NAGANA 383 
Morbid anatomy. There appear to be no distinctive anatomical 
changes for this affection. The tissues generally are reported to be 
anemic and infiltrated with a serous exudate. If the edematous por- 
tions are incised a clear amber or citron colored fluid escapes. The 
spleen may be enlarged but the color and consistency are normal. 
The liver and kidneys are said to be slightly affected. 
Diagnosis. The diagnosis is made clinically from the progressive 
anemia and edema, coincident with a good appetite. The finding of 
the parasite in the blood is positive evidence. This disease is to be 
differentiated from the other affections caused by trypanosoma. 
REFERENCES 
1. Kawrnack, DursamM anp Buanprorp. On nagana or tsétsé-fly disease. Pro- 
ceedings of the Royal Society, Vol. LXIV (1898), p. 100. 
2. Kuertne. Positive Infektionsversuche mit Trypanosoma Brucei durch Glossina 
palpalis. Berl. Tierdr2. Wochensch., Bd. XXV (1909), S. 244. Ref. Journ. of Comp. 
Path. and Therap., Vol. XXII (1909), p. 256. 
3. Laveran anp Mesniz. Recherches morphologiques et expérimentales sur le 
trypanosome du nagana ou maladie de la mouche tsétsé. Ann. del’ Inst. Pasteur, Vol. 
XVI (1902), p. 1. 
4. Pier anp Braprorp. A preliminary note on the morphology and distribu- 
tion of the organism found in the tsétsé-fly disease. The Veterinarian, Vol. LXXII 
(1899), p. 648. 
5. Tserter. Die Tsétsé-Krankheit. Schweizer-Archiv fur Thierheilk., 1901, S. 97. 
Differentiation of surra, dourine, mal de caderas and nagana. 
The divergence of opinion concerning the nature of these affections 
and the specific identity of the exciting cause, renders a differentiation 
or unification of these most interesting diseases exceedingly difficult. 
Very few investigators have had the opportunity of studying all of 
them in their natural environment. The conclusion of Musgrave and 
Clegg in their recent report is worthy of consideration. They say: 
“In summing up the whole matter it appears to us, when we take into 
consideration the work done by others and add our own results, that 
we are justified in believing surra, nagana, mal de caderas, and proba- 
bly dourine, the same disease, and that all are caused by Tr. Evansii.” 
Koch, who worked with surra and nagana, considered the parasites 
and the resulting infections identical. Many others have formed 
similar conclusions. Other investigators such as Voges, Laveran and 
Mesnil and others maintain that certain differences exist. The evi- 
dence is convincing that dourine and mal de caderas are different in 
some respects from the other two. Voges’ reasons for this are: 
