49° MICRO-ORGANISMS AND DISEASE [chap. 



infection of the skin by actinomyces has been proved (E. 

 Miiller, Mitth. aus d. chirurg. Klinik, Tiibingen, Band iii., 

 3) in a case in which a wood splinter in the skin had 

 evidently been the means of providing an entrance for the 

 fungus. Both in man and cattle these various ways of 

 infection with actinomyces have been observed in many 

 cases. 



The various ways above mentioned in which the fungus 

 invades the organism at once suggest that it has its usual 

 habitat in the outside world, i.e. that it is an organism which 

 is introduced into the animal or human body from the out- 

 side, and is not directly derived from an infected animal or 

 man. It is a prevalent opinion that the natural habitat of 

 the ray fungus is on cerealia, that it lives on these parasiti- 

 cally, and through and from these enters the animal body 

 through wounds, abrasions, &c. Johne {Centralbl. f. d. 

 med. Wiss. 1881, No. 15) has shown that actinomyces 

 occurs normally in the pits and the loculi in the tonsils of 

 the pig ; in these instances there are always present bits of 

 ears of barley covered with what appeared to be ray fungus.' 

 Jensen {Deutsche Zeitschrift f. Thierined}i observed an epi- 

 demic of actinomycosis in cattle fed on barley ; and Piana 

 described actinomyces nodules in the tongue of cattle, where 

 in the midst of some of the nodules there were present 

 portions of vascular fibre tissue of corn surrounded by ray 

 fungus. Finally, Soltmann {Breslauer drztl Zeitschrift, 1885, 

 No. 3) made the remarkable observation of an actinomyces 

 abscess in man in the region of the dorsal vertebral column, 

 which was caused by the penetration (during swallowing) of 

 an ear of barley ; the abscess opened and the ear was 

 discharged. Fischer {Centralbl. fiir Chirurgie, No. 22,. 

 1890) describes a similar case: a labourer on chewing barley 

 pierced his tongue with a portion of the awn. Eight days 



