The term "plastid" was coined by German biologist Ernst Haeckel in a paper he presented in 1866, but the term was too vague. In 1883, fellow German Andreas Schimper was the first to provide a clear definition to "plastid" and note the relationship between different types.
Both Haeckel and Schimper spent time in and out of the cellular biology field. Haeckel was primarily interested in zoology and was a naturalist and one of Germany's first proponents of Darwin's theory of evolution. Schimper devoted a considerable amount of time to phytogeography and ecology. Both scientists, especially Schimper, spent many years on nature expeditions, which would dramatically influence their perspectives in their respective fields.