256 Dr. W. Yorke. Auto-Agglutination of [Nov. 2, 
become agglomerated into tight clumps, the outlines of the individual cells 
being indistinct, or even completely lost, so that the clumps appear to 
consist of red cells which have fused together into a homogeneous mass. In 
order to evoke as characteristic an appearance as possible the preparation 
should be made at the lowest temperature practicable. , 
The next point to be considered is whether auto-agglutination is a constant 
feature in trypanosomal infections. 
Martin, Leboeuf, and Roubaud* stated that in the large number of cases 
of human trypanosomiasis examined by them in the French Congo, auto- 
agelutination was always present. In the tables appearing in their report, 
the condition of the blood as regards auto-agglutination is indicated by 
numbers from 0 to 10, the cipher meaning that there is no agglutination, 
whereas the greatest degree of agglutination is indicated as 10; the inter- 
mediate figures denote intermediate degrees of agglutination. 
In view of the technique used by them—the mere examinations of cover- 
slp preparations of the fresh blood—such a classification appears to be a 
somewhat unwarrantable refinement. 
Toddt+ in a recent paper classifies as regards auto-agglutination a large 
number (1406) of cases examined by Dutton and himself in the Congo Free 
State. Of the 395 cases in which auto-agglutination was present, trypano- 
somes were found in only 183. However, as Todd himself states, probably 
because of the insufficient search for them (the cases were seen and examined 
‘on one occasion only), trypanosomes were present much more often than they 
were found. | 
Later in the same paper it 1s stated that only in three cases were trypano- 
somes not present when an extremely well marked auto-agglutination was 
recorded. One of these was a case of relapsing fever; another was a much 
emaciated marasmic individual, and the third was a case of syphilis. 
Regarding the frequency of the phenomenon in the blood of experimentally 
infected animals, it need only be stated that as a rule auto-agglutination is 
best marked in the blood of the larger animals, e.g. horse and donkey. It is 
usually also very distinct in the monkey, dog, rabbit, and goat. In the rat, — 
mouse, and guinea-pig it is generally slight or absent. 
In the ordinary course of events the infected animal shows parasites in its 
blood for some time before a distinct auto-agglutination develops. Occa- 
sionally, however, auto-agglutination appears before trypanosomes have been 
* “Rapport de la Mission d’Etudes de la Maladie du Sommeil au Congo Frangaise,’ 
1906—8, p. 281. 
+ “A Note on the Occurrence of Auto-agglutination of the Red Cells in Human 
Trypanosomiasis,” ‘ Bull. Soc. Path. Exot.,’ 1910, p. 438. 
’ 
