TUMOURS AND CANCERS. 235 



which form perceptible nodules. Many nodules becom- 

 ing confluent give rise to a tumour in the affected part. 

 That the actinomyces is the cause of the disease is demon- 

 strated by the fact that the fungus may be cultivated 

 artificially, and when introduced into a calf experi- 

 mentally will produce the disease. 



Actinomycosis is interesting pathologically, but is also 

 important from an economical point of view, and still 



FIG. 119. A tuft of Actinomyces highly magnified, showing the 

 clubs. 



more important in a sanitary respect, as quite a number 

 of cases have been placed on record in this country, but 

 more especially in Germany, which have occurred in the 

 human subject, and it is a noteworthy fact that in many 

 of the patients the disease seems to have commenced in 

 the alimentary canal. 



Sarcomata. Those tumours which pathologists term 

 sarcomata differ from those produced by the ray-fungus 



