676 INDEX OF INFECTIOUS DISEASES. 
rather to some inflammation resulting from any cause aggravated 
by the presence of pyogenic micrococci. 
Coryza. It is doubtful whether this affection is due to the action 
of any one specific micro-organism. Bacteria, however, play a part 
in keeping up the inflammation in acute and chronic nasal catarrh ; 
and in ozena the offensive odor of the nasal secretions seems to be 
due to the presence of certain bacteria, as Hajek’s B. foetidus ozenz. 
Cystitis. It has been shown by recent investigations that cyst- 
itis is not caused by the mere presence of most varieties of bacteria 
in the bladder, except, perhaps, by a few varieties, such as the gono- 
coccus, 528, provided it be healthy; but when the mucous membrane 
is injured by mechanical violence, or by the presence of a foreign 
body, cystitis is likely to result from the introduction of bacteria. 
The micro-organisms most frequently concerned in the development 
of chronic cystitis are the colon, 449, bacillus, the typhoid bacillus, 
the bacillus aérogenes, and varieties of the proteus bacillus. Among 
other bacteria which have been found in the bladder, and which may 
influence the production of chrovic inflammation, are the tubercle 
bacillus, staphylococcus pyogenes aureus and allied species, the uro- 
bacillus, and the urobacillus liquefaciens septicus of Krogius. 
Dengue. No specific micro-organism has been found in this dis- 
ease which would seem to bear a causal relation to it. 
Dental Caries. According to Miller (1894), who has made an 
exhaustive study of the bacteriology of dental caries, it is a mixed 
infection due to the presence of various micro-organisms in the pulp, 
cocci and bacilli being about equally frequent, with the occasional 
appearance of spiral forms. The typical pyogenic cocci are seldom 
present in the pus from the pulp, but various allied species are 
found which cause pus formation in mice. Putrefactive processes, 
also the result of bacterial action, greatly increase the action of the 
pulp cocci. 
Diarrhoea. The action of bacteria in the production of diarrhoea 
has already been referred to under cholera infantum and cholera 
nostras There is no reason to suppose that any particular micro- 
organism is the specific cause of this class of diseases, which are due 
probably to the toxins produced by various bacteria. Those which 
would seem to have most to do with the production of these troubles 
are bacilli of the colon and proteus groups. 
Diphtheria. The Klebs-Liffler bacillus, 349, is now recognized 
to be the specific cause of diphtheria. Other bacteria, however, are 
always associated with this, producing more or less of mixed infec- 
