A HISTORY OF SCIENCE 



last assumed, and the stimuli, may be such as would 

 be attended by extreme or continued pain, if the sen- 

 sibility were undestroyed : in one case the animal re- 

 mained partially suspended over the acute edge of 

 the table ; in others the infliction of punctures and the 

 application of a lighted taper did not prevent the ani- 

 mal, still possessed of active powers of motion, from 

 passing into a state of complete and permanent quies- 

 cence." 



In summing up this long paper Hall concludes with 

 this sentence: "The reflex function appears in a word 

 to be the complement of the functions of the nervous 

 system hitherto known." 2 



All these considerations as to nerve currents and 

 nerve tracts becoming stock knowledge of science, it 

 was natural that interest should become stimulated as 

 to the exact character of these nerve tracts in them- 

 selves, and all the more natural in that the perfected 

 microscope was just now claiming all fields for its own. 

 A troop of observers soon entered upon the study of the 

 nerves, and the leader here, as in so many other lines 

 of microscopical research, was no other than Theodor 

 Schwann. Through his efforts, and with the invaluable 

 aid of such other workers as Remak, Purkinje, Henle, 

 Muller, and the rest, all the mystery as to the general 

 characteristics of nerve tracts was cleared away. It 

 came to be known that in its essentials a nerve tract is 

 a tenuous fibre or thread of protoplasm stretching be- 

 tween two terminal points in the organism, one of such 

 termini being usually a cell of the brain or spinal cord, 

 the other a distribution-point at or near the periphery 



258 



