24 
FRANK S. BILLINGS. 
pupil seems to protrude as though proud-flesh, or something of 
that nature grew in the center ! The above will be found to be 
an unusually good description from the hands of a layman. 
The disease first appeared in the vicinity of Lincoln, in a herd 
of dairy cows, about July 1, 1888. Its extension over them was 
very slow indeed, and although there were several horses among 
the cattle, or exposed to more or less danger of infection, the dis¬ 
ease did not extend to them, nor to the men milking and caring 
for the animals. Up to October first ten cows, out of about sev¬ 
enty-five, and seventeen calves, had become affected, when my 
observations had to cease on account of important engagements 
elsewhere. 
Clinical phenomena and gross 'pathological lesions .—The dis¬ 
ease first manifests itself by the discharge of a thin, clear watery 
fluid from the conjunctival sack; marked photophobia is an early 
symptom, the eyelids being closed and somewhat swollen, though 
the afflicted animal can open them easily enough if startled, and 
has complete control over their movements; the discharge rapid" 
ly increases in quantity, the conjunctiva becoming more and more 
swollen until, in some cases, the engorgement of the vessels be¬ 
come so intense, that its general color is almost a diffuse copper 
red ; (this has not been shown in the accompanying illustrations 
on account of the unfortunate necessity of all possible economy 
in the number of cuts;) in very severe cases the discharge be¬ 
comes purulent. While a careful examination of the diseased 
animals has shown that the rise in temperature is but very slight, 
still they present phenomena which the casual observer might 
mistake for those of high fever; their heads are held depressed, 
the ears become pendulent, and they refuse to eat and rapidly 
emaciate, while the yield of milk lessens materially ; these condi¬ 
tions augment during the first eight or ten days ; the photophobia 
correspondingly increasing; instead of fever, they must be attri¬ 
buted to the severe pain which the animal is suffering; intra-ocu¬ 
lar pressure is present to an excessive degree, but the cause there¬ 
of is entirely to besought in a marked increase in the quantity of 
fluid in the anterior chamber of the eye, the corner of which be¬ 
comes distended and very prominent. While the disease has 
