1243 



which I reproduced here. The forms of muscle-shortening indicated in these, perhaps 

 or even probably arise from stimulation of the muscle-substance itself, so they have 

 a muscular origin, in which the nervous system does not play any part. I left out 

 the columns on the two types of tonus after Lanoelaan, because his division does 

 not agree in my opinion, with several physiological facts. (See the criticism in my 

 communication on muscletonus in Pfluger's Aichiv, Bd. 166, p. 163—165). I put 

 the? io the second column of my table referring to the initial hypotonus in the 

 acute experiment (Dusser de Barenne— von Brücke). 



Althoiigl) it has appeared that none of tl)e views uttered b}' 

 DK BoEH in this question is right, I have still tried in some olher 

 experiments to obtain proofs in favour of the supposed conneclion 

 between muscle (onus and sympathetic innervation. My reasoning 

 was the following: Supposing that the sympathetic nervous system 

 has something to do with the mechanical muscle tonus, with the 

 inward support of the muscles, then we might ex|)ect that some 

 proof of this will appear in (he musdecurves of fatigue or in 

 curves illustrating the origin of tetanus by stimulation of increasing 

 frequency. The result of these experiments was however quite a 

 negative one, i.e. neither in the acute experiment, nor in the 

 chronic one with degenerated sympathetic endplates, was there 

 any essential ditference in the muscle cuives of the 2 gastrocnemii, 

 of which one was deprived of its sympalhelic innervation. 



In the acute experiments the two largest ventral roots of the 

 Nn. ischiadici were put on the electrodes, to stimulate the nerves 

 centrally of the sympathetic chain aiming to avoid the post ganglionic 

 neurones from being stimulated. In the chronic experiments the Nn. 

 ischiadici were stimulated in the abdomen. 



Small differences between the 2 curves of fatigue were perceptible, 

 but these did not point in all cases in the same direction. In some 

 cases the "Verkürzungsrückstand" in the muscles deprived of their 

 sympathetic innervation was less evident than in the normal gastroc- 

 nemius. In other cases just the opposite took place. Besides, curves, 

 taken as a test, of the 2 gastrocnemii of normal frogs, often showed 

 similar small differences. It is noteworthy that all precautions were 

 taken in these experiments to obtain a great regularity and equal 

 intensity of the stimulations. I used therefore an induction apparatus 

 with the usual waterwashed mercury contacts after Kroneckeh. A 

 very considerable resistance was interpolated in the secondary 

 circuit (120.000—150.000 Ohm). The stimulations were given by 

 a metronome. Thanks to all these prcautions the curves generally 

 showed a beautiful regularity. The stimulations were always either 

 make — or break — induction shocks; the impulses of contrary direction 

 were eliminated by the well-known method of Pflüger. 



