A CTINOMYCETES. 379 



originated with Harz. It is constantly to be detected in 

 the tissues and exudates of the disease of cattle known 

 as actinomycosis, " lumpy jaw," " wooden tongue," etc. 

 The typical tumor of this disease is characterized by 

 inflammation, pus formation, excessive new formation 

 of connective tissue, abscesses, cavities, and sinuses. 

 Viewed as a whole, the tumor presents points of resem- 

 blance to the osteo-sarcomatous, the scrofulous or tuber- 

 culous, and the cancerous processes. The disease occa- 

 sionally occurs in man, and according to the point of 

 entrance of the parasite may arise in the mouth, the 

 pharynx, the lungs, the intestines, or the skin. In ani- 

 mals the disease is characterized by an excessive new 

 formation of connective tissue, so that tumefaction is 

 always a conspicuous peculiarity. In man, on the other 

 hand, suppuration is the most prominent feature. 



If the purulent discharge from an actinomycotic 

 tumor be examined fresh, it will be found to contain 

 tiny yellow (sulphur color as a rule) clumps. If these 

 be examined, unstained, in a drop of physiological salt 

 solution or water under the microscope, they will be found 

 to be made up of a rosette-like mass of closely inter- 

 woven threads. (See Fig. 65.) At the centre the mass 

 may show the presence of spherical, coccus-like bodies 

 or granules, while at the periphery the free ends of the 

 threads are more or less distinctly bulbous or nodular, 

 or both, and they may show branching. Sometimes the 

 free ends of the threads are only slightly or not at all 

 swollen. 



These mycelia the actinomyces may be stained by 

 the ordinary aniline dyes, or by the Weigert or tho 

 Gram method, though by either of these procedures its 

 full structure is not, as a rule, brought out. The reason 



