. so. a 
266 
Histological examination.—Sections of the cornea show very slight injury to 
corneal substance, and the defect completely covered over by epithelium. No 
evidence of any process other than repair. 
No. 10. Monkey inoculated on both corneas with vaccine virus No, 1. Twenty- 
four hours after the inoculation there is a roughness barely perceptible along the 
line of incision. Animal chloroformed. When the eyes were dropped into Zenker’s 
fluid, minute opaque spots appear at once along the line of inoculation. 
Histological ewamination.—The epithelium has grown over and completely filled 
the defects in the corneal substance representing the inoculation incisions. Num- 
bers of leucocytes are present in the tissue about the incisions. The epithelium 
contains many cytoplasmic phases of cytoryectes variole, which are rather small 
and oceupy cells which are apparently normal. 
No. 11. Monkey inoculated on both corneas with vaccine virus No, 1. Twenty- 
four hours after inoculation there is slight roughness along the line of incision. 
After 48 hours there is some elevation as well as roughness and a central loss 
of substance is also apparent. Animal chloroformed and tissues preserved for 
histological study. 
Histological examination —Section presents two clean cut and moderately deep 
incisions, one of which is filled with epithelium. The second incision is not 
filled in and the surface about it is denuded of epithelium for a short distance. 
Comparatively few polymorphonuclear leucocytes are present about the lesions. 
The corneal tissue beneath the incisions is edematous. On one side of the inci- 
sion, the corneal epithelium is two and a half times thicker than normally. 
Elsewhere the epithelium is thinner than normal, both near the incisions and 
for a considerable distance from them. In places, the epithelium is lifted up by 
an exudate. Cytoryctes are present in the cells of the lesion. 
No. 7. Monkey inoculated on the right cornea with vaccine virus No. 1. The 
left cornea inoculated with fresh virus obtained from a vaccine lesion of the skin 
of Monkey No. 1; duration 4 days. 
Twenty-four hours after inoculation the right cornea shows no macroscopic 
lesion, while the left cornea is slightly opaque and rough along the incision. 
Seventy hours. The right cornea shows slight elevation at the site of in- 
oculation. The left cornea is slightly rough along the line of incision. Animal 
chloroformed. When the eyes were placed in Zenker’s fluid a loss of substance 
was apparent along the lines of inoculation. 
Histological examination.—The corneal surface is denuded of epithelium over 
an area 0.5 millimeter across, surrounding the site of the inoculation incision, 
There is at no point any proliferation or thickening of the epithelial layer. 
It is thin and tapering at the border of the denuded area, and here cytoryctes 
are present in both the degenerated and the well-preserved epithelial cells. Very 
few leucocytes are found and when present are usually situated upon the denuded 
surface of the cornea, 
No. 12. Monkey inoculated on both corneas with vaccine virus No. 1. 
Forty-eight hours after inoculation there is no appreciable elevation or roughen- 
ing, but there is distortion of an image reflected on the cornea, 
Three days. The left cornea is distinctly rough at the site of the inoculation. 
The right cornea is very slightly roughened. There is no opacity of the cornea. 
A small amount of muco-purulent material is present in both conjunctival sacs. 
Four days. Condition of corneas the same. Animal killed and tissues pre- 
served for histological study. 
