510 THE PHYSIOLOGY OF REPRODUCTION 



in them daily near the end of pregnancy. Hence the total daily 

 requirement for the unborn young at this stage is 1'662 grm. of 

 glycogen. A small additional amount of carbohydrate is re- 

 quired for the daily increasing blood-serum, for the liquor 

 amnii in the rabbit, and for the manufacture of mucin and 

 other glycoproteins. 



d. Excretion of Carbohydrates in Pregnancy : Glycosuria and 

 Lactosuria. Blot * was the first to postulate the occurrence 

 of a " physiological glycosuria " in pregnancy. Kirsten 2 

 found sugar in the urine in the majority of cases of pregnancy 

 and labour, and regularly in the puerperium. Hofmeister 3 

 first discussed the relationship of the glycosuria to milk secre- 

 tion, and proved that the sugar excreted in the puerperium 

 was lactose. 4 The sugar is in extremely small amounts, but 

 above the normal. Lemaire 5 found 0-003 to 0-009 per cent., 

 and Brocard 6 an upper limit of 0-01 per cent. Zacharjewsky, 7 

 however, observed no increase in the reducing power of the 

 urine on an ordinary diet during the last weeks of pregnancy. 

 The first definite increase conies with the appearance of lactose 

 in the urine after birth, though it may also be excreted a few 

 days before birth. It is more evident when the milk is not 

 utilised and becomes re-absorbed, but it rarely exceeds 0*3 per 

 cent. 8 Extirpation of the mammary glands immediately stops 

 the lactosuria, 9 and, if carried out in pregnancy, prevents it. 10 



1 Blot, "De la glycosurie physiologique chez les femmes en couches," 

 &c., Comp. Rend. Soc. Biol. t vol. xliii., 1856. 



2 Kirsten, " Ucber das Vorkommen von Zucker im Harn der Schwangeren," 

 Monatsschr. f. Geburtsh. u. Frauenkrankh., vol. ix., 1857. 



3 Hofmeister, " Ueber Laktosurie," Zeitschr. f. phys. Chem., vol. i., 1877. 



4 Corroborated by Kaltenbach (" Die Laktosurie der Wochnerinnen," 

 Zeitschr. f. Geburtsh. u. Gyndk., vol. iv.) and many others. 



5 Lemaire, " Ueber das Vorkommen von Milchzucker," Zeitschr. f. phys. 

 Chem., vol. xxi., 1895. 



6 Brocard, " La Glycosurie de la Grossesse," These de Paris, 1898. 



7 Zacharjewsky, loc. cit., Zeitschr. f. BioL, vol. xxx., 1894. 



8 The inability of the organism to oxidise lactose was demonstrated by 

 Voit (" Verhalten der Zuckerarten im menschlichen Organismus," Deut. Arch, 

 f. klin. Med., vol. Iviii., 1897). 



9 Sinety, " Urine of Guinea-Pigs in Puerperium," Comp. Rend. Soc. Biol., 

 vol. 1. 



10 V. Noorden, loc. cit., vol. i. (see also pp. 571-573). 



