8 PHYSIOLOGY OF THE NEW-BORN INFANT. 



studies and chemical analyses do not necessarily agree. 1 It is gener- 

 ally considered, however, that the fetus has a larger supply of glycogen 

 in proportion to its weight than has the mother. If, as we believe, 

 the character of the combustion is determined in large measure by the 

 character of the available food-supply, it is not inconceivable that there 

 may be a larger combustion of glycogen and a specific fetal katabolism. 

 On the other hand, the oxygen and food are obtained from the blood of 

 the mother, and while the fetus may be glycogen-rich, the liver of the 

 mother is likewise glycogen-rich, and hence it may be unreasonable to 

 expect a specific gaseous metabolism of the embryo in the pre-natal state. 

 It is hardly probable that with our present technique we can ration- 

 ally interpret the character of the katabolism of the fetus by measuring 

 the gaseous metabolism of the mother and the child before the birth of 

 the child, and the mother alone after delivery, for as the metabolism 

 of the mother is very much greater than that of the child, a differential 

 method is liable to very great error. 



POST-NATAL CONDITIONS. 



As soon as the child is born all of the conditions are changed. Prior 

 to birth the fetus is living on a rich f ood-supply which is brought by the 

 maternal blood. Immediately after birth this supply is cut off and no 

 food is thus derived from the mother. The infant then begins to 

 starve, that is, to draw upon its reserve body-material until the mother's 

 breasts secrete enough food to supply its demands. We may properly 

 ask, what is this reserve and how does it influence the character as 

 well as the totality of the katabolism? The amount of the material 

 burned we know is determined in large part by the muscular activity 

 of the infant, but since now the infant must live (for the first hours, at 

 least) solely upon its own body-reserve, the character of the material 

 available for combustion and the character of the material actually 

 burned present a new interest. 



No mammal mother is so completely incapacitated for carrying out 

 the duties necessary to protect and nourish her young during the first 

 few days after parturition as is civilized woman. On the first day after 

 birth, the mother is usually absolutely dependent upon the ministra- 

 tions of others. The infant must likewise share this dependency upon 

 others. Even the natural food-supply of the parturient mother is extra- 

 ordinarily small, for the total fuel value of the colostrum is insufficient 

 during the first few days, even under the most favorable circumstances. 2 



We may question, then, is the new-born child automatically adjusted 

 to this state of affairs? Is the body-supply sufficiently liberal to pro- 

 vide for the draft upon it, and have we really, therefore, a self-contained 

 little engine? What are the infant's needs for the first few days? 



'Rusk, Proc. Soc. Exp. Biol. and Med.. 1912, 10, p. 21. 

 2 See page 122. 



