356 CLINICAL BACTERIOLOGY. 



ing the muscles, and advancing without restraint. Thus, 

 the fungus extends from the lower jaw, along the neck to 

 the pleurae and the lungs, and through the diaphragm into 

 the abdominal cavity. Even invasion of the heart and the 

 brain has been observed. In addition to the continuous 

 advance of the disease, which usually is its dominating 

 feature, the dissemination of the fungus may take place 

 through emboli, in consequence of penetration of actino- 

 myces into the lumen of the vessels. 



The peculiar and the single characteristic feature of all 

 actinomycotic lesions is also in human beings the presence 

 of the actinomyces-granules. They vary from the size of a 

 grain of sand to that of a mustard-seed, and are coarse, dense, 

 at times calcareous, bodies of yellow color. Viewed with 

 low powers of the microscope they appear as dark, finely 

 granular globules, of roundish or irregularly nodular 

 shape. If slight pressure 'is made upon the cover-glass 

 beneath which the granules lie, they are broken up into a 

 number of smaller portions. Among the latter certain 

 radiate structures are especially characteristic, the so-called 

 actinomyces-druses (spheres), from which the fungus has ac- 

 quired its name of ray-fungus. These, however, can be 

 observed only with higher magnifications, and best after 

 staining the preparation. From a dense center there 

 radiate in every direction uniform, glistening, variously 

 ramified filaments, which enlarge toward the periphery and 

 terminate in bulbous, club-shaped swellings. There thus 

 result star-shaped figures, which have been compared with 

 closed crystalline druses or filled asters. In addition to 

 these, however, there are always present simpler structures 

 radially branched, consisting of only a small number of 

 filaments. These appear microscopically as gray, viscid, 

 sometimes more consistent, granules. They are juvenile 

 forms, which are found with especial frequency in softened 

 foci. The filaments at times exhibit divisions, and are 

 suggestive of strings of bacilli. Finally, there are present 

 also collections of spherical bodies that have been con- 

 sidered as masses of cocci. 



Gram's method, as modified by Gimther (p. 107), is well 

 adapted for staining the fungus, as is also exposure for half 

 an hour to the action of heated carbol-fuchsin solution. 



The portal of infection for the ray-fungus is also in 

 human beings generally the commencement of the diges- 



