138 IHE LYSIN8. 



give a condensed statement here concerning Halban's work with both 

 of these substances. He obtained sterile fetal blood drawn from the 

 placental end of the cord cut directly after birth, while the mother's, 

 blood was secured by placing small sterile dishes in the vagina after 

 the removal of the placenta. He prepared from each kind of blood 

 both defibrinated blood and sera. With these preparations he tested 

 the agglutinating and hemolytic effects of the serum of the fetus on its 

 own mother, and vice versa; also the action of the fetal serum on the 

 blood of other mothers. The results of these investigations may be 

 summed up as follows : (1) The agglutinating properties of the blood 

 of the fetus did not appear to be dependent upon those of the mother's 

 serum, inasmuch as the mother's serum frequently agglutinated mark- 

 edly, while the serum of the fetus did not agglutinate at all. Occa- 

 sionally this condition was reversed, but as a rule the agglutinating ac- 

 tion of the fetal blood was much less marked than that of the maternal. 

 (2) A like result was obtained when the action of both kinds of serum 

 was tested upon the blood of the mothers of other infants. (3) The 

 same differences were observed as a rule when the sera were mixed 

 with the blood of other individuals. (4) In no case did the serum 

 of either fetus or mother agglutinate the corpuscles of the individual 

 from which the serum was obtained. (5) In a considerable number 

 of cases the serum of the mother agglutinated the blood of the fetus 

 and the serum of the fetus agglutinated the blood of the mother. In 

 other words, the two sera acted in this respect as did sera obtained 

 from different individuals. When the serum of the mother aggluti- 

 nated the blood of other individuals it also agglutinated that of her 

 own child ; and, likewise, when the serum of the fetus agglutinated 

 the blood of other individuals it also agglutinated the blood of its 

 own mother. (6) The hemolytic action of both sera as a rule par- 

 alleled their agglutinating effects. (7) The agglutinating action of 

 both sera was tested^ on cholera cultures and showed the same reac- 

 tion with these cells as with red blood corpuscles. (8) These inves- 

 tigations show that the kind and amount of agglutinins and lysins 

 existing in the blood of the mother and the fetus differ as they would 

 between other individuals. From these studies Halban draws con- 

 clusions which may be condensed as follows : 



A. The fact that the maternal and fetal blood belong to two 

 wholly distinct circulatory systems is established. It is known that 

 the chemical properties of these two bloods differ, and Kriiger has 

 shown that the fetal blood contains only slightly more solid con- 

 stituents than the maternal blood ; while the fibrin of the former is 

 markedly less than that of the latter. Scherenziss has demonstrated 

 that the specific gravity of fetal blood is somewhat, and that of 

 fetal serum markedly, lower than that of the mother. Fetal blood 

 contains less hemoglobin and therefore its red corpuscles must be 

 richer in stroma and are more easily destroyed than the corpuscles 



