Definition of Protoplasm

Protoplasm is the living content of a cell that is surrounded by a plasma membrane. In some definitions, it is a general term for the cytoplasm (e.g., Mohl, 1846), but for others, it also includes the nucleoplasm (e.g., Strasburger, 1882). For Sharp (1921), "According to the older usage the extra-nuclear portion of the protoplast [the entire cell, excluding the cell wall] was called "protoplasm," which was unfortunate because we now know that the nucleus also is composed of protoplasm, or living substance in its broader sense. It is now the general custom to avoid this ambiguity by employing Strasburger's [(1882)] terms cytoplasm [coined by Klliker (1863), originally as synonym for protoplasm] and nucleoplasm ([term coined by van Beneden (1875), or] karyoplasm, [used by] Flemming [(1878)]

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)". The cytoplasm definition of Strasburger excluded the plastids (Chromatoplasm). As for the nucleus, the inclusion or not of the vacuole in the protoplasm concept is also controversial.