314 
No. 348. Trachea.—Lesion of 6 days’ duration. The epithelium is thickened in 
places and frequently tongue-like projections, composed of epithelial cells, pro- 
ject into the lumen. There is wide-spread infection of the epithelial cells with 
cytoplasmic phases of Cytoryctes variole. In places groups of epithelial cells 
have lost their selective staining affinity and are colored an even red. Occasionally 
there is evidence of the collection of fluid within and between the degenerated 
cells. Polynuclear leucocytes are numerous and are found in the epithelium as 
well as in the submucous tissue. In places there is necrosis and accumulation of 
fibrin in the submucous tissue, such areas occurring beneath breaks in the base- 
ment membrane. The endothelial cells of the lymphatics and blood vessels of the 
submucosa are prominent and frequently contain cytoplasmic forms of Cytoryctes 
variole. Lung, 6 days after inoculation. The section shows a large bronchus and 
the surrounding lung substance. The epithelium of the bronchus is much thick- 
ened at 2 points in its circumference. In these areas the cells are more or less 
swollen and degenerated. The majority of the cells contain cytoplasmic forms of 
OCytoryctes variole. Polynuclear leucocytes are present in large numbers in the 
lumen of the bronchus, in the epithelium, and in the peribronchial tissue. The 
air cells for a considerable distance from this bronchus are filled with cells, 
fibrin, and granular precipitate. The relative amount of each of these constit- 
uents varies in different air cells, but in general the granular precipitate pre- — 
dominates in those remote from the bronchus. The cellular elements present are 
in the main polynuclear leucocytes and epithelial cells. The latter are found free 
in the air cells and also attached to the walls. In the latter situation they are 
frequently cuboidal in form and lie one beside another. Mitoses are frequently 
present in these cells. Cytoplasmic phases of Cytoryctes variole are present in 
large numbers in the epithelial cells of the air spaces. The capillaries in the 
septa between the affected air cells are injected with blood, and many polynuclear 
leucocytes are to be seen in them and migrating through their walls. 
Two other monkeys, killed 7 and 9 days after inoculation, showed small areas 
of pneumonia in their lungs. In both cases the process was characterized by pro- 
liferation of the epithelial cells lining the alveoli. No cytoryctes were demons- 
trable in these lesions. ; 
The exanthem which occurred in this series of monkeys was examined histo- 
logically and found to be similar in all respects to that which developed in the 
other variolated monkeys. 
Summary.—Four animals were allowed to survive long enough to 
show an exanthem. Six were killed at various times after the inoculation 
in order to inspect the initial lesion and to obtain material for histological 
study. In each of the former animals an exanthem appeared; in 1 on 
the eighth day, in 2 on the ninth day, and in 1 on the tenth day. The 
exanthem was of moderate extent and showed an evolution intermediate 
between that in the monkeys inoculated through a tracheotomy wound 
and the average case of variola inoculata following variolation of the skin. 
The constitutional reaction was marked. The temperature reaction 
was definite, consisting of a distinct rise simultaneously with or im- 
mediately before the appearance of the exanthem. 
The histological examination of tissues from these animals shows that 
a lesion similar to that which follows variolation of the mucous mem- 
brane of the nose, the lip, and the palate can be produced by‘inoculation 
of the epithelium of the trachea. In one animal a variolous bronchitis 
