Report on the Pathological Anatomy of Plcuro-pneumonia. 177 
garded as a part of the same general system. That wonderfully 
rich set of lymphatics, with which one is familiar in the sub- 
pleural tissue of many animals, does not appear to be so well 
developed in the ox. In comparison, at least, with those around 
the bronchi and vessels, the sub-pleural lymphatics are small. 
It seems probable that in the case of the ox the deep channels 
which accompany the blood-vessels take the place of the 
lymphatic high roads which exist under the pleura of many 
animals. 
The following points concerning the normal anatomy may be 
thus briefly recapitulated. 
1. The vascular and bronchial territories are distinctly defined 
and independent of one another. 
2. The lobules of the lung in the ox are quite distinct, and 
may be separated without injuring their air-cells. 
o. Each lobule is enveloped in a loose case of connective 
tissue, which contains a rich plexus of lymphatics. 
4. A sheath of delicate connective tissue also surrounds the 
hroncho-vascular systems, and forms the bed of large lymph- 
channels. 
5. The lymph from the interlobular spaces passes along the 
peribronchial passages. 
6. As the lymph-vessels follow the course of the broncho- 
vascular systems, those around any given system must drain the 
territory of the lung tissue supplied by that system. 
7. The sub-pleural lymphatics seem to take a less important 
share in draining the tissue than is the case in many other 
animals. 
Morbid Anatomy. 
There are few diseases in which the post-mortem appearances 
are more characteristic than in pleuro-pneumonia. So distinct 
are the characters of the advanced stage of the disease, that the 
most unscientific eye can recognise it after seeing a few cases. 
The group of morbid changes is very constant ; and, moreover, 
there is a general character which is so peculiar as to be easily 
recognised in every stage of the disease, and which has therefore 
been deemed specifically diagnostic of it. To the butcher, pleuro- 
pneumonia presents a much more simple field for speculation than 
it does to the pathologist, who recognises a number of different 
morbid changes, which seem to depend on very different causes. 
Morbid processes occur in the pleura, in the lung parenchyma, 
and in the bronchial tubes and blood-vessels. It appears con- 
venient to discuss the changes in each of these parts separately, 
in the order named, this being also the order in which they are 
met with in the post-mortem examination. 
VOL. XIV. — S. S. N 
