P9102) Red Blood Cells in Trypanosomiasis. 243 
three times in large volumes of 0°9-per-cent. sodium chloride solution under- 
went a spontaneous agglutination in the entire absence of serum. Indeed, 
in one or two instances, where the animals exhibited an extreme degree of 
auto-agglutination, some difficulty was experienced in obtaining an even 
suspension of the erythrocytes. The probable explanation of this spontaneous 
agglutination is that it was due to the absorption of agglutinin from the 
plasma by the red cells immediately after the blood was shed into the cold 
citrated saline solution. , 
This difficulty was obviated by collecting the blood in warm citrate solution 
and then rapidly centrifugalising and decanting off the citrated plasma. The 
red cells were then washed thrice in warm normal saline solution. Suspen- 
sions prepared in this way exhibited no tendency to spontaneous clumping. , 
It might be mentioned in this connection that Klein* has succeeded in 
obtaining agglutinating solutions by grinding up with quartz sand the 
well-washed erythrocytes of certain animals (rabbit, dog, hen, and guinea-pig). 
These extracts sometimes agglutinated the red cells of other animals, and 
frequently also the erythrocytes of the same kind of animal, and even those 
of the same animal. " 
Absorption of Agglutinin by Red Cells—Experiment. To one volume of the 
citrated plasma of Rabbit 896 (infected with 7. dimorphon), which caused 
great agglutination when added to its own red cells and to those of normal 
rabbits, were added five volumes of the undiluted well-washed red cells of 
the same animal. The mixture was then divided into two equal portions, 
A and B. A was placed in the incubator at 37° C. and B in the ice chest at 
0° C. At the end of three hours the extracted plasmas were separated from 
the red cells by centrifugalisation, and were examined for auto- and_iso- 
agelutinins. eae 
able IT. 
Equal volumes of extracted plasma and erythrocyte 
suspension used. Temp. of experiment 0° C. 
Result. 
5 per cent. suspension of 
washed erythrocytes in Extracted plasma. 
normal saline solution. 
val bith S Ges. y oaurit ae acumen’ 
cy oO i a ei i ir 
Complete agglutination in 10 mins. 
No agglutination in 60 mins. 
Complete agglutination in 10 mins. | 
Slight agglutination in 60 mins. 
Ce We 
* “Beitrage zur Kenntniss der Agglutination rother Blutkérperchen,” ‘ Wien. Klin. 
Woch.,’ 1902, No. 16, p. 413. 
