No. 6. DEPARTMENT OF AGRICULTURE. 117 



twelftih generation, from glycerinagar, the suspension being equal 

 in opacity to a twenty-fonr-hour-old culture of the typhoid bacillus in 

 bouillon. The animal soon showed signs of illness, the breathing 

 became rapid and labored, reaching 54 per minute. Extreme weak- 

 ness and depression came on, and it passed much of the time lying 

 down. On April 19, 1902, it was killed, death seeming imminent. 



Autopsy. — Weight 82 pounds. Condition fair. The anterior 

 lobes of both lungs were thickly studded with minute nodulee, aver- 

 aging 1 mm. in diameter. Blocks from these lobes sank in water 

 immediately. Both lungs were diense and solid to the feel through- 

 out. The posterior lobes were air-bearing for the most part, but 

 contained many solidified areas, which could be seen on the surface 

 as well as on section. 



The bronchial and mediastinal glands were enlarged and wet. 

 Scrapings from cut surfaces show an enormous number of tubercle 

 bacilli. In the mediastinal glands many yellowish nodules were 

 seen. The pleurae were normal. The liver was enlarged and firm 

 to the touch. No distinct nodules could be seen by the naked eye, 

 but throughout tllie substance yellowish areas were found in large 

 numbers. The surface appeared marbled. 



Tlie spleen was enlarged and very firm, but no nodules could be de- 

 tected. The kidneys showed numerous whitish areas on the surface, 

 which were found to extend quite deeply into the cortex. On sec- 

 tion many yellowish nodules w^ere seen. The tissues of the kidneys 

 were much stained with bile, and the pelvis contained a gelatinous 

 o*^ viscous material showing tihe same pigment. The peritoneum was 

 normal. 



Microscopic Exmniyiation. — The solidified portions of the lungs 

 contained large areas which are not air-bearing, the alveoli being 

 completely filled with leukocytes and epithelium, or epitheloid cells. 

 The small bronchi are filled by an exudate made up largely of leuko- 

 cytes. The central portions of the nodules stain poorly, and frag- 

 mentation of the nuclei of the cells is seen, but no distinct caseation 

 can be found. In sections stained with carbol-fuchsin innumerable 

 tubercle bacilli are seen. In other parts of the lungs which are still 

 largely air-bearing, minute nodules are found in large numbers hav- 

 ing the same general characterists as those just described. Through- 

 out the sections many tubercle bacilli are seen, and in the nodules 

 they are in clusters. In the liver no typical tubercles are found, 

 but there are many minuate nodules made up of round cells, and on 

 the borders of these a considerable number of giant cells with peri- 

 pheral nuclei occur. Sections stained with carbol-fuchsin sihow 

 large numbers of tubercle bacilli clustered in these areas. 



The spleen show^s round-cell infiltration, giant cells, and many 

 tubercle bacilli. 



