1. A small spherical structure. 2. A sporangiallike structure filled with endospores at maturity, produced within tissue and in vitro by Coccidioides immitis. [LL. sphaerula, dim. of L. sphaera, sphere, ball]
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sphe·rule (sfērґūl) [L. sphaerula little ball] 1. a small sphere. 2. a type of spherical, multinucleate cell seen in the parasitic stage of Coccidioides immitis, in which endospores are developed.Medical dictionary. 2011.