What is Ergastic substance?
An '''ergastic substance''' is a non-[[protoplasm]] material that one can find in [[cell]]s. These are usually products of [[metabolism]]. Ergastic substances include [[crystal]]s, [[oil]] drops, [[natural gum|gums]], [[tannin]]s, [[resin]]s and other [[chemical compound|compounds]]. Some of these substances help the [[organism]] function, keep up cell structure, or are just stored food material such as oil or [[fat]]. During the life of a cell, they can appear and disappear. Ergastic substances may appear in the [[protoplasm]], in [[vacuole]]s, or in the [[cell wall]]. Ergastic substances are usually absent in tissue with dividing cells, such as [[meristem]] tissue in plants. Plant cells often store noxious substances in [[leaf]] cells as a kind of [[defence against herbivory]]. In animals storing noxious substances is done as [[defence against predation]]. Storing [[venom]] for use in biting or stings is common in some groups of animals. In general, if animals need quantity of a liquid substance they produce it with special cells in a [[gland]], and send the product to where it is needed or stored. {{biology-stub}} [[Category:Cells]] [[Category:Tissues]] [[Category:Glands]] [[Category:Organic compounds]]