SIGNIFICANCE OF THE PHENOMENON IN TRYPANOSOMAL 
INFECTIONS 
The question of the mechanism of production of auto¬ 
agglutination in trypanosomal infections is one which has frequently 
been discussed, but as yet no satisfactory explanation has been 
offered. With reference to this question it appears to me that two 
theories might be advanced to explain the development of an 
excess of auto-agglutinin in this disease. 
It has long been recognised that the blood of men and the lower 
animals suffering from trvpanosomaisis is frequently very anaemic. 
Roth the percentage of haemoglobin and the number of red 
corpuscles per cubic millimetre fall to a low level. I his is 
particularly the case in the last stages of the disease. Conceivably 
auto-agglutinin might develop in the plasma as a result of 
auto-inoculation of an animal resulting from the destruction of its 
own erythrocytes. 
There are, however, many considerations which operate against 
this view. In the first place 1 have found no constant relation 
between the development of anaemia and auto-agglutination ot 
the red cells. By the aid of systematic haemocrit examinations of 
the blood of recently infected animals it was observed that 
auto-agglutination was usually pronounced for a considerable 
period before any marked fall of the haemocrit value had occurred. 
Secondly, a marked degree of auto-agglutination comparable to 
that occuring in trypanosomiasis has not been described in any 
other of the diseases in which anaemia is a distinctive feature. 
Dudgeon* examined the blood of twenty-six cases of anaemia due 
to various causes without finding a single example of 
auto-agglutination. It is doubtful, however, whether the technique 
adopted by Dudgeon is suitable for the recognition of small 
amounts of auto-agglutinin. Then, again, it is generally 
recognised as impossible to evoke the production of auto-bodies 
experimentally by inoculating an animal with its own tissues. 
Experiment.--h rabbit was injected intraperitoneally with 
10 c.c. of its own erythrocytes which had been laked with distilled 
water and the resulting solution made isotonic with sodium chloride. 
• ' On th, Presence rf llaenueelutini.,. etc., in the Mood obtained from Infectious and Non- 
■nfectiow Dilates in Man,’ Rov. Soc. Proc., 1909. B, Vol. LXXX, p- 53 1 - 
