K. LANDSTEINER 907 



isoantibodies in human beings, in analogy to the experiments in animals. In fact, 

 some cases were reported in which blood clinically compatible at the first transfusion 

 caused disturbances when used repeatedly. This phase, as well as the findings of ab- 

 normal isoagglntinins after several transfusions, requires further investigation. At 

 any rate, the cfmipatibility tests must be repeated prior to each transfusion. There is 

 little doubt that transfusions could incite the production of isoantibodies when in- 

 compatible blood is injected which is tolerated at first by virtue of a low agglutinin 

 content of the recipient's serum. 



The question as to the length of life of the injected corpuscles was studied by 

 Ashby.' After transfusion of group-A individuals with blood O, Ashby counted at 

 various intervals the number of inagglutinable blood cells in the recipient's circula- 

 tion and found the injected blood still present after thirty to one hundred days. In- 

 compatible blood disappears much more rapidly (Hopkins, Ottenberg, Jervell).^ 



Brief mention may be made of some attempts to apply the principle of the blood 

 groups to skin grafting and transplantation (Davis, ^ Shawan^). 



FORENSIC APPLICATION OF THE ISOAGGLUTINATION TEST 



The isoagglutination test has been employed in medico-legal cases to examine the 

 origin of bloodstains (Landsteiner and Richter;^ cf. Schiff,^ Lattes^. Of course, it 

 can be determined only that a particular stain does not correspond to a certain 

 blood, and it is not possible to make positive statements as to its identity. The sim- 

 plest procedure is the test for an agglutinin content in the stain by adding known red- 

 cell suspension A or B to the material or to an extract of it. A preliminary precipitin 

 test is needed to show that the stain consists of human blood, and a control with blood 

 O is useful in order to exclude other phenomena simulating isoagglutination. For the 

 discrimination of iso- and pseudoagglutination an addition of lecithin to the blood 

 suspension is recommended by Lattes. Also the absorption of sera A and B with 

 dried material has been applied for establishing the group.^ 



RACIAL DISTRIBUTION OF THE BLOOD GROUPS 



L. and H. Hirschfeld' discovered that there are significant variations in the in- 

 cidence of the blood groups among the human races. They stress particularly the 

 fact that the ratio between the factors A and B ("biochemical racial index") is highest 

 (>2) in Northern European peoples and lowest (<i) in Asiatic and African races 

 such as Mongolians and Ethiopians. It was pointed out later that the frequency of 



'Ashby, W.: J. Exper. Med., 29, 267. 1919. 



^Hopkins, J. G.: Arch. Int. Med., 6, 270. 1910; Jervell, F.: Acta pathol. et microbiol. Scandinav., 

 3, 201. 1924. 



3 Davis, J. S.: Ann. Surg., 66, 88. 1Q17. 



■f Shawan, H. K.: Am. J. M. Sc, 157, 503. 1919; cf. the experiments of Ingebrigtsen, R.: 

 /. Exper. Med., 16, 169, 1912. 



5 Landsteiner, K., and Richter, M.: Ztschr.f. Med.-Beamte, 16, 85. 1903. 



^ Schiff, F.: Deutsche Ztschr.f. gericht Med., g, 369. 1927. 



'Lattes, L.: Die Individualitdt des Blutes. Berlin: Springer, 1925. 



^ The application of the isoagglutination reactions for forensic cases of disputed paternity is dis- 

 cussed in the following chapter (by Ottenberg and Beres). 



'Hirschfeld, L. and H.: Lancet. 2, 675. 1919; Anthropologic, 29, 505. 1918-19, 



