capsule

capsule
1. (in botany)
a. A dry fruit that releases its seeds when ripe; it is formed from several fused carpels and contains many seeds. The seeds may be dispersed through pores (as in the poppy), through a lid (as in plantain), or by the splitting and separation of the individual carpels (as in the crocus). Various other forms of capsules include the silicula and siliqua.

b. The part of the sporophyte of mosses and liverworts in which the haploid spores are produced. It is borne on a long stalk (seta) and sheds its spores when mature (see peristome).


2. (in microbiology) A thick relatively rigid gelatinous layer completely surrounding the cell wall of certain bacteria (see glycocalyx). It appears to have a protective function, making ingestion of the bacterial cell by phagocytes more difficult and preventing desiccation.

3. (in animal anatomy)
a. The membranous or fibrous envelope that surrounds certain organs, e.g. the kidneys, spleen, and lymph nodes.

b. The ligamentous sheath of connective tissue that surrounds various skeletal joints.