The thing first formed; that of which there are subsequent copies or reproductions; the original.
2.
(Biol.) A first-formed organized body; the first individual, or pair of individuals, of a species. "A species is a class of individuals, each of which is hypothetically considered to be the descendant of the same protoplast, or of the same pair of protoplasts."
... appear to have had an earlier date than here assigned. Cleiveland, in his Character of a London Diurnal, says, "the original sinner of this kind was Dutch; Gallo-belgicus the Protoplast, and the Modern Mercuries but Hans en kelders." Some intelligence given by Mercurius Gallo-belgicus is mentioned in Carew's Survey of Cornwall, p. 126, originally published in 1602. These vehicles of information are often mentioned in the plays of James and ... — Lives of the Poets, Vol. 1 • Samuel Johnson