KERATITIS CONTAGIOSA IN CATTLE. 
25 
never been reported to me as beginning in botli eyes at one and 
the same time, still in almost all eases it has been noticed to ex¬ 
tend to the other eye. At about the second or third day from 
the time the first eye has been observed to be affected, a very 
delicate cloudiness makes its appearance at or near the center of 
the eye, which continually increases, the membrane becoming 
thicker and thicker, and more and more opaque, which conditions 
gradually extend to the sclerotic edges; this center is at first of a 
pearly white color, and in some cases may not become more than 
a creamy white, being much thickened, but in many a small yel¬ 
lowish speck will be seen to form,which gradually becomes larger, 
the tissues over it becoming thinner and thinner; this yellowish 
spot will be seen to be surrounded by a wall of thick, swollen, 
indurated tissue of a white color, while outside of this wall will 
be more or less pearly white substance, losing itself in a bluish 
white tissue as the peripheries of the cornea are approached; see 
Fig. 1. (It will be self evident that all three fine points of sha¬ 
ding could not be illustrated to perfection except at great expense, 
hence the reader must make due allowance for illustrations in 
which it has only been endeavored to show the essential points). 
From this indurated tissue, which encloses the apostematous cen- 
4 
ter, may be seen numerous delicate blood vessels taking their 
course, in a serpentine manner, towards the scelerotic edges of the 
cornea; this vascularization is often so intense as well as so deli¬ 
cate in the character of the neoplastic vessels, as to give to the 
tissues a diffuse dark red color, even to the degree of hiding the 
larger vessels from sight; in fact, so extreme may this become 
that it will take careful observation not to be misled in assuming 
the existence of an excessive intra-corneal hemorrhage completely 
filling the anterior chamber of the eye. The latter never occurs 
however. As the processes increase in intensity, the yellowish cen¬ 
ter increases in extent, and always in a direction across the eye 
from side to side, and then below the same will be seen a mass of 
intensely vascularized tissue, much swollen, but still the overlying 
tissues will retain their normal lustre, or nearly so, while those 
over the yellowish center have become very thin and lustreless 
(Fig. II.); in many cases these abscesses rupture and the contents 
