METABOLISM IN THE MUSCLES. 591 



On the other side, BOHM has observed cases in which no consumption 

 of glycogen took place in rigor of the muscle, and he also found that the 

 quantity of lactic acid produced is not proportional to the quantity of 

 glycogen. According to MOSCATI l the diminution in the glycogen is 

 independent of the appearance of rigor. It is therefore possible that the 

 consumption of glycogen and the formation of lactic acid in the muscles 

 are two processes independent of each other, and, as above stated in regard 

 to the formation of paralactic acid, the origin of the lactic acid in the 

 muscle is still not positively known. The phosphocarnic acid must 

 also be considered as a mother-substance of the lactic acid, and of the 

 carbon dioxide, also formed in the rigor, as it yields lactic acid as well as 

 carbon dioxide on its cleavage. 



Metabolism in the Inactive and Active Muscles. It is admitted 

 by a number of prominent investigators, PFLUGER and COLASANTI, 

 ZUNTZ and RoHRiG 2 , and others, that the metabolism in the muscles 

 is regulated by the nervous system. When at rest, when there is no 

 mechanical exertion, there exists a condition which ZUNTZ and ROHRIG 

 have designated " chemical tonus." This tonus seems to be a reflex 

 tonus, for it may be reduced by discontinuing the connection between the 

 muscles and the central organ of the nervous system by cutting through 

 the spinal cord or the muscle-nerves. The possibility of reducing the 

 chemical tonus of the muscles in various ways offers an important means 

 of deciding the extent and kind of chemical processes going on in the 

 muscles when at rest. In comparative chemical investigation of the 

 processes in the active and the inactive muscles several methods of pro- 

 cedure have been adopted. The same active and inactive muscles have 

 been compared after removal, also the arterial and venous muscle-blood 

 in rest and activity, and lastly the total exchange of material, the receipts 

 and expenditures of the organism, have been investigated under these 

 two conditions. 



By investigations according to these several methods it was found 

 that the resting muscle takes up oxygen from the blood and returns to 

 it carbon dioxide, and also that the quantity of oxygen taken up is greater 

 than the oxygen contained in the carbon dioxide eliminated at the same 

 time. The muscle, therefore, holds in some form of combination a part 

 of the oxygen taken up while at rest. During activity the exchange of 

 material in the muscle, and therewith the exchange of gas, is increased. 



'Nasse, Beitr. z. Physiol. der kontrakt. Substanz, Pfluger's Arch., 2; Werther, 

 ibid., 46; Bohm, ibid., 23 and 46; Moscati, Hofmeister's Beitrage, 10. 



2 See the works of Pfliiger and his pupils in Pfluger's Arch., 4, 12, 14, 16, and 18; 

 Rohrig, ibid., 4. See also Zuntz, ibid., 12. In regard to the metabolism after curare 

 poisoning, see also Frank and Voit, Zeitschr. f. Biologic, 42, and Frank and Geb- 

 hard, ibid., 43. 



