ACTINOMYCES GROUP 375 



which segment into chains of conidia. All species retain the Gram 

 stain to a greater or less degree. Some are aerobic, others facul- 

 tative, and still others obligate anaerobes. Pigments are produced 

 by some species. 



Actinomyces bovis 



Synonyms. Streptothrix bovis; Cladothrix actinomyces; Strepto- 

 thrix actinomyces; Discomyces boms. 



Disease Produced. Lumpy jaw and wooden tongue (actino- 

 mycosis) in cattle, and probably related infections in other animals 

 and man. 



Harz, in 1878, gave the name Actinomyces to the ray-fungus, 

 which Bellinger, in the preceding year, had found present in the 

 characteristic tumor-like growths in cattle. 



Distribution. The infection is known from Europe and North 

 and South America. 



Morphology and Staining. In the infected tissues the organism 

 forms minute yellowish granules, sometimes large enough to be 

 readily observed by the unaided eye. These granules are made up 

 of compact masses of the organisms. Branched filaments, with a 

 more or less radial arrangement, are to be observed occupying 

 the central portion, commonly mixed with coccus-like degeneration 

 products. The margin of the granule or rosette, when examined 

 in cross-section, is found to consist of club-like enlargements of 

 the threads, showing a marked refractivity to light. The filaments 

 are slender, usually about 0.5 /w in diameter. It is believed that 

 the formation of the clubbed ends is correlated in some way with 

 the resistance of tissue to invasion. They have been variously 

 regarded as degeneration products, involution forms, and as indi- 

 cating a thickening of the sheath to protect the organism against 

 antibodies produced by the tissues. Young colonies on artificial 

 media consist of interlacing, branched threads, which tend to form 

 compact masses. These commonly break up into bacillus-like 

 segments, in a manner not unlike the formation of certain spores 

 among higher fungi, by segmentation of the hyphal threads. 

 Whether or not these correspond to the oi'dial type of spore pro- 

 duced in the higher fungi, or represent spores at all, is not known. 

 The clubbed type rarely develops in artificial media. The organism 



