102 
Journal of Agricultural Research 
Vol. I, No. a 
tion might be made of the development of the disease and that material 
might at the same time be available for the preparation of an antigen. 
From time to time, as these animals died, certain tissues were obtained 
which it was suspected might furnish the desired results, but although 
shake extracts of the spleens, livers, kidneys, and bone marrow, as well 
as alcoholic and acetone preparations, were employed under various 
conditions, the results were rather discouraging. 
Subsequent to this time there came under our observation publica¬ 
tions by numerous investigators who had given this subject considera¬ 
tion. It will suffice to mention the publications of Landsteiner, Muller 
and Potzl, Levaditi and Yamanouchi, Hartoch and Yakimoff, Citron, 
Weber, Manteufel, Manteufel and Woithe, Zwick and Fischer, and 
Schilling, Claus, and Hosslin. The results in these instances appeared 
to have been unsatisfactory, which was also the case in the extensive 
work on the diagnosis of dourine by the Wassermann method by Trajan 
Pavlosevici, as he concluded that while antibodies can be demonstrated 
by this method in laboratory animals infected with trypanosomes, the 
method can not be utilized in stallions affected with dourine. 
Later, Winkler and Wyschelessky, Mohler, and also Watson in their 
work on complement fixation as an aid in the recognition of trypanoso¬ 
miasis indicated the good results obtained in the diagnosis of dourine. 
Likewise, Mattes in his work on the agglutination of trypanosomes ob¬ 
tained gratifying results, while Braun also concludes that complement 
fixation can be utilized for the diagnosis of trypanosome affections. 
In the recorded publications it was observed that the more promising 
results were obtained by those who employed suspensions of pure try¬ 
panosomes. The organ extracts and other preparations of antigens 
generally used for this purpose proved unreliable. The procedure as 
recommended by various workers in obtaining an antigen from pure 
trypanosomes and using such a suspension as the antigen has also been 
tried by the writers with uniformly good results. The practical applica¬ 
tion of this procedure, however, would be very laborious and require a 
great deal of time, especially in cases where a large number of horses 
have to be tested by this method. Accordingly it was deemed advisable 
to devise a means by which an antigen could be prepared which would give 
similarly good results but would not require such delicate and laborious 
technique. In place of the specific trypanosome of dourine being util¬ 
ized, the writers selected the surra organism, as it had been previously 
ascertained by several investigators that the reaction obtained was not 
absolutely specific for any one trpyanosome infection but was rather of a 
group nature. As dourine is the only known trypanosome affection of 
horses existing in this country, the value of even a group reaction was 
immediately appreciated, and attention was directed to the carrying 
out of this idea in our diagnostic work. 
