J 245 



considerably he lessened hy too small an exchange of blood within 

 these innscles. This factoi' eventually might have lowered the total 

 gasexchange of their animals, as has been shown by their experiments. 

 Whether this objection has any ground cannot be made out 

 without experiment, but it proves anyhow, that the experiments by 

 Mansfeld and LuKacs are as yet not indisputable. 



Until now we always accepted as a fact in all the experiments 

 and specidations communicated, that the sympathetic nei'vefibres of 

 BoKKE ai'e centrifugal sympathetic nervelibres, a supposition for 

 which several very evident histological aj-guments might be cited, 

 but which has not been proved, as I said already once more. 



This has been proved lately by a research ad hoc by Prof. Boekk 

 and me and besides by some similar experiments, made indepen- 

 dently of us by Agduhr. 



If those nervefibres of Bokke were indeed centrifugal sympathetic 

 nei-vefibres, then it ought to be possible to preserve these in "pure 

 cullui'e" in the sti-iped muscles, by section of the ventral nerve roots 

 leading to one or more muscles, and extirpation of the correspond- 

 ing spinal ganglia. After this section all the cerebrospinal motor 

 nervetibres with their so-called endplates of Kijhne together with all 

 the sensoiT fibres and organs in the muscles concerned ought to 

 degenerate. 



Granting that Boekk's fibres are centrifugal symjtathetic nervetibres, 

 whose praeganglionic neurones have their origin in the spinal coi'd, 

 leave the cord with the ventral root and terminate round the cells 

 of the post-ganglion ic neurones in the ganglia of the sympathetic 

 chain those fibres of Boekr ought to remain unaltered in a similar 

 experiment. A look on the following scheme illustrates the concep- 

 tion on which these experiments are based. (Fig. 4). 



The intercostal muscles of dog and cat have served as object for 

 this experimental histological investigation, because the metameric 

 arrangement has been best preserved in these muscles. There is no 

 fear here for confusion caused by the plurisegmeutal innervation. 

 The result of these experiments has been, that the nervefibres and endpla- 

 tes of BoEKK remained intact in the muscles between the ribs. All the 

 niotor cerebro-spinal nervefibres and endplates, as well as the sensory 

 muscle-organs had disappeared. 



Numberless amyelinic axiscylinders were preserved in the peripheral 

 nerves (intercostal nerves) and beautiful accessory nervefibres and end- 

 plates of Boekk in the muscles. By this result it has been proved that 

 these nervefibres ai-o indeed ceidrifugai sympathetic nervous systems. 



