W. L. Yakimoff and others 
41 
VI. AGGLOMERATION OF TRYPANOSOMES 1 . 
The reaction of the trypanosomes was tested with the following sera: 
(!) Normal serum from man, rabbit, horse and bull. 
(2) Serum from calf and rabbit infected with this trypanosome, 
(3) Horse anti-immune serum against anthrax, epidemic abortion, pig 
erysipelas, and cattle anti-immune serum against septicaemia and chicken 
cholera 2 . 
The results are shown in the following tables. 
Number of minutes 
after mixture of 
trypanosomes 
and serum 
Normal human serum. 
Observations 
1 
3 
4 
8 
9 
10 & 12 
20 & 43 
53 
The trypanosomes begin to unite into rosettes. 
Well-formed rosettes. 
Beginning of divergence of the trypanosomes. 
Their re-union. 
Divergence. 
In some places are seen agglomerated trypanosomes. 
Many are separated. 
All have separated. 
Normal rabbit serum. 
1 The trypanosomes rapidly unite into small groups. 
3 Numerous small rosettes. 
5 Ditto. 
8 The number of rosettes greater. 
12 Ditto. 
13 The rosettes begin to diverge. 
14 The trypanosomes begin to diverge rapidly from the rosettes. 
16 Nearly all have separated. 
1 
3 
5 
10 
14 
21 & 24 
37 
48 
Normal horse serum. 
Separate trypanosomes slightly mobile. 
Separate trypanosomes more mobile. 
Trypanosomes begin to accumulate into small groups. 
Small groups; no large rosettes. 
Separate individuals in lively movement. 
Ditto. 
All have separated. 
Ditto. 
Normal bovine serum. 
2 Numerous immobile trypanosomes. 
3 Trypanosomes moving slowly and accumulating into small groups. 
4 Small rosettes. 
6 Numerous small rosettes. 
8 In some places the rosettes are larger. 
10 All the rosettes begin to part. 
13 Many separated rosettes. 
23 All the trypanosomes have finally separated. 
1 By W, L. Yakimoff and W. T. Wasilevsky. 
2 These sera were obtained through the kindness of W. T. Routschkin, to whom our thanks 
are due. 
