176 Report on the Pathological Anatomy of Pleuro-pneumonia. 
completely separated from each other, without their tissue suffer- 
ing the least injury. They are thus left hanging from the large 
bronchus, by means of their own proper broncho-vascular 
systems, just as raisins hang from the parent stalk. If they be 
now partially inflated, each lobule is seen to be a soft, irregularly 
shaped body, about the size of a filbert nut. On the pleural 
surface the outlines of the lobules can be seen to be polygonal 
areas with definite boundaries. The spaces between the lobules 
are occasionally made more prominent by means of little chains 
of air blebs, which lie in them. This seems a common patho- 
logical condition in cattle, being a form of true interlobular 
emphysema, which can also be easily produced after death by 
means of forcible inflation. 
When the delicate connective tissue, which forms at the same 
time the partition and connection between the lobules, is broken 
through, each lobule may be seen to be enveloped in a case of 
this loose tissue. This can be traced to the point of entrance 
of the vessels, where it is found to be continuous with the tissue 
of the loose sheath already described as surrounding the broncho- 
yascu)ar system. 
Careful investigation of the fine interlobular connective tissue 
shows it to be the seat of a very rich plexus of lymph-channels. 
Here and there vessels with an even outline and wall are seen, 
but it is more common to find, lying throughout the tissue, wide, 
sacculated, and irregular passages, freely intercommunicating 
one with the other. This plexus of lymph-vessels lies midway 
between two adjacent lobules, and evidently carries some of the 
lymph overflow from each of them, their lymph-channels being 
thus intimately related. 
By blowing air into an interlobular space, a number of the 
neighbouring spaces may be inflated, and thus artificial em- 
physema produced. The relations of these parts can, however, 
be much better seen by means of injection. A thin coloured 
solution may readily be made to run through the lymph-channels, 
and will be found to spread from one interlobular space to those 
immediately adjacent ; and thence it will pass along the lym- 
phatic channels of the corresponding broncho-vascular system 
already mentioned. Thus, from a single point of insertion 
under the pleura, not only can more than one interlobular space 
be injected, but also the injection finds its way along the lymph 
track, and reaches the main routes, leading towards the root of 
the lung. 
A rich set of lymph-channels may be seen beneath the pleura, 
being best marked over the interlobular spaces. Though at 
first it appears distinct, this lymph plexus is intimately con- 
nected with those of the interlobular spaces, and may be, re- 
