AMNIOTIC LIQUID 805 



The gelatinous mass referred to above, situated, during the. early periods 

 of mtra-uterme life, between the amnion and the chorion, presents a semi- 

 liquid consistence, with very delicate interlacing fibres of connective 

 tissue and fine grayish granules scattered through its substance. These 

 fibres are gradually developed as the quantity of gelatinous matter 

 diminishes and the amnion approaches the chorion, until finally they 

 form a rather soft, reticulated layer, which is sometimes called the 

 membrana media. 



Amniotic Liquid. The process of enlargement of the amnion shows 

 that the amniotic liquid gradually increases in quantity as the develop- 

 ment of the foetus progresses. At term the quantity is variable, being 

 rarely more than two pints (about one liter) or less than one pint (about 

 half a liter). In the early periods of utero-gestation it is clear, slightly 

 yellowish or greenish, and perfectly liquid. Toward the sixth month 

 its color is more pronounced and it becomes slightly mucilaginous. Its 

 reaction usually is neutral or faintly alkaline, although sometimes it is 

 feebly acid in the latest periods. It sometimes contains a small quantity 

 of albumin, as determined by heat and nitric acid ; and there usually is 

 a gelatinous precipitate on the addition of acetic acid. The following 

 table gives its chemical composition (Robin): 



COMPOSITION OF THE AMNIOTIC LIQUID 



Water ; \, . ..-. . . . . V '',, . 991.0010975.00 



Albumin and mucin . . . ... .;' . . 0.82 to 10.77 



Urea . . . . . . . . . . ; 2.00 to 3-50 



Creatin and creatinin (Scherer, Robin and Verdeil) . ; not estimated 



Sodium lactate (Vogt, Regnauld) . . . ... a trace 



Fatty matters (Rees, Mack) . . . . . 0.13 to 1.25 



Glucose (Bernard) . . . . . . . not estimated 



Sodium chloride and potassium chloride . . ; '"V 2.40 to 5.95 



Calcium chloride a trace 



Sodium carbonate . . . .... . . a trace 



Sodium sulphate . . . . . . . . a trace 



Potassium sulphate (Rees) a trace 



Calcareous and magnesian phosphates and sulphates . . 1.14 to 1.72 



The presence of certain of the urinary constituents in the amniotic 

 liquid has led to the view that the urine of the foetus is discharged in 

 greater or less quantity into the amniotic cavity. Bernard, who is cited 

 in the table of composition of the amniotic fluid as having determined 

 the presence of sugar, has shown that in animals with a multiple pla- 

 centa, the amnion has a glycogenic action during the early part of 

 intra-uterine existence. 



In regard to the origin of the amniotic liquid, it is impossible to say 



