224 



THE INFECTIOUS DISEASES. 



Under the microscope these masses often appear in the form of a dense 

 group of radiating filaments with more or less bulbous ends ; hence the 

 common name "ray fungus." 



FIG. 107. ACTINOM YCF.S G ROWING IN HUM AN BRONCHUS. (The bulbed ends of the fllaments are seen in 

 the borders of the colony. The bronchus, cut lengthwise, contains purulent exudate and its wall is becoming 

 involved.) 



Characters of Actinomyces. 



The organism is readily cultivated at body temperature. It grows in delicate 

 branching threads which later show segments resembling bacilli and cocci besides bulb- 

 ous or club-shaped forms, probably resulting from degeneration ("involution forms"). 

 Successful inoculations of cultures have been made in animals. 



The organism is usually conveyed from one animal to another by inoculation or by 

 contact of the growth with a wound or an abrasion of the mucous membrane. 1 



In the examination of sputum, faeces, pus, etc. , for the presence of actinomyces, 

 the naked-eye appearances maybe of value, since the yellowish-white granules are often 

 quite visible, especially on a black background. Suspicious masses may be teased and 

 studied unstained, or stained by Grain's method. Sections of tissue may be hardened 

 in alcohol, and sections stained by Grain's method with contrast eosin stain. 



Other Organisms Resembling Actinomyces. 



Many forms of micro-organisms of similar general characters to the Streptothrix 

 actinomyces have been described, some occurring in connection with infective processes 

 in men and the lower animals of which they seem to be the excitants, others living as 

 saprophytes in various situations. Among the apparently pathogenic forms we may 

 mention the following: 



Streptothrix Madura which is found in connection with a disease commonly called 

 mycetoma or "Madura foot," frequent in the tropics and characterized by new nodular 

 growths associated with suppuration and necrosis most often affecting the foot. 2 



1 For recent bibliography of actinomycosis see ScJdeyel in Lubarsch and Ostertag's 

 "Ergebnisse," Jahrg. 5 for 1898, p. 403. 



* Consult Wright, Jouru. Exp. Med., vol. iii., p. 421, Bibl. 



