545 
horse does not completely destroy the agglutinating action of the 
plasma on the red blood cells of other animals, although it is to be 
noted that in most cases when the plasma had been extracted with 
five times its volume of its own red cells there was a marked 
lessening or even total disappearance of this action. This 
diminution of the agglutinating action of the plasma cannot be 
explained by mere dilution with the small amount of saline solution 
adhering to the red cells, as the plasma still caused marked 
agglutination after the addition of fifteen times its volume of o *9 
per cent, sodium chloride solution. 
It is doubtful, however, whether experiments of this kind really 
have the importance that has been assigned to them by Malkoff an 
others. , 
Landsteiner and Sturli* using normal horse and dog serum and 
eleven varieties of erythrocytes, confirmed Malkoffs observation 
that saturation of the serum with one kind of red blood cell 
deprived it of the power to agglutinate this variety, and this on y. 
They furthermore showed that red cells which had already been 
once completely agglutinated were still able to react wit a 
kind of serum, and that the new serum after the reaction a 
power to agglutinate fresh corpuscles of the same kind. Hence, as 
Landsteiner points out, the problem had assumed a very complex 
aspect, the enormous number of specific agglutinins in normal serum 
appearing uneconomic. i • 
Landsteiner and Sturl, suggest another hypothesis to explain 
these facts, namely, that during the process of agglutination 
substance passes from the red cell to the serum, and that. atter 
complete agglutination the serum, in consequence 
combination, agglutinin + corpuscle substance, can n ° ° S . , 
with red cells ofthe same kind, bu, can with those of other—1, 
By this theory they maintain that the facts can be 
the necessity for assuming the presence of an enormous number o 
differently acting substances or groups of substances in normal 
"T certain amount of support is afforded this view by Jae 
observation of Landsteiner that a watery extract of thecorpus^ 
of a turkey, when added to horse serum, almost ““P'^^on yt 
its agglutinating action on the red cells of the turkey^but only m 
- - i * c.r- i wipn Klin. Woch.. 1^1 P‘ 
• * Ueber die HamaRRlutimne normnler^Sera, Wien. 
II 
