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also unable to find any parasitic organisms in the tissues. In one section only he 
encountered a single diplococcus, lying free between the infiltrating cells. In 1897 
Kuhn, (13) who examined a specimen of endemic boil, which also had not per- 
forated the skin and over which both the stratum corneum and the stratum 
Malpighium continued uninterrupted, was unable to find any protozoon-like or- 
ganisms, only large and small cocci, occurring either in chains or in clumps, and 
short, thick rods, being observed. Still more recently (1903) Babes, (9) in the 
examination of sections from a case of Biskra boil, was unable to discover the 
presence of any bacteria or protozoa. He concluded that the deseriptions of the 
histological examinations of other observers show little which is characteristic, and 
that they even differ considerably from one another. Further, he believes that we 
must still consider the etiology of Aleppo boil as unknown, and that the lesions 
probably arise from infections resulting from insect bites or represent certain 
syphilitic nodules and ulcerations. 
Jeanselme, (5) still more recently (1904), has made a careful study of a case 
of Biskra boil which the patient contracted in Algiers, and states that the fixation 
of the tissue in this case was perfect. Nevertheless, although a careful and 
detailed description of the histological appearances is given, no mention is made 
of the presence of any organism to which the origin of the boil might be 
ascribed. 
Finally, Bently (41) who examined in Assam over sixty cases of sores and ulcers 
resembling Delhi boil never encountered any bodies which suggested protozoa. 
It will be seen then from this review of the literature that, of the 
etiological factors which have been described for Oriental boil or ulcer, no 
single species of bacteria can be regarded as the sole specific cause of this 
disease. Doubtless, the pyogenic cocci or even varieties of the Proteus 
bacillus may have been responsible for the causation of many of the 
lesions, or at any rate, partly responsible for the pathological changes. 
Possibly, violent scratching of certain insect bites and secondary infec- 
tions with such bacteria may have been the exciting agents of many of 
these ulcers. Finally, it is not clear that a number of the reported cases 
of Delhi bow do not really represent certain lesions of syphilis and yaws. 
However, on turning from this class of cases, we find that in a number 
of other instances organisms other than bacteria have been considered to 
constitute the origin of the disease. As already mentioned, Cunningham 
was the first to describe peculiar parasitic organisms, which he considered 
to be protozoa, in the lesions. Firth next reported the discovery of 
similar bodies and proposed the name of Sporozoa furunculosa for them. 
The encapsulated cocci of Riehl, it seems, should hardly be considered as 
related to the bodies described by these two observers, particularly if one 
recalls the examination and report which Unna has made of one of 
Riehl’s specimens. 
No further reference in the literature to the presence of protozoa in 
this disease is found until 1898, when Borowsky believed that he had 
encountered such organisms, Schulgin in 1902 confirming his results. 
Finally, Wright in 1903, Mazinowsky and Borgow in 1904, and James 
and Plehn during the present year, have all reported the occurrence in the 
lesions of bodies which they believe to be protozoa. The descriptions 
