I am asking this question after writing an answer on English Language & Usage sent me on an expedition through the internet. The originating question asked about the meaning of the word proper after the word cell.
At first I was certain that it was a biology term, describing some sort of cell. I am not a biologist. After some pushback, I researched a bit and found what seems to be the original definition in a book from 1853.
It is a mistake to apply the word cell sometimes to the cell with a membrane, sometimes to the cell without a membrane, and sometimes to the membrane without the cell. Since the contents of the cell constitute the essential part of it (see p. 155), since it forms, before the secretion of the (cellulose-) membrane (pp. 156-167), a separate entity, possessing its own, essentially proper, membranous boundary (the primordial utricle, pp. 169-173), we must call this internal body the cell proper, unless we restrict the term cell to the enclosing wall or chamber, and give the internal body another name. If the name is restricted to the internal body, we cannot, in the great majority of cases, say that new cells are formed in the old, but merely that they are formed out of the old, for even the primordial utricle shares in the division, in the propagation of cells by division. Therefore when daughter-cells are said to be formed in the mother-cells, or to slip out from the mother-cells, or mother-cells are said to be dissolved and absorbed, these phrases must be admitted only as conveniently abbreviated expressions, "mother-cell" being here used instead of maternal cell-membrane.
(bold emphasis added)
My question is: Is cell proper considered a biology term or concept that would be understood by an expert of cellular structures?