in which the nerves given off from the 

 central axis take their origin ; for some of them undoubtedly proceed 

 from the cineritious portion of the ganglionic swelling, while others, 

 derived from the upper column, not only have no connexion with the 

 grey matter, but arise at some distance from the ganglionic mass: 

 judging therefore by the laws at present established in physiology, there 

 seems reason to suppose that the anterior, or, rather, inferior fasciculi 

 are connected with sensation, while the superior constitute the motor 

 tract. 



(1034.) The reader who is conversant with human physiology will 

 at once perceive that this arrangement is precisely the reverse of that 

 met with in Man and other Vertebrata; and this consideration, appa- 

 rently of little importance, has given rise to a variety of curious specu- 

 lations some anatomists having even gone so far as to assert that all 

 the organs of articulated animals are in reality placed in a similar 

 inverted position. 



(1035.) A more interesting inquiry connected with this part of our 

 subject is, concerning the extent to which the AKTICTJLATA are suscept- 

 ible of pain. Is it really true in philosophy, as it has become a stand- 

 ing axiom in poetry, that 



" The poor beetle, that we tread upon, 

 In corporal sufferance feels a pang as great 

 As when a giant dies" ? 



(1036.) This is a question upon which modern discoveries in science 

 entitle us to offer an opinion; and the result of the investigation would 

 seem to afford more enlarged views relative to the beneficence displayed 

 in the construction of animals than the assertion of the poet would lead 

 us to anticipate. Pain, " Nature's kind harbinger of mischief," is only 

 inflicted for wise and important purposes either to give warning of the 

 existence of disease, or as a powerful stimulus prompting to escape from 

 danger. Acute perceptions of pain could scarcely, therefore, be sup- 

 posed to exist in animals deprived of all power of remedying the one 

 or of avoiding the other. In Man, the power of feeling pain indubitably 

 is placed exclusively in the brain; and if communication be cut off 

 between this organ and any part of the body, pain is no longer felt, 

 whatever mutilations may be inflicted. 



(1037.) The medulla spinalis, which, as we shall see hereafter, 

 corresponds to the ventral chain of ganglia in articulated animals, can 



