28 
of the sub-mucosa of a bronchiole. An interesting feature 
of the microscopic anatomy of this bronchiole in relation to 
this tumor is that some of the glands extend between the 
cartilage plates into the adventitia in perfect histologic 
arrangement. This is not peculiar to this section. 
Civet. This growth was found in the lung of a civet, quite 
by accident. A piece of lung was removed for microscopical 
examination, because there seemed to be a catarrhal pneu- 
monia present. When seen under the microscope, an acute 
fibrinous pneumonia, parasites (acanthocephalus) , and the 
following growth were found. 
The area affected with the tumor formation was a bron- 
chiole without cartilage or glands. The epithelial cells of 
the mucosa were six to twelve deep, being of low cylindrical 
shape on the basement membrane, becoming cuboidal and 
finally roimd or flattened toward the lumen of the air pass- 
age. The mucosa also extends in finger-like projections 
into the surrounding tissue. Around the bronchiole are 
irregular, large nests of epithelial cells, both with and with- 
out limiting membranes. These are large, pale cells with 
vesicular nuclei. In many of these nests central coagulation 
necrosis has occurred. They are typical cancer nests, ap- 
parently from this bronchiole. They take the stain in the 
same manner as the bronchiole epithelium, active prolif- 
eration is present in both, they do not form acini, nor are 
there any glandular structures in the neighborhood. Around 
other bronchi in the section, glands are present; but while 
they are probably more numerous than normal, the arrange- 
ment of the lining cells with the basement membrane is 
perfectly normal. Other bronchi and bronchioles are af- 
fected, but the process is most marked aroimd the bronchiole 
first described. There are many alveoli in the vicinity filled 
partially or wholly with cancer cells. In this tumor there 
is no overgrowth of connective tissue. 
Here is a true squamous carcinoma which has passed 
through the epithehoma stage. 
These two neoplasms are both carcinomata, but strikingly 
different in cellular elements and arrangement. Generally 
speaking, the first reminds one of a scirrhus cancer of the 
