{332 Pseudotuberculosis. 



septicemia results. On the other hand cultures of three weeks' growth 

 produce pseudotuberculosis in guinea pigs and are non-pathogenic for 

 rabbits. 



3. Bacillus Pseudotuberculosis Ovis. Preisz cultivated this 

 bacillus from nodules in the kidney of a sheep (described on page 633). 

 According to later investigations this bacillus is identical with that 

 causing ulcerous lymphangitis in horses (see this) and probably also 

 to that causing contagious acne of horses (see Vol. 2). Kitt demon- 

 strated its presence in broncho-pneumonia of cattle, Sivori in broncho- 

 pneumonia of sheep (see p. 636), Nocard in catarrhal pneumonia of 

 calves (see p. 165) and Carre & IBigoteau in mal rouge of sheep (see 

 p. 637), Seres & Guillaume in swine, and finally Lignieres found this 

 organism in rabbits and guinea pigs. 



In addition to the three above-named bacilli more recent investiga- 

 tions have resulted in the discovery of other bacteria as causes of 

 pseudotuberculous processes. Some of these are as follows: 



4. Bacillus of Pseudotuberculosis of Calves described by Vallee 

 (see p. 638). 



5. Bacillus Pseudotuberculosis Murium found by Kutscher in a 

 mouse that died of pseudotuberculosis ; it is immotile, sometimes staining 

 according to Gram's method, forms club-shaped growths in cultures 

 and is pathogenic for mice only. 



6. Corynethrix Pseudotuberculosis Murium described by Bongert 

 as a short rod, Gram positive in old cultures, its products are violently 

 toxic. 



Structure of the Pseudotubercle. Nodules developing in 

 the internal organs, on serous membranes or in subcutaneous 

 connective tissue and, on being viewed by the unaided eye, 

 bearing a perfect resemblance to true tubercles, but having 

 a different internal structure, are characteristic of pseudo- 

 tuberculosis. AVhile degeneration and necrosis of tlie tissue 

 elements does not occur in true tubercles except at an advanced 

 stage of their development, the tubercles of pseudotuberculosis 

 undergo cheesy degeneration at an early stage. Pseudotubercles 

 develop more rapidly and consist throughout of necrotic 

 detritus encased by a narrow peripheral layer of round cells. 

 VieAved with the unaided eye even the smallest nodules appear 

 white or yellowish wdiite ; in addition to this they are of rather 

 soft consistency, the larger ones usually being creamy or mushy. 

 Lime salts are occasionally deposited in the substance which 

 is encased by a gray, translucent, comparatively thick, tissue 

 capsule. 



Pseiulotuberculous processes in the sense above referred to manifest them- 

 selves, according to location, in the most variable morbid pictures. The Preisz- 

 Nocard bacillus in particular produces affections in horses that have long been 

 looked upon as well characterized specific forms of disease. For practical reasons 

 they will be discussed under separate headings (See lymphangioitis ulcerosa w. 

 below and acne pustulosa contagiosa in Vol. II 



