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metazoa |
2 definitions found From Webster's Revised Unabridged Dictionary (1913) [web1913]: Metazoa \Met`a*zo"a\, n. pl [NL., fr Gr ? after + ? an animal.] (Zo["o]l.) Those animals in which the protoplasmic mass, constituting the egg, is converted into a multitude of cells, which are metamorphosed into the tissues of the body. A central cavity is commonly developed, and the cells around it are at first arranged in two layers, -- the ectoderm and endoderm. The group comprises nearly all animals except the Protozoa. From WordNet r 1.6 [wn]: Metazoa n : multicellular animals having cells differentiated into tissues and organs and usually a digestive cavity and nervous system [syn: {Metazoa}, {subkingdom Metazoa}]
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