SCIENCE BULLETIN, No. 21. 



although short period. It is thought desirable to record here the appear- 

 ance of black disease sheep in which secondary changes have not had time to 

 occur. The following is compiled from post-mortem examinations made on 

 over a hundred such cases that have been seen to die, or have been killed, 

 the examination being conducted at once. 



The carcase is usually in good condition; and although fluke disease is very 

 prevalent in the black disease localities, I have not seen an animal in the 

 advanced stages of fluke infestation, affected with black disease. This is also 

 the common opinion of sheepowners. The subcutaneous vessels are usually 

 engorged, but not invariably so. No muscular lesions have been seen. 



Either the thoracic or the abdominal cavities contain a varying amount of 

 straw-coloured, odourless exudate, usually rather turbid in the case of the 

 latter. A similar clear exudate may at times be found infiltrating the inter- 

 muscular tissues of the floor of the abdomen and, rarely, the perirenal tissues 

 also. There are no distinct changes in the lungs. Almost invariably the 

 pericardium is distended with a clear, straw-coloured exudate which soon 

 coagulates on standing. If the examination has been delayed, these exudates 

 may be found more or less blood-stained. The heart frequently shows 

 haemorrhages in the endocardium of the left ventricle, and at times on the 

 epicardium also. These endocardial haemorrhages may in some cases, however, 

 be agonal in origin. 



The liver, kidneys and spleen are congested, but there is no pronounced 

 swelling of the latter. All the livers examined have shown evidence of 

 recent fluke invasion. This organ almost invariably presents one or more 

 necrotic foci, greyish or dirty yellowish-white in colour, firm and odourless, 

 varying from J to 2 inches in diameter, usually circular but occasionally 

 elongated. The edges are irregular, but sharply circumscribed. These foci 

 may be situated anywhere in the liver substance, often superficial, but at 

 times deeply placed and then only free incision will reveal them. Not in- 

 frequently, rather circular, haemorrhagic areas up to an inch in diameter may 

 be met with in the liver also. The abdominal and thoracic lymphatic glands 

 are congested and moderately swollen. The mucosa of the abomasum ii 

 frequently congested, often in patches. In th^ latter case, it is usually most 

 conspicuous around the pylorus. Small haemorrhages may be scattered over 

 the surface of the organ. At times (but this is by no means common) 

 circular, superficial ulcers may be seen 01 the mucous membrane of the 

 abomasum. It is probable that these ulcers when they occur are really 

 peptic and of a secondary character. Certain areas of the mucosa are more 

 severely damaged by the bacterial toxin or by haemorrhage, and the digestive 

 action of the gastric juices acting on this locally injured spot leads to a loss 

 of substance, an ulcer resulting. 



The small intestines are more or less deeply congested. Occasionally they 

 are haemorrhagic, the congestion being most pronounced in the duodenum. 

 At times this is the only part of the bowel affected. The large intestine is 



