408 BACTERIA IN CROUPOUS PNEUMONIA. 
single experiment, however, the writer has seen a fatal result in a 
dog from the injection of one cubic centimetre of bloody serum from 
the subcutaneous connective tissue of a rabbit recently dead. This 
shows the intense virulence of the micrococcus when cultivated in 
the body of this animal. Pneumonia never results from subcutane- 
ous injections into susceptible animals, but injections made through 
the thoracic walls into the substance of the lung may induce a typi- 
cal fibrinous pneumonia. This was first demonstrated by Talamon 
(1883), who injected the fibrinous exudate of croupous pneumonia, 
obtained after death, or drawn during life by means of a Pravaz 
syringe from the hepatized portions of thelung, into the lungs of 
rabbits. According to Sée, eight out of twenty animals experi- 
mented upon exhibited ‘‘a veritable lobar, fibrinous pneumonia, 
with pleurisy and pericarditis of the same nature.” Gameléia has 
also induced pneumonia in a large number of rabbits, and also in the 
dog and the sheep, by injections directly into the pulmonary tissue. 
Sheep were found to survive subcutaneous inoculations, unless very 
large doses (five cubic centimetres) of the most potent virus were in- 
jected. But intrapulmonary inoculations invariably induced a typi- 
cal fibrinous pneumonia which usually proved fatal. In dogs simi- 
lar injections gave rise to a ‘frank, fibrinous pneumonia which 
rarely proved fatal, recovery usually occurring in from ten to fifteen 
days, after the animal had passed through the stages of red and 
gray hepatization characteristic of this affection in man.” 
Monti claims to have produced typical pneumonia in rabbits by 
injecting cultures of this micrococcus into the trachea. 
From the evidence obtained in these experimental inoculations, 
and that recorded relating to the presence of this micrococcus in the 
fibrinous exudate of croupous pneumonia, we are justified in con- 
cluding that it is the usual cause of this disease, and consequently 
have described it under the name Micrococcous pneumonix crou- 
pose. We prefer this to the name commonly employed by German 
authors—“‘ diplococcus pneumonis ”—because this micrococcus, al- 
though commonly seen in pairs, forms numerous short chains of 
three or four elements in cultures in liquid media, and upon the sur- 
face of nutrient agar may grow out into long chains. It would, 
therefore, more properly be called a streptococcus than a diplococcus. 
While the micrococcus of pneumonia is not usually seen in the 
blood in cases of pneumonia it is probably present in small numbers, 
and secondary infection of the kidneys appears to be a common occur: 
rence. Thus Frankel and Reiche (1894) report that in twenty-two 
cases out of twenty-four in which they had an opportunity to exam- 
ine the kidneys, this micrococcus was present. It was found espe- 
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