256 H. M. WOODCOCK. 



The history of our knowledge of these organisms is soon stated. The 

 parasite of cachexial fever and splenomegaly was first discovered by Leish- 

 man in 1900 in a splenic puncture taken, post-mortem, from a soldier 

 who had contracted Dum-dum fever. His first account of it (129) was pub- 

 lished in the spring of 1903. About this time Donovan, in Madras, found 

 these bodies in the same situation, but be appears to have been dubious 

 about their nature until be learnt of Leishman's discovery. Since then 

 many investigators have examined the parasites and published their 

 views concerning them, among others being Laveran and Mesnil (127), 

 Christophers (123), Donovan (124), and Marchand and Ledinghara (136). 

 Progress in this direction has culminated, for the time being, in the very 

 important discovery of Rogers (138) already mentioned. With regard to the 

 other type of disease, AV^rigbt (142) first ])ublished, at the end of 1903, an 

 account of tropical ulcer in which similar parasites were clearly recognised 

 and definitely described as such. Earlier writers on the Delhi boil malady 

 (e. g. Cunningham, Firth) may or may not have actually seen the same 

 organisms,' as distinct from altered leucocyte cells, etc., but from their 

 descriptions it is (juite impossible to say. Therefore the credit of the dis- 

 covery can, logically, be no more given them than can, sa}', that of first 

 finding a Trypanosome in the human blood be assigned to Barron, on the 

 strength of his loose description of a Flagellate met with in an ansemic 

 woman — which may have been anything. Quite independently of Wright, 

 and before seeing his paper, two Russian workers, Martzinowsky and 

 Bogrofit, also found the parasites in cases of " bouton d'Alep," but did not 

 publish their discovery till later. 



After these preliminaries, we may pass to the parasites 

 themselves and their relation to the host. Considering first 

 Leishman's form, which may be termed the splenic variety, 

 since it is always present in spleen punctures or smears ; 

 this is either free or intracellular, in the latter case the 

 organisms are usually parasitic in iarge uninuclear leucocytes 

 (tig. 37 11) or (and perhaps chiefly) in cells of the vascular 

 endothelium, particularly of the spleen (tig. 37 lil/), which arc 

 often packed with the little parasitic elements, becoming 

 greatly enlarged and distended (macrophages). Parasite- 

 containing cells, both leucocytes and macrophages, are also 



through camels (cf. footnote, p. 2(3(5), just as the smallpox germ is deprived 

 of its virulence by passing througli the cow, 



' It seems very improbable that Cunningham saw the real parasites; the 

 "nucleoid" bodies he describes averaged nearly three times the lineal 

 diameters of those below described. 



