OBSERVATIONS BY HASSELBALCH. 23 



more glycogen is stored), and the fact that the invertin 1 from the mucous 

 membrane of the small intestine provides the fetus with a ferment for 

 the eventual katabolism of this glycogen, are both arguments that 

 point towards the important role of the carbohydrate in the economy 

 of the fetus. Charrin and Guillemonat 2 find more glycogen in the liver 

 of the pregnant guinea-pig than in the non-pregnant; and this is true 

 both during inanition and during a rich carbohydrate feeding. In preg- 

 nant guinea-pigs this signifies, then, either an increased impulse towards 

 preparing glycogen from its food material or, in case of need, from its 

 own body elements. Furthermore, as already mentioned, Bohr has 

 definitely shown that the respiratory quotient of the guinea-pig's 

 embryo is 1.0, without reference to the fact that the respiratory quo- 

 tient of the mother may be lower. 



It may have been noticed that in most of the previous experiments 

 the percentage of carbon dioxide in the respiration chamber was quite 

 high, most frequently between 0.5 and 1.0 per cent. This was done in 

 order that the unavoidable errors in the analyses would have less effect 

 upon the results. That it is not this fairly high percentage of carbon 

 dioxide which has caused the difference between my results and those 

 of Scherer and Babdk is evident from the fact that these scientists have 

 worked with approximately the same percentage of carbon dioxide in 

 the respiration chamber. 



In the double experiments in table 2 the metabolism, i. e., the carbon 

 dioxide per kilogram and per hour, in the second half of the experiment 

 is in every instance considerably less than in the first half of the experi- 

 ment. This smaller metabolism, which was a result of the infant's 

 sleepiness in the later period, has no modifying influence on the size 

 of the quotient. The decreasing lung ventilation at the beginning of 

 sleep could well be thought in the first minutes 3 to be followed by a 

 slight drop in the quotient (if the relationship in this regard is the same 

 as in adults, which is not proved), but in the course of the 23 minutes 

 of the experiment in every case such an effect was soon compensated 

 for. The experimental period is after all so long that we can judge 

 of the nature of the oxidized material from the quotient without fearing 

 to be misled by the influence of lung ventilation or work. 



If we wish to be convinced that the quotients quoted above are 

 not affected systematically (and therefore are unaffected) by work done 

 during the experiment (crying, kicking, etc.) we need only to compare 

 experiments like 2 and 9 in table 1 on the one hand and 3 and 8 in table 

 1, and 5 in table 3, on the other. The comparison between 3 and 8 is 

 especially convincing; in 3 there is twice as great a metabolism as in 8, 

 due to the difference in muscular activity, but the same quotient is 

 found with both. 



That the percentage of carbon dioxide in the atmosphere about the 

 infant can not be considered to have an effect upon the quotient has 

 already been quite definitely settled for adults by Speck's 4 experiments. 

 In his experiments the same percentage of carbon dioxide as that used 



ra, Zeitschr. f. Biol., 1895, 32. 

 2 Charrin and Guillemonat, Compt. rend, de la soc. de biol., 1900. 

 3 Speck, Physiologic des menschlichen Athmens, Leipsic, 1892, p. 16. 4 Speck, loc. cit., p. 133. 



