538 THE PHYSIOLOGY OF REPRODUCTION 



in the human female (Charrin and (iviillemont J ). But since the 

 amount of glycogen varies greatly and is dependent to a large extent 

 on the diet, it is difficult to establish with certainty that there 

 is an increase. Harding, 2 on the other hand, postulates a greater 

 tendency to a deficiency of glycogen in the maternal liver and 

 associates this deficiency with the morning sickness of women and 

 even with pernicious vomiting. This view is based on the work of 

 Bohr and of Lochhead and Cramer, 3 who showed that the presence 

 of the fcetal cells imposes a special demand for carbohydrates on the 

 maternal organism. The pregnant woman has therefore a greater 

 tendency to pass into a state of specific carbohydrate starvation 

 than the non-pregnant woman. The important practical application 

 of this fact will be discussed in greater detail below (see p. 544). 



The placenta contains glycogen in amounts which vary greatly in 

 different sj>ecies. 3 It is found only in traces in lluminants, hut 

 in great amount in Rodents (see Chapter X., p. 460). It occurs 

 also at the margin of the xonary placenta in Carnivores, and in the 

 human placenta. In many species it has not yet l>een investigated. 



In the fetus, the feature of the glycogen is not its high 

 percentage, but its almost universal distribution in the developing 

 tissues. 4 It has been shown by Bohr that the energy in the 

 mammalian t'o'tus is supplied by the combustion of carbohydrates 

 (see p. 553), and by the wide distribution of glycogen an available 

 supply is procured in every part of the foetal l>ody in which the work 

 of organisation is proceeding. 



c. ) Tin- Dully Ifrtjiiii-i-iiK'nt <>f Carbohydrate for the F<i-tux. Some 

 idea can le obtained of the daily requirements of glycogen for the 

 fcptus of the rabbit in the second half of pregnancy. The appended 

 table, from the paper of Lochhead and Cramer, 5 gives the amount of 

 glycogen contained in the unborn young from the eighteenth day 

 of gestation till the day l>efore parturition. 



The table shows that l"2 gm. of glycogen are deposited between 

 the eighteenth and the twenty-eighth day, or about 0'2 gm. per fo-tus. 

 Hence the average daily deposition is 0'02 gm. per foetus. In the later 

 ^tages the rate of deposition increases out of proportion. This is due 

 to tin- assumption of its glycogenic function by the fo?tal liver. 



1 Chan-in ami ( Jnillemont, "Physiologic pathologique de la < in^ses-,.-." 

 < ',/*. //>//. ,W. /;//., 1899. 



Harding, "Nausea and Vomiting in Pregnancy." Tl,<- L>nn->-t, vol. ccl., \it-2\. 

 !.< hhead and Cramer, "The Glycogenic Changes in the Placenta and the 

 Fu-tus of the Pregnant Rabbit," Pfoc. ]!,/. S,,.-. London, B., vol. Ixxx., 19O8. 



4 Gierke, "Glycogen in der Morphologic des Zellstoftwechsels," H(il>H !/"/!<>.<- 

 thrift, Freiburg, 1905. 



L< hhead and Cramer, "The Glycogenic Changes in the Placenta and the 

 fatal of the Pregnant Rabbit. Proe. /!>?. S,,,-. h,,,,!,-,,., Ser. B., vol. Ixxx., 1908. 



