- 438 — 
A note on the occurrence of auto-agglutination 
of the red cells in human trypanosomiasis 
By John L. TODD, M. J).. 
l'his note is ('oneerned with the occurrence of a plienomenon 
of tr^'panosomiasis, to Avhich the term <( auto-agglutination of the 
red cells » lias been applied. It ivas long ago noticed bv Kan- 
THACK, Durham and Blaxdfori) (i) that the blood cells of ani¬ 
mais which were heavilv infected with tio'panosomes often ran 
together in shapeless masses instead of forming rouleaux as they 
do normalh’. d'his dumping, or auto-agglutination, of the red 
cells gives a verv characteristic appearance to specimens of fresh 
blood mounted between a slide and a coverslip. ddie blood seems 
to be granular and the presence of auto-agglutination can be re- 
cognised, oerv easiha by the naked eye. \\"e often saw this phe- 
nomenon in animais experimentally inf-ected with trypanosomes 
and in the ordinarv, vaseline-sealed, préparations of fresh bk>od 
from cases of human trypanosomiasis. In IQ04 we wrote that: 
« Although this condition is not alwaws seen in infected bloods 
(( and is sometimes obseryed in préparations from cases who baye 
(( neyer been infected, still it is so constantly associated with 
<( the presence c)f tr_\-panosomes that bloods which « agglutinate » 
« in this manner are looked upon with the greatest suspicion >>(2). 
We concluded, therefore, that this appearance was by no means 
an infallible test for the presence of trypanosomes, but that its 
presence was sufficient to cause the patient, in whose blood it 
occurred, to be looked upon \yith the greatest suspicion as a pos¬ 
sible case of trypanosomiasis. We did not consider it necessary to 
publish the observations upon which this conclusion was based ; 
the observations are recorded in the présent note because atten¬ 
tion lias recently been directed to the presence of auto-agglutina- 
lion in human trypanosomiasis (3). 
d he French Commission, sent to the French Congo to studv 
Sleeping Sickness, also found that autoagglutination was verv 
constantl}' présent in cases of trypanosomiasis (4). 
