628 JOHN R. MURLIN 



turely born, there is a plentiful amount of glycogen available at birth and 

 it is the requisition upon this reserve carbohydrate which produces the 

 high quotients. 



Hasselbalch infers much from the single experiment of Bohr on the 

 pregnant guinea pig (quoted at page 619) showing that the respiratory 

 quotient of the embryo is 1.0. It is quite possible that this is true, but 

 the single experiment of Bohr can hardly be accepted as proving the case 

 beyond doubt. Recent analyses of the blood of the mother and of the um- 

 bilical vein taken simultaneously at parturition show clearly that other 

 materials than glucose can pass the placenta very readily, and while one 

 may be prepared to believe that the main reliance of the embryo for energy 

 is the most diffusible of the foodstuffs, it must not be inferred that no 

 other substance is available for combustion in the fetus. Were carbo- 

 hydrate the only fuel available during antenatal life, it might be argued 

 that the enzymes are not yet ready for liberation of energy from fat (which 

 certainly is present), even if a large store of glycogen could not be demon- 

 strated ; and we might expect to find the quotients rather higher immedi- 

 ately after birth than a little later. Hasselbalch himself admits that the 

 facts are not quite so easily explained. Referring to Table 25 it is seen 

 that the highest quotients do not always come at the earliest hour. When 

 the same subject was used in two successive experiments, however, this 

 was found to be true. 



So convinced was Hasselbalch that the quotient was higher the bet- 

 ter the state of nutrition of the newborn that he thought he could tell 

 when the quotient was lower than 0.9 by signs of hunger in the infant. 



The occurrence of high quotients within the first seven or eight hours 

 after birth was observed independently also by Bailey and Murlin. They 

 drew attention to the particular interest which the quotient at this time 

 presents, as indicating the kind of material available for combustion as 

 the child breaks connection with the maternal circulation. They were 

 on their guard, however, against inferring, without further information 

 regarding the absorption of oxygen at this age, that the high quotient 

 necessarily proves a predominantly carbohydrate combustion. "Assum- 

 ing that oxygen absorption is normal at this age," they say, "the quo- 

 tients obtained would indicate the combustion of a considerable amount 

 of carbohydrate (glycogen)." Since Morris has published his sugar an- 

 alyses in maternal and umbilical bloods and has shown that the level of 

 the blood sugar is raised in both by a severe labor or by the use of an anes- 

 thetic, another explanation of the high quotients which are met with in the 

 early hours of postnatal life has been presented. Henceforth it will be 

 necessary to know something of the severity of labor and whether the 

 mother was given an anesthetic, before a plentiful supply of glycogen in 

 the liver of the newborn all ready for combustion the moment the cord is 

 tied, can be inferred. However, it is possible that the severe labor would 



