318 DISEASES OP CATTLE. 



formed by the diseased secreting membrane of the bursal sac, and are 

 readily detachable from the subcutis of the skin. Their internal sur- 

 faces are often uneven or supplied with projections or tufted growths 

 which support a fibrous network within the tumor. 



Tumors of the knee may also assume a granular type, as the result 

 of chronic inflammation or following operative or spontaneous evacua- 

 tion of pus from the part. They are either firmly connected with the 

 skin or are detachable from it, and, when laid open, disclose a whitish 

 red, pork-like tissue surrounding a central nucleus of pus, or a fistu- 

 lous tract leading to the outer surface. They are caused by the 

 chronic inflammation which follows the bruises received by cattle in 

 lying down and in rising or they may be due to falls on uneven, hard 

 ground. 



Treatment for hygrornata. — When the swelling first appears cold 

 water should be applied, followed later by bandaging with cloths 

 wrung out of warm water. If the swelling is soft, it should be punc- 

 tured at the lowest point, and afterwards the cavity should be syringed 

 with Lugol's solution. If the tumor is hard and nonfluctuating, a 

 mercurial blister might cause absorption and at the same time pre- 

 vent further injury to the part by making it more painful, thus 

 sparing it. 



Serous cysts. — These swellings are another variety of extravasation 

 cysts, and are due to such injuries as butting, running against hard 

 objects, and shipping bruises, which are followed by an outpouring 

 of blood and lymph into the tissue spaces. These cysts develop rap- 

 idly and may reach the size of a man's head or even larger. They are 

 soft, edematous, and hot at first and contain a serous or blood- 

 tinged fluid. Later partially organized clots and shreds of a fibrin- 

 ous nature and of a gelatinous consistence are formed within, and 

 the temperature of the swelling is reduced. They appear on the sur- 

 face of the body, especially on the belly and flank of cattle. 



Treatment of serous cysts. — Treatment consists in opening the cyst 

 at the most dependent point with a sharp knife. The cavity should 

 be injected out twice daily with a 5 per cent solution of carbolic acid 

 and drainage encouraged by keeping the incision open. 



DERMOID CYSTS. 



These cysts have a wall which is almost an exact duplicate of the 

 structure of the skin, and frequently contain epidermal structures, 

 such as hair and teeth, which, in the development of the embryo, have 

 been misplaced. Thus we may find in an ovary or testicle a dermoid 

 cyst, containing a tooth or a ball of hair. Dental cysts are included 

 in the above class. 



Dental cysts.— It occasionally happens that the teeth of cattle, instead 

 of developing normally within strong supporting alveohe, remain 

 inclosed within a cystic membrane, whichassumes a tumor-like oharac- 



