CHARACTER OF THE KATABOLISM. 93 



the carbon-dioxide production and the respiratory quotient is shown in 

 observations Nos. 13-14 and 19-20. 



It will be remembered that in our consideration of the values in table 

 10 (see page 81), a like increase in the metabolism was found to accom- 

 pany the abnormal increase in the respiratory quotient and that the 

 conclusion was drawn that this increase was in part due to the muscular 

 activity of the infant, and specifically to the excess carbon-dioxide 

 produced in crying. The notes accompanying Hasselbalch's protocols 

 specify that the infant was not crying ; nevertheless we know too little at 

 present regarding the ventilation of the lungs of new-born infants not to 

 assume that there may certainly have been a distinctly excessive ventila- 

 tion, with an accompanying increase in the carbon-dioxide excretion. 

 We have here, then, an actual increase in the katabolism of considerable 

 magnitude, with the high probability of there being somewhat more car- 

 bon dioxide produced than oxygen consumed, the difference being suffi- 

 cient to cause a corresponding variation in the respiratory quotient. 



The fact that in a large number of our observations of long duration 

 these abnormally high quotients appear not only in the first hours, but, 

 later, lends considerable strength to this supposition. We are inclined 

 to believe, therefore, that Hasselbalch's conclusion that the higher 

 respiratory quotients are obtained in those observations which are 

 nearest to the birth is due not to the larger proportion of the glycogen 

 taking part in the combustion, but to an increase in the carbon-dioxide 

 excretion, owing to a disturbance in the mechanics of respiration. 



On the first day of life there is a gradual decrease in the respiratory 

 quotient which is fully comparable to that experienced with any fasting 

 organism in which the initial supply of glycogen is fairly liberal. On 

 the other hand, the quotients found shortly after birth and the level 

 to which they fall on the first day are not such as to justify the conclu- 

 sion that there is an excessive glycogen storage in the body of the new- 

 born infant. On the second and subsequent days the respiratory 

 quotients decrease, indicating a somewhat rapid depletion of glycogen 

 until the quotient of 0.73 is reached, this being similar to the metabo- 

 lism of fasting animals. When the milk-flow is fully established, and 

 the body is in consequence supplied more liberally with carbohydrate 

 material, the average respiratory quotient increases until at the end 

 of the first week it is 0.81. 



No obvious relationship between the respiratory quotient and the 

 size and condition of nourishment can be found from the data obtained. 

 As information is lacking in regard to the degree of nourishment of the 

 mothers, no study can be made of the relationship between the respira- 

 tory quotient and this factor. 



