130 Shiro Tashiro 



Active Nerves. That the nerve increases its CO 2 production 

 approximately 2.5 times when stimulated, is in accordance with our 

 conception of the metabolism of other acting organs. Just how much 

 increase of CO 2 takes place during functional activity of an organ or 

 organisms depends on conditions as well as on habits of different organs 

 and animals. Pettenkofer and Voit 39 report that a man (weighing 

 70 kgs.) gives off when working 0.76 grams per kg. per hour, while 

 resting only .56 gram. Barcroft 40 found that the submaxillary gland 

 when stimulated by the chorda tympani gives off 3-7 times more 

 CO 2 than the resting gland. In the case of contracting muscle, the 

 results are very contradictory. Hermann 41 found that the contract- 

 ing muscle gave off 9.3 per cent of CO 2 (by volume) while the resting 

 one, only 1.4 per cent. Tissot 42 and other workers also found a 

 similar increase of CO 2 from contracting muscle. Minot, 43 working 

 with Ludwig, maintains that there is no relation whatever between 

 CO 2 production and muscle tetanus. L. Hill 44 and Fletcher 45 both con- 

 firmed Minot's work by finding no increase of CO 2 production from 

 muscular tetanus. According to Fletcher, the increase he found in 

 C0 2 production from a contracting muscle in a closed vessel is due to 

 the rigor. Under this condition, he believes, increased formation of 

 lactic acid is responsible for liberating CO 2 already produced. In 

 either case, it is understood that functional -activity in the muscle is 

 accompanied by an increase of metabolic activity. It is difficult to 

 compare this increase of metabolic activity of the muscle with that 

 of the nerve unless we determine how much and what ! ind of metabol- 

 ism takes place in contracting muscle. 



Respiration Quotient of the Nerve Fibre. As quoted before 

 Haberlandt found that a resting nerve consumes 41.7 to 83.4 cmm. 

 2 for i gm. for an hour at 19 - 24. Although he has not deter- 

 mined chemically the production of CO 2 he could easily read the 

 respiration quotient by means of the index fluid. Thus he found 



39 PETTENKOFER and VOIT: loc. cit. 



40 BARCROFT: Ergebnisse der Physiologic, 1908, vii, p. 735. 



41 HERMANN: Stoffwechsel der Muskeln, Hirschwald, Berlin, 1867. 



42 TISSOT: Archives de physiologic, 1894-5, (5) vii. p. 469. 



43 MINOT: Arbeiten aus der physiologischen Anstalt zu Leipzig, 1868, p. i. 



44 L. HILL: See Schafer's Text Book of Physiology, 1898, i, p. 911. 



45 FLETCHER: Journal of physiology, 1898-9, xxiii, p. 68. 



