1910. | Red Blood Cells in Trypanosomiasis. 253 
Landsteiner points out, the problem had assumed a very complex aspect, the 
enormous number of specific agglutinins in normal serum appearing 
uneconomic. 
Landsteiner and Sturli suggest another hypothesis to explain these facts, 
namely, that during the process of agglutination some substance passes from 
the red cell to the serum, and that after complete agglutination the serum, in 
consequence of the combination, agglutinin+corpuscle substance, can no 
longer react with red cells of the same kind, but can with those of other 
animals. By this theory they maintain that the facts can be explained 
without the necessity for assuming the presence of an enormous number of 
differently acting substances or groups of substances in normal serum. 
A certain amount of support is afforded this view by the observation of 
Landsteiner that a watery extract of the corpuscles of a turkey, when added 
to horse serum, almost completely prevents its agglutinating action on the 
red cells of the turkey, but only in a very shght degree on other kinds of 
blood. This last observation was subsequently confirmed by Lazar.* 
However, unless all traces of the stromata of the red cells had been removed 
from the hemoglobin solution—and this is by no means an easy per- 
formance—an obvious explanation for this inhibiting action of such solutions 
would be that the stromata themselves had fixed the agglutinins present in 
the horse serum, and consequently there would be little, if any, left to act. 
upon the red corpuscles. Naturally, in this case, the inhibiting action would 
be specific for the variety of red cells from which the hemoglobin solution 
was made. 
The fact that the phenomenon of auto-agglutination is reversible allows 
one to approach the subject of specificity from a different point of view, 
namely, by extracting the completely agglutinated red cells with a small 
quantity of normal saline solution at 37° C., and then investigating the 
nature of the digest. ; 
Lxpervment.—To 10 cc. of defibrinated plasma of Rabbit 1035 (infected 
with 7. brucer) were added 0:2 c.c. of the red cells of the same animal. After 
allowing the mixture to stand in the ice chest for 12 hours with occasional 
stirrings the supernatant plasma was decanted off, and the clumped red 
blood cells washed four times with at least 10 times their volume of normal 
saline solution at 0° C.; 0:2 ¢.c. of normal salt solution was then added to the 
agelutinated mass of red cells and the mixture allowed to digest at 40° C. 
for half an hour. At the end of this time no trace of agglutination was 
* “Ueber die Bedeutung der lipoiden Stoffe der rothen Blutkérperchen fiir den 
Mechanismus der Agglutination,” ‘Wien. Klin. Woch.,’ 1905, p. 1012. 
