CHAPTER IX. 



THE DISEASES CAUSED BY THE MOLDS, YEASTS, 

 AND HIGHER BACTERIA. 



REFERRING back to the classification of the fungi 

 given in chapter ii, there still remains to be con- 

 sidered the hyphomycetes, or molds, and the blasto- 

 mycetes, or yeasts. Under the head of higher bacteria 

 are organisms having characters that make it difficult 

 to classify them either as molds or yeasts. The most 

 important of the diseases caused by the higher bac- 

 teria is: 



ACTINOMYCOSIS. 



This is an infection generally running a chronic 

 course, caused by the actinomyces, or ray fungus. It 

 prevails chiefly among cattle; but sheep, dogs, cats, 

 horses, and swine are also susceptible. It occasionally 

 occurs in man. 



The parasites can be seen by the naked eye, in 

 pus from the abscesses, as minute, yellow masses, 

 often called sulphur granules. If the granules are 

 examined under the microscope they are found to be 

 made up of a central thick mass of filaments which 

 radiate at the periphery. It is because of this radial 

 arrangement that the parasite is called the ray fungus. 

 The ends of the filaments are often club-shaped. 



The infection is located most often about the 



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