51 



Stefansky (1) describes two clinical types of the disease, the one 

 localized particularly in the lymph nodes, the other in the skin and 

 muscles. The glandular type was the more common. Dean (4) 

 thinks that no hne of demarcation can be drawn between these cHnical 

 types. 



Dean (4)' and Wherry (7) both mention that attention was attracted 

 to the diseased animals by the fact that they were seen abroad during 

 dayhght in an obviously sick condition. 



The skin, in a well-developed case of the disease, presents a patchy 

 alopecia coincident with thickening and nodule formation, which 

 is situated in the subcutaneous tissue. The cut surface of the 

 nodules or thickenings is hght yellow in color, is clean, dry, and 

 cheese-hke. In the region of the nodules the skin is atrophic, and 

 ulcers often form on the prominent parts of the affected area. The 

 subcutaneous fat tissue is diminished in amount. Histologically 

 the process is seen to be practically confined to the subcutaneous 

 tissue and to consist essentially in the presence of cells rich in proto- 

 plasm, with vesicular nuclei, whose cell body is more or less com- 

 pletely filled with slender acid-fast bacilli. The subcutaneous fat 

 is replaced by such a tissue. All investigators who have studied 

 the disease agree in emphasizing the similarity of the histology of 

 the lesion to that in leprosy in man. 



When the musculature is involved the muscle fibers atrophy and 

 the fibers are infiltrated with the specific bacilli. The affected 

 muscle is friable, and macroscopically grayish-white in color. 



The peripheral lymiph nodes are commonly involved, though 

 McCoy (10) reports a case in which only the pelvic and mesenteric 

 nodes were diseased, and in the Tidswell case (5) the peripheral nodes 

 were not enlarged. The typically affected nodes are enlarged, some- 

 times measuring as much as 3 centimeters in the greatest extent, 

 firm, and, on section, opaque pale yellow-white in color. In the experi- 

 mental disease the writer has frequently found the characteristic 

 bacilH of the disease in peripheral lymph nodes which were very 

 slightly enlarged and presented no macroscopic lesion. Dean (4) 

 has observed invasion of the submaxillary or sahvary glands by 

 extension from infected cervical lymph nodes. Wherry (8) notes that 

 in his cases he did not find the submaxillary or cervical glands involved, 

 which fact he contrasts with two early cases in which the skin and 

 adjacent axillary or inguinal nodes were involved. 



Microscopically the lymph nodes show large numbers of cells in 

 the sinuses similar to those in the skin lesions. Multinuclear giant 

 cells are frequently observed which may measure as much as 70 to 

 80 microns (4). The protoplasm of the cells is loaded with the 

 specific bacilli of the disease. The lymph follicles, trabeculse, and 

 capsule of the glands are also invaded by the bacilli. 



