in anatomy, fine fibrous connective tissue occurring in networks to make up the supporting tissue of many organs. The reticular fibres are composed of randomly oriented collagenous fibrils lying in an amorphous matrix substance. The fibrils are not oriented in orderly bundles, as are collagenous fibres; hence they show slightly different chemical responses. Reticular fibres, for example, readily accept a stain of silver salts that collagenous fibres reject, and, when boiled, the fibres do not form gelatin as do collagenous fibres. See also collagen.