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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