n :  a small shallow dish of thin glass or plastic with a loose cover used esp. for cultures in bacteriology
 
Pe•tri, Julius Richard (1852-1921), German bacteriologist. Petri was an assistant to the eminent bacteriologist Robert Koch. In 1887 Petri introduced a vessel for growing bacteria that consists of two round rimmed plates, one serving as a cover for the other.
 
 
 
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