Amoeba was described in detail by

The correct option is Hirshfield.

While the amoeba was originally discovered and initially described by August Johann Rösel von Rosenhof in 1755 (who famously called it the "little Proteus"), detailed physiological, cytological, and biological descriptions of the organism's cellular structure and behavior were extensively documented in later years by researchers.
Among the choices provided, Henry I. Hirshfield is recognized for his significant scientific work and detailed studies regarding the biology and characteristics of amoebae, contributing detailed descriptions that advanced our understanding of these unicellular organisms.