836 GEOKGE K. MINOT AND AKLIE V. BOCK 



TABLE III 



Red Corpuscles of Group * 



= no agglutination + = agglutination 



1 The classification given here and referred to in the text is that given by Moss. 

 Since this paper was originally sent to the press, it has been officially recommended 

 (Jour. A. M. A., 1921, 76, 130.) that on the basib of priority the Jansky classifica- 

 tion be ad9pted, in spite of the fact that the Moss classification has been in wide 

 use in America and Europe. The Jansky classification is considered identical to 

 Moss' except that groups 1 and 4 are interchanged. However, it is not known that 

 Moss' groups 2 and 3 are actually identical to Jansky's. This is because there is 

 no evidence that anyone has compared the blood of an individual belonging to group 

 2 or 3 as determined by known sera of cells originating from Moss against the 

 blood of individuals classed by Jansky as group 2 or 3. 



When a donor is to be tested for the compatibility of his blood with 

 that of a patient, it can be accomplished in two ways. The first one 

 involves testing directly the donor's cells and the patient's serum for 

 agglutination, and the patient's cells and the donor's serum. If no agglu- 

 tination occurs with both of these combinations of cells and serum, it 

 indicates that the two individuals belong to the same group, thus their 

 bloods are compatible. If either of the tests is positive it indicates 

 that the individuals belong to different groups. These tests do not tell 

 us to what group the individual belongs. This is of no real consequence, 

 for our object is only to transfer blood which is compatible. The second 

 way in which one may determine whether a donor's blood is compatible 

 with that of a patient is to determine the blood group of each. This may 

 be done by testing the blood of each (either cells or serum) against 

 bloods (either serum or cells) whose groups are known. If both belong 

 to the same group, their blood is compatible. The blood of individuals 

 of a certain group may be given to those of another group, as is referred 

 to later, even when the subjects belong to different groups and their 

 bloods are not strictly compatible. 



The determination of the blood group of a patient and prospective 

 donor frequently simplifies the selection of a donor in that the blood tests 

 may be carried out at different times and in different places. Furthe 

 more, blood only need be taken once from the patient. However, in order 

 to control all possible errors, it is distinctly advisable just before each an 

 every transfusion to test the recipient's serum against the cells of tfo 

 selected donor. 



