318 AGRICULTURAL BACTERIOLOGY 



mal, and hence, like . tetanus, can not be classed as a con- 

 tagious disease. It is believed that the organism grows on 

 certain plants, as barley, and is introduced into the tissues 

 by the barley awns. It may also enter through a wound 

 in the mouth or through a hollow tooth, and possibly may 

 be inhaled. It is rarely fatal, and when death is produced, 



Fig. 57. Actinomycosis 



The jaw bone has become spongy and a portion of the teeth have been lost 

 due to the ravages of the disease 



it is due to mechanical causes, such as the interference with 

 breathing or swallowing, or to the weakening of a blood- 

 vessel by the constantly growing fungus. 



Symptoms. The first symptom when the disease is lo- 

 cated in the throat, as is most common, is a slight swelling, 

 which gradually increases in size and is hard and dense. 

 It undergoes disintegration at the center, and may dis- 

 charge a thick yellow pus. The opening may heal over, 

 only to break out again. The opening by which the content 

 of the abscess finds its way to the outside may be on the 

 surface of the body or in the mouth or throat. The sore 

 at the point of discharge may become very large and have 

 the appearance of a head of cauliflower. The growth of 

 the tumor may continue for years. The tongue may be in- 



