CHANGES IN THE MATERNAL ORGANISM 509 



glycogen an available supply is procured in every part of the 

 foetal body in which the work of organisation is proceeding. 



c. The Daily Requirement of Carbohydrate for the Foetus. — 

 Some idea can be obtained of the daily requirements of glycogen 

 for the foetus of the rabbit in the second half of pregnancy. 

 The appended table gives the amount of glycogen contained in 

 the unborn young from the eighteenth day of gestation till the 

 day before parturition : — 



Table to show the fcetal ' weight and amount of foetal glycogen 

 in the second, half of pregnancy (rabbit). In the animal killed at 

 the twenty-sixth day, the pregnancy was abnormal, one foetus being 

 dead and the others badly developed. In the last also the foetuses 

 were unusually small. 



The table shows that 1^2 grm. of glycogen are deposited 

 between the eighteenth and the twenty-eighth day, or about 0-2 

 grm. per foetus. Hence the average daily deposition is 0-02 grm. 

 per foetus. In the later stages the rate of deposition increases 

 out of proportion. This is due to the assumption of its glycogenic 

 function by the foetal hver. 



The amount of carbohydrate oxidised each day can be 

 calculated from Bohr's figures. The oxygen consumption for a 

 foetus weighing 30 grm. is 0-14 c.cm. per minute. This is sufficient 

 to oxidise 0-00017 grm. of sugar, or 0-245 grm. per day, which is 

 equal to 0-227 grm. of glycogen. Hence for six foetuses, the 

 average number, 1-362 grm. are required for combustion each 

 day. In addition, an average of 0-3 grm. of glycogen is deposited 



