448 EQUINE CONTAGIOUS PLEURO-PNEUMONIA 
Gaffky and Luhrs found that “pieces of diseased lungs removed 
from killed foals before bacteria were present did not transmit the 
virus, even when portions were injected directly into the lungs of 
susceptible horses. This fact, combined with the earlier findings, 
that the virus is not found in the blood during any stage of the dis- 
ease, tends to support the conception that it is confined to certain 
cells. The authors believe these to be the epithelial cells of the air 
passages. This belief is based on the successful transmission of the 
disease through the bronchial secretions containing large numbers 
of these cells. The material was taken from slaughtered horses. 
In typical cases one finds in horses killed on the third or fourth day 
that the air passages are more or less filled with a yellowish, glassy, 
transparent, tenaceous secretion, that may be lifted out of the pas- 
sages with a pincette. This secretion is coughed up and observed. 
during the course of the disease; many times it is swallowed, and for 
this reason is not usually seen. In the latter stages of the disease the 
secretions contain many micro-organisms, when they lose their tena- 
cious condition, and perhaps the greater part of their infectiveness.’” 
In 1887, Schiitz described an organism which appeared as a diplo- 
coccus in tissues, but in bouillon cultures it grew in flocculi. From 
the description, it appears that it was a streptococcus, notwithstand- 
ing the fact that in the tissues it appeared more often as a diplococcus. 
According to Schiitz, cultures injected directly into the lungs by 
means of a hypodermic syringe produced the disease. The resulting 
contagious pleuro-pneumonia exhibited the same symptoms and ran a 
like course to the disease contracted in the natural manner. The 
inoculated streptococci were found in the tissues of the artificially 
produced disease. According to Schiitz, the bacteria of contagious 
pleuro-pneumonia are found most numerously in the lungs or the 
exudate on the pleuree. It is quite generally conceded that the 
streptococcus of Schiitz is a secondary invader. 
Ligniéres believed that a “cocco-bacillus” stands in an etiological 
relation to this disease and that here, as in strangles, the streptococcus 
is a secondary invader. Because of Ligniéres’ observation the French 
often refer to this disease as pasteurellosis. His theory of the etiology 
has not been confirmed. 
Moore made a bacteriological examination of the organs from five cases of fatal 
contagious pneumonia of the horse. In each case, the lungs were more or less hepa- 
tized, but the other organs were nearly normal in appearance. Without exception, « 
streptococcus appeared, usually in pure culture, from the lungs. The inoculated 
