WALTER HOLBROOK GASKELL LANGLEY. 527 



the working of the several parts. Thus, those writers who tried to 

 give an impartial summary of the state of knowledge found them- 

 selves reduced to stating a number of more or less contradictory- 

 facts and irreconcilable theories. 



Gaskell did not approach the subject from the point of view of 

 what had already been done or said. He approached it from the 

 point of view suggested by his observations on the accelerator nerves 

 in the mammal. This method had the disadvantage that it led 

 him to leave uninvestigated some of the chief difficulties which were 

 felt at the time, but it had the advantage that it enabled him to 

 come to a rapid decision on certain important points. Gaskell con- 

 fined his attention to the efferent " visceral " fibers. His most im- 

 portant conclusions were, that all efferent visceral fibers, Avhether 

 in cranial or in spinal nerves, were small medullated fibers, and that 

 they left the cerebrospinal system in three groups — the cervico- 

 cranial, the thoracic, and the sacral — the thoracic portion being what 

 was ordinarily called the sympathetic. These conclusions reestab- 

 lished the connection of small medullated fibers with the whole of the 

 "organic" system described by Bidder and Volkmann in 1842, gave 

 an explanation of Reissner's statement in 1862 that the anterior roots 

 of the thoracic nerves contained bundles of small medullated fibers, 

 while those of the cervical and lumbar nerves contained only a few 

 such fibers scattered amongst the larger ones, supported the view 

 which had been held by some anatomists that the white rami com- 

 municantes constituted the sole connection between the spinal cord 

 and the sympathetic, and brought all the involuntary nerves of what- 

 ever origin into one system of gaglionated nerves as had been recently 

 {•dvocated b}^ Dastre and Morat. In these conclusions there was one 

 weak spot. Whilst it was definitely shown that the outflow of visceral 

 fibers from the central nervous sj^stem to the sympathetic was enor- 

 mously greater in the regions in which there were only white rami, it 

 was not shown that no fibers passed out by the gray rami. Gaskell's 

 observation of the rarity of small medullated fibers in the gray rami 

 was not in accord with earlier observations, and he did in fact under- 

 estimate their number. Further, physiologists of repute had de- 

 scribed vasomotor, pupil or heart effects as being caused by stimula- 

 tion of the cervical nerves, which had gray rami only. It might then 

 be said that the few small medullated fibers present in the centrally 

 running branch of the gray rami represented the few scattered small 

 medullated fibers of the anterior roots of the corresponding spinal 

 nerves. Thus the difference between the thoracic and other regions 

 of the spinal cord might be one of degree only. So far, however, as 

 subsequent investigation has gone, Gaskell's conclusion was correct, 

 and the gray rami receive no efferent fibers from the spinal cord. 



