450 DISEASES OF CATTLE. 



cavity, however, does not disappear, but is soon filled with fungus- 

 like growths, which force their way outward through the opening. 



^Vhen the tumors are situated within the cavity of the pharynx 

 they have broken through from some gland, perhaps beneath the 

 mucous membrane, where the disease first appeared, and hang or 

 project into the cavity of the pharynx, either as pendulous masses 

 with a slender stem or as tumors with a broad base. Their position 

 may be such as to interfere with swallowing and with breathing. 

 In either case serious symptoms will soon appear. 



The invasion of the bones of the jaws by actinomycosis must be 

 regarded as one of the most serious forms of the disease. (Pis. XLI, 

 XLIII.) It may start in the marrow of the bone and by a slow 

 extension gradually undermine the entire thickness of the bone 

 itself. The growth may continue outward, and after working its 

 way through muscle and skin finally break through and appear ex- 

 ternally as stinking fungoid growths. The growth may at the same 

 time work its way inward and appear in the mouth. The disease 

 may also begin in the periosteum, or covering of the bone, and de- 

 stroy the bone from without inward. 



Actinomycosis of the lungs is occasionally observed, and it is not 

 improbable that it has been mistaken at times for tuberculosis. The 

 actinomyces grains are, however, easily observed if the diseased tissue 

 be carefully examined. The changes in the lungs as they appear to 

 the naked eye vary considerably from case to case. Thus, in one 

 animal the lungs were affected as in ordinary bronchopneumonia as 

 to the location, extent, and appearance of the disease process. The 

 affected lobes had a dark-red flesh appearance, with yellowish areas 

 sprinkled in here and there. (See PI. XLII, figs. 1, 2.) These 

 latter areas were the seat of multiplication of the actinomyces fungus. 

 In another case, of which only a small portion of the lungs were sent 

 to the laboratory, these were completely transformed into a uni- 

 formly grayish mass, very soft and pulp}'^ to the touch, and appear- 

 ing like very soft and moist dough. (PI. XLII, fig. 3.) The ac- 

 tinomyces grains were exceedingly abundant in this tissue, and 

 appeared when the tissue was incised as minute sulphur-yellow 

 grains, densely sprinkled through the tissue, which readily came 

 away and adhered to the knife blade. In still another case a por- 

 tion of the lung tissue w^as converted into large, soft masses from 

 1 to 3 inches in diameter, each partly inclosed in very dense con- 

 nective tissue. These soft, grayish-yellow masses likewise resembled 

 moist dough in their consistency, and the actinomyces grains, though 

 neither very distinct nor at all abundant, were easily fished out and 

 identified as such. A portion of this growth, Avhich was as large as 

 a child's head, was converted into an abscess filled with creamy semi- 

 liquid pus. 



