Etiology, Pathogenicity. 671 



In some respects they are similar to those found by Wolf & Israel 

 in subcutaneous abscesses and fistulae as well as in exudates of serous 

 cavities in man. 



Culture. On artificial media the fungus will grow only at body 

 temperature, at first only anaerobically, but after repeated transfers 

 to new media it will thrive also aerobically. In the deeper layers of 

 the agar medium white, mulberry-like colonies appear in the course 

 of 3 or 4 days, which consist of long branched threads with club-shaped 

 terminals, or of short rods and spore-like structures, easily stained after 

 Gram in bouillon, granules as large as pin heads develop in the course 

 of 4 to 6 days, the medium remaining perfectly clear. Milk is not 

 coagulated although its reaction becomes distinctly acid. 



Pathogenicity. The intraperi- 

 toneal administration of pure cultures 

 in mice produces pus foci as large 

 as peas on the peritoneum, while sub- 

 cutaneous inoculation of rabbits m 

 followed by the development of nod- 

 ules approaching the size of hazel- 

 nuts, consisting of a fatty or cal- 

 careous substance surrounded by 

 fibrous tissues. Similar treatment of 

 dogs is followed in the course of a 

 few^ days by the development of firm ^'^s- 109- f^treptothrix cams. 



nodules which subsequently disappear Pleurae exudate; Fuchsin stain. 



or become converted into cold ab- 

 scesses, the slimy^ reddish-gray odorless pus of wdiich contains 

 streptothrix mycelia. Guinea pigs, calves and monkeys resist 

 experimental infection. 



In the brain of a dog that had died after several weeks of illness 

 Trolldenier found numerous light grayish-white foci ranging in size 

 to that of a pea, some of which contained purulent centers. One of 

 the bronchial lymph glands was greatly enlarged and contained a 

 slightly purulent substance in its interior. Mycelia similar to those 

 described could be demonstrated in the cerebral nodes and in the affected 

 bronchial lymph gland. These mycelia would grow on artificial media 

 at room temperature under aerobic conditions. On agar the colonies 

 subsequently developed yellow centers, while their periphery remained 

 white (actinomyces bicolor). These cultures were pathogenic for mice, 

 guinea pigs, rabbits and dogs. Jochim described the same fungus in 

 a culture obtained from a dog with a phlegmonous condition in the 

 cervical region and numerous nodules in the internal organs. 



Symptoms and Anatomical Changes. The disease usually 

 manifests itself by the appearance of a peculiar inflammation 

 of the pleura or peritoneum, in the course of which purulent or 

 reddish-gray, cloudy exudate accumulates in the respective body 

 cavities. Pronounced symptoms of fever are absent. White 

 granules of the size of pin heads may be recognized in this 

 exudate by the unaided eye, while the pleura is covered with 

 fibrous masses; the lungs occasionally contain firm, gray nod- 



