ANTIFERMENTS 263 



On the other hand, I am of the opinion that the last word has not been 

 spoken, and while the Abderhalden test is subject to so much error as 

 to greatly reduce its practical applications, the sera of pregnant women 

 contain an antibody-like substance in such concentration as is not 

 found in the sera of males and non-pregnant women. In our own experi- 

 ments with Asnis and Freese, the Van Slyke method was found to be 

 insufficiently delicate for demonstrating the difference between the sera 

 of pregnant and non-pregant persons. In our experiments with Wil- 

 liams, 1 while reactions occurred with the sera of pregnant women and 

 tissue substrats other than placenta, and also with such substances as 

 kaolin, starch, and agar, stronger reactions occurred with placental 

 substrat; for this reason I am of the opinion that in pregnancy serum 

 there are two sets of proteolytic ferment-like substances, one normal 

 and non-specific and the second specific; while the former may be acti- 

 vated by various non-specific organic and inorganic substances re- 

 sulting in the digestion of the serum, the latter are activated by the 

 specific substrat alone, resulting in the digestion of not only the serum 

 but also to some extent of the placental substratum itself. Bronfen- 

 brenner 2 is of the opinion that the apparently specific phase of the 

 Abderhalden reaction is due to the specific combination of the antigen 

 of the substratum with the antibody of the serum, leading to a change 

 of colloidal conditions resulting in the removal of the substances which 

 inhibit digestion. 



1 Amer. Jour. Obstet. and Dis. Women and Children, 1915, Ixxii, No. 1. 



2 Jour. Lab. and Clin. Med., 1915, 1, 79. 



