546 DISEASES OF THE EYES. 



tional. Professor Coleman and our best modern veterinary 

 writers all concur in this etiology; and I may add, that the 

 disease would never probably have appeared in print in any 

 other form had the subject not fallen into hands that have 

 shown themselves unqualified by experience to pen any very 

 correct or useful information about the matter." Evidently the 

 truth of Percivall's observations seems to have been overlooked, 

 facts ignored, and theories worked out, to suit each man's 

 fancy, and idiopathic conjunctivitis described as a common 

 affection. 



STAPHYLOMA, 



A disease of the eye, so named from its being thought to 

 resemble a grape. In this disease the cornea loses its trans- 

 parency, rises above the level of the eye, and even projects 

 beyond the eyelids in the form- of a whitish-coloured tumour, 

 which is sometimes smooth and sometimes rough on its surface. 



Staphyloma is not a rare disease amongst dogs ; is occasionally 

 seen in horned cattle ; but I have not seen it in the horse in its 

 true form, although a spurious staphyloma may sometimes be 

 witnessed as a result of an incision through the cornea 'projgridy 

 allowing the bulging outwards of the cornea elastica. 



Staphyloma, as occurring in the dog, seems to arise from 

 two distinct pathological conditions — 1st, a growth of a tumour 

 of a compact, solid nature upon the cornea; 2d, a bulging of 

 the cornea, caused by distension of the anterior chamber by 

 an increased secretion of its natural contents (dropsy of the 

 aqueous chambers). In this form the cornea yields to the 

 distension produced by the turgescence of the humours of tlie 

 eye, as the various serous sacs yield to an accumulation within 

 them. 



In the first form it will very often be found that a small 

 ulcerous excavation exists in the centre of the tumour, and 

 that the tendency of this ulcer is to eat its way through the 

 cornea, and destroy the eye by allowing the escape of its con- 

 tents. This form of staphyloma admits of considerable ameho- 

 ration. If an ulcer be present, it should be touched slightly 

 with the point of the nitrate of silver : this arrests the process of 

 ulceration; afterwards the thickening can be removed by excision 

 or by caustic. In dogs I have often transfixed the tumour with 



