488 MICRO-ORGANISMS AND DISEASE [chap. 



arranged fibres and clubs which Professor Harz designated 

 acttnotnyces, or ray fungus ; the disease it causes is therefore 

 called actinojnycosis. Israel i next observed a disease in the 

 human lung, in which he found a mycelial fungus ; this was 

 afterwards identified by Pomfick as the same ray fungus 

 seen by Bollinger in the tumours of cattle. Pomfick himself 

 published ^ several cases of actinomycosis in man. Since 

 these observations a large number of cases in cattle, pigs, 

 and in man have been published, in which tumours, abscesses, 

 and suppurations, &c., were found in one or the other of 

 the following organs : in the jaw, skin, tongue, pharynx, 

 larynx, lung, intestine, liver, brain, and which proved to be 

 due to the same parasite — actinomyces. 



In cattle the disease manifests itself by firm tumours in 

 the jaw, in the alveoli of the teeth, and particularly by a 

 great enlargement and induration of the tongue — " wooden 

 tongue.'" On making sections through this latter organ there 

 are found present in all parts microscopic tumours of small- 

 cell growth. In the centre of each tumour is a clump of 

 actinomyces. This clump is surrounded by a zone of largish 

 cells, with one to four nuclei. The periphery of the tumour 

 is made up of a fibrous capsule, with spindle-shaped cells. 

 Occasionally the tumours are to be seen also in the skin and 

 in the lung; in the latter organ they appear as whitish 

 nodules, easily mistaken for tubercles. 



As the central fungus by active growth enlarges, so the 

 tumour enlarges by new infiltration with round cells spread- 

 ing into the surrounding tissues. In a later stage the central 

 portion softens and becomes purulent : an abscess is thus 

 formed which, opening on to the surface, or into the nearest 

 cavity, soon discharges copious pus; when the abscess opens 



^ Virchow's Archiv, Band Ixxiv. 



^ Die Actinomykose des Menschen, Berlin, 1882, 



