420 



BACTERIA PATHOGENIC TO MAN 



appearance of conglomerates of smaller tumors. On section the larger 

 tumors presented a tough capsule from which anastomosing septa 

 extended inward enclosing cheesy masses. Microscopic examination 

 of the tumors showed in all cases but one the presence of typical actino- 

 myces colonies, in most cases with typical "clubs." The general 

 histological appearance of the tumors was like that of actinomycotic 

 tissue. 



Wolff in a later paper reports that an animal inoculated in the peri- 

 toneal cavity with a culture of the same organism had lived a year and a 

 half. At the autopsy several tumors were found in the peritoneal cavity, 

 and in the liver a large typical tumor in which were many colonies which 

 by microscopic examination were shown to be typical club-bearing 

 actinomyces colonies. 



Naked-eye Appearance of Colonies of Parasite in Tissues. In both man 

 and animals they can be readily seen in the pus from the affected 



FIG. 131 



A typical " club "-bearing colony of actinomyces. X 325 diameters. (From Wright.) 



regions as small, white, yellowish or greenish granules of pinhead size 

 (from 0.5 to 2 mm. in diameter). When pus has not formed they lie 

 embedded in the granulation tissue. 



Microscopic Appearance. Microscopically these bodies are seen to be 

 made up of threads, which radiate from a centre and present bulbous, 

 club-like terminations (Fig. 131). These club-like terminations are 

 characteristic of the actinomyces. They are generally arranged in 

 pairs, closely crowded together, and are very glistening in appearance. 

 The threads which compose the central mass of the granules are from 

 0.3/^ to 0.5," in diameter; the clubs are from 6// to 8ft in diameter. 



The organism is stained with the ordinary aniline colors, also by 

 Gram's solution; when stained with gentian violet and by Grain's 

 method the threads appear more distinct than when stained with 

 methylene blue. The clubs lose their stain by Gram's method and 

 take the contrast stain. 



