226 APPLIED BACTERIOLOGY 



The ray-fungus, when grown on artificial media, develops 

 mycelial threads and spores. Spores are readily formed, 

 which are, according to Wiirtz, very resistant to heat, 

 requiring fourteen minutes' boiling to destroy their vitality. 



Pathogenesis, — The fungus may occur in nearly every part 

 of the body. In man it generally gains access by some 

 slight traumatic injury, as only two cases are on record 

 where the disease was supposed to have been contracted 

 from affected animals, and these are doubted by some 

 authorities. Cattle affected by the disease are not un- 

 common abroad, where but little importance is attached 

 to the disease. It is comparatively rare in this country, 

 being chiefly confined to Norfolk. Owing to the great 

 resistance of the spores to heat, it is obvious that the flesh 

 of animals suffering from the disease ought not to be con- 

 sidered fit for human food. 



The disease in man corresponds pretty closely to that 

 observed in animals, but there is less tendency to localisa- 

 tion, by the abundant formation of connective tissue and 

 the frequency of calcification. The tendency of the disease 

 in man is to become chronic, and it is only by the implica- 

 tion of some vital organ, or by the exhaustion following 

 prolonged suppuration, that the patient succumbs. The 

 disease spreads by continuity, and no tissue seems able 

 to resist its invasion. Besides this, second embolic foci 

 may occur, perhaps the commonest seat being the liver. 

 No doubt many cases have gone unrecognised in days gone 

 by, and have been certified as due to pysemia ; but the 

 actinomyces is not greatly inclined to suppuration, and 

 where it is kept free from contamination by other organ- 

 isms, as in the case of an actinomycosis lesion occurring 

 in the cranium, it may remain almost dormant for long 

 periods. The disease does not extend by the lymphatic 

 system, and is characterized by the appearance of a chronic 



