Amoeba is a genus of protozoa that moves by means of temporary projections called pseudopods, and is well-known as a representative unicellular organism. Amoeba itself is found in freshwater, typically on decaying vegetation from streams, but is not especially common in nature. However, because of the ease with which they may be obtained and kept in the lab, they are common objects of study, both as representative protozoa and to demonstrate cell structure and function. The formation of pseudopodia and accompanying changes in form of Amoeba were observed as early as 1755 by Raesel von Rosenhof, who named it on this account the " little Proteus."