Definition Noun : A protective case or sheath in biology : A rigid, often box-like or sac-like structure that encloses, contains, or protects something, such as a spore, pollen, or an organism during a developmental stage. Specifically in botany : A capsule or sac, especially one containing spores in mosses or pollen in seed plants. Specifically in zoology : The outer protective sheath of a pup...

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