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BACTERIOLOGY. 
licles, especially of the scalp, and forms yellow crusts 
about the base of the hairs. If the crusts are re¬ 
moved and examined under the microscope, the para¬ 
sites can be found in them. The disease is very 
resistant to treatment. 
Ringworm. 
This is a very common affection among children, 
and is caused by the Tinea trichophyton. There are 
three types of the parasite: the Tinea tonsurans, 
which attacks the hairs of the scalp; the Tinea sycosis, 
which attacks the hairs of the bearded part of the 
face, and the Tinea circinata, which attacks the skin. 
It starts as a slightly elevated, scaly spot, which 
gradually widens, forming a red, scaly patch, with 
raised edges. The hairs invaded by the parasites 
break off and leave the center devoid of hair. The 
disease spreads from one person to another by direct 
contact. 
