262 



A CTINOMYCOSIS. 



filaments interlace with one another, and form an irregular 

 network which may be loose or dense ; at the periphery 

 they are often arranged in a somewhat radiating manner, 

 and run outwards in a wavy or even spiral course. They 

 also show branching, a character which at once distinguishes 

 them from the ordinary bacteria. Many colonies are 







FIG. 66. Actinomycosis of human liver, showing a colony of the 

 parasite composed of a felted mass of filaments surrounded by pus. 



Paraffin section ; stained by Gram's method and with safranin. x 500. 



chiefly constituted by filaments arranged as described 

 (Fig. 66). The filaments usually stain uniformly in the 

 younger colonies, but some, especially in the older colonies, 

 show deficiencies in the protoplasm, which may be regularly 

 segmented so as to give the appearance of a chain of bacilli. 

 Short bacillary forms may at places be seen lying closely 

 packed in masses. In other filaments the protoplasm may 



