Report on the Pathological Anatomy of Pleura-pneumonia. 179 
the serous lining rough, and studded with small points of ec- 
chymosis. 
As the name pleuro-pneumonia implies, the inflammation of 
the pleura is a very constant part of this disease. It occurs with 
great regularity, and, on account of the striking characters of the 
lesions it causes, it is never overlooked even by the most careless 
observer. Cases do occur, however, where the pleura is not 
affected at all. I met one such by accident when studying the 
normal anatomy of the bovine lung.* 
In this case there was not the least sign of even thickening 
of the pleura, while the lung disease was well marked. 
This is the only case I have met with in which there was no 
trace whatever of pleurisy. I am informed, however, that it is 
not uncommon to find nodules of disease in the lungs of fat 
cattle, even where there has not been the least suspicion of 
disease before death, and no sign of pleural disease at all. 
In three cases, where there were several points of disease in 
different parts of the lung, the pleura covering some of them 
was found to be perfectly healthy. Thus in one case there was 
extensive disease of the left lung and pleura, and in the right 
lung there were three isolated nodules, the largest about the 
size of a cricket-ball ; and yet there was not a trace of pleural 
disease on that side, and nothing could be more definite than the 
specific characters of the diseased points of lung tissue. 
It would appear, then, that pleurisy does not invariably accom- 
pany the disease of the lung tissue ; but when the diseased focus 
is small and deep-seated, the serous membrane may escape. As 
a general rule, however, the post-mortem examination of the 
disease is not made in the earliest stage, for the lung lesion may 
I easily be overlooked, and it may remain latent for an indefinite 
I time, and therefore its duration does not at all correspond to the 
I clinical history of the disease, which generally dates from the 
ij pleural complication. 
With regard to the lesion of the pleura, I feel convinced of the 
following points : — 
1. It has the characters common to the ordinary forms of acute 
pleurisy. 
* I took from the slaughter-house a lobe of a lung as a sample of healthy 
tissue. It was taken from a very fine well-fattened young bullock which was 
not suspected, before or after slaughter, to have had anything the matter with it. 
The pleural surface of both lungs was perfectly healthy throughout, and retained 
its transparency and natural shining surface. On examining the deeper parts of 
this lobe, a small focus of well-marked pleuro-pneumonic consolidation was found, 
surrounded by a considerable area of tissue which was the seat of clear exudation. 
A piece cut off from the part of this lung I had removed was examined by 
Prof. Brown, and he considered the microscopic characters of the disease to be well 
marked. 
N 2 
