440 ACTINOMYCETES. 



air hyphse. Pathogenic for rabbits. Typical clubs formed in the 

 animal. Actinomyces asteroides. Gasp. Page 449. 



4. Agar growth whitish-red. Conidia are formed. Beautiful clubs 

 in the animal. Actinomyces madurae. Lachner. Page 452. 



(B) Non-pathogenic varieties: 



1. Growth colorless, nutrient medium brown. Actinomyces 

 chromogenes. Gasp. Page 452. 



3. Growth colorless, nutrient medium colorless. Act. chromogenes. 

 Ga,sp. /3 alba L. and N. Page 455. 



3. Growth colorless, nutrient medium colored violet. Act. viola- 

 ceus. Gasp. Page 456. 



4. For varieties with other colors, see Gasperini's Act. carneus, 

 albido-flavus, citreus, etc., pages 451-456. 



Actinomyces bovis. Harz. 



(Plate 65.) 



Synonyms. — Actinomyces bovis Harz, Act. bovis sul- 

 phnreus Gasp., Nocardia Actinomyces de Toni e Trevisan, 

 Streptothrix Actinomyces Rossi Doria, Oospora bovis 

 Sauv. et Radais. 



Common Names. — Ray fungi, Actinomyces. 



Literature. — Israel (Yirchow's Arohiv, Bd. 74, 15; and 78, 421); 

 Bostrom (Ziegler's Beitrage, Bd. IX, 1). " Actinomykosis " in Eulen- 

 burg's Eealencyclopsedie, Bd. I, 1894, by Birch-Hirschfeld. Grill 

 (C. B. XVIII, 181). 



Microscopic Appearance. — In the body of men and 

 animals the organism forms sand-like masses, 0.2 to 0.6 

 or even as large as 1.2 mm. in diameter, of a gray, yellow, 

 red, sometimes also green color, and when young, of a 

 soft, and when older of a tougher consistency. The 

 masses are made up of a ball of threads, the threads 

 being radially arranged at the periphery and provided 

 with characteristic, club-like formations, which are to be 

 considered as derived from the gelatinous membranes of 

 the threads (Bostrom). The threads terminate in the 

 clubs, either free or with slight bud-like enlargements 

 (Fig. 20, a, b). The threads show true branching, are 

 thin (0.4-0.6/j), partly without division, partlj' apparently 

 composed of longer and shorter fragments. The sur- 

 rounding "membrane" is very delicate. In the interior 

 of the colonies, there are usually found between the 

 threads, cocci-like formations, which originate from fre- 



