THE SOURCE OF THE AMNIOTIC AND ALLANTOIC FLUIDS IN MAMMALS. 



95 



{Reports from the Laboratory of the Royal College of Physicians of Edinburgh, 

 vol. viii., 1903) found glycogen absent from the foetal rabbit on the 22nd day, but 

 present in the placenta from the 8th day. 



The demonstration of the origin of the Isevulose from the foetus and of its presence 

 in such considerable quantities in the foetal urine is further proof that the foetal fluids 

 are derived from the foetal kidneys. 



The presence of Isevulose as a normal constituent of the blood and urine of the foetus 

 is of considerable interest in connection with the occurrence of cases of lsevulosuria in 

 man without any apparent cause. 



The relationship of the sugar to the non-protein nitrogen throughout pregnancy is 

 of interest. While in the amniotic fluid the sugar is increased threefold and the 

 nitrogen undergoes a much smaller increase, in the allantoic fluid the nitrogen is 

 increased more than threefold, while the sugar undergoes only a slight rise. 



The proportion between nitrogen and sugar thus varies as is shown in Tables M 

 and N. 



TABLE N. 

 Relationship of Sugar to Non-Protein Nitrogen at Different Stages of Pregnancy. 



Weight of Foetus, 

 grms. 



G 



N" 



Amniotic. 



Allantoic. 



Below 15 . 

 30 to 100 . 

 100 to 300 

 300 to 1670 . 



2 



2-4 

 3-8 

 5-7 



5-6 

 3-4 



2-05 



(/) Salts. — The salts of the foetal fluids in the cow throughout pregnancy have been 

 investigated by Doderlein (loc. cit., p. 161 et seq.). He finds the chlorides are higher in 

 amount in the amniotic than in the allantoic fluid, and that in both fluids the percentage 

 varies little throughout pregnancy. The average, as NaCl, is in the amniotic fluid 

 0*59 per cent., and in the allantoic 0"23. The sodium behaves like the chlorine. 

 Potassium remains constant at about 0*05 per cent, in the amniotic fluid, but in the 

 allantoic fluid it increases from - 03 to 0*1 3. He finds a very marked difference in 

 the percentage of magnesium in the two fluids, it being almost absent from the 

 amniotic, but present in the allantoic to the extent of 0'01 to 0*05 per cent. 



Our analyses give the following results. The methods used are given in the 

 Appendix. 



TRANS. ROY. SOC. EDIN., VOL. XLVI. PART I. (NO. 3). 



14 



