30 



of tears; the eyelids are closed and slightly swollen. The 

 conjunctiva becomes swollen, its blood vessels conjested and, 

 in severe cases, a purulent discharge appears. 



Fig. 7. 

 An illustration of an abscess and the attending vascularization of 

 the cornea as observed in infectious keratitis and conjunctivitis in 

 cattle. The black spot in the cut represents the yellow abscess and 

 the radiating lines the blood vessels in the cornea. 



Young animals seem to have a general fever, hanging of 

 head, loss of appetite, and consequent emaciation; loss of 

 appetite, etc., is most probably the result of pain instet^d of 

 fever. These symptoms continue to increase for the first 

 eight or ten days. About the third day from the first ap- 

 pearance of the disease, the cornea will exhibit a small deli- 

 cately clouded spot, near its centre, which will gradually ex- 

 tend over the entire cornea, giving it a milk white appear- 

 ance. The centre of the opaque cornea is at first pearly 

 white in color, but in a short time a straw colored or yellow 

 spot appears ; this spot signals the formation of an abscess. 

 The cornea at the yellow spot is rough and surrounded by a 

 wall of thick, swollen, pearly white tissue. From this yel- 

 low centre (see Fig. 7) numerous blood vessels take their 

 course toward the sclerotic border of the cornea. The yellow 

 centre is generally longer from side to side, shorter from 

 above to below, and is said to be occasionally mistaken for 



