Pathology oe pulmonary diseases of the horse. 
67 
ever, that this gelatinous infiltration has anything to do with 
malleus ; it is a collateral process, which exists along with those of 
malleus, and is also a frequent complication of the same. In this 
case we cannot assert that gelatinous infiltration represents a 
stadium of malleus, for I have met with the same changes by old 
emaciated horses, which w'ere free from any intimation of 
malleus. Further proof in our favor is, that by horses diseased 
with malleus we are frequently only able to demonstrate the 
changes produced by the processes of the same upon small and 
circumscribed parts of the lungs, while gelatinous infiltration 
could be demonstrated in large sections of the lungs. By a con¬ 
siderable extension of the gelatinous infiltration very striking 
clinical phenomena often become apparent, which are condi¬ 
tioned by the, in general, locally limited pneumonia catarrhalis 
acuta. Observers have said that the processes of malleus have 
become acute, while in truth, we have before us nothing more 
than the complication of the processes of malleus with those of 
an acute pneumonia. In the clinic of our school there is, alas, 
a very abundant material for such observations, and horses 
diseased from malleus have frequently perished from this com¬ 
plication, by which intra-vitam notwithstanding the most circum¬ 
spect investigation we were unable to unquestionably diagnosti¬ 
cate malleus. The lethal termination is not, however, produced by 
malleus, but by entirely unlooked for event. When the animals 
have reclined for a long time ujpon one side anticipatory to death , 
the diseased part of the lungs upon the side in question will at 
the same time show the phenomena of hypostatic hypercemia , and 
then we do not find gelatinous infiltration, but splenization in the 
deepest situated parts of the lungs . Such parts are easily recog¬ 
nizable from the resemblance in appearance which they bear to 
the spleen. 
Gelatinous infiltration and splenization come to pass therefore 
under uncertain circumstances, and both represent the beginning 
of an inflammatory process, or a cellular infiltration, that is, the 
alveose become entirely filled with round cells. A higher grade 
of irritation undoubtedly exists upon such places, and this full 
hepatization develops cet. par. in the vicinity of the bronchi. 
