See Lauterborn in Z. wiss. Zool. lix. 1895, pp. 167, 537.
C. Scheel has seen Amoeba proteus produce a brood of 500-600 young amoebulae, which he reared to full size (in Festschr. f. Kupffer, 1899).
Arb. Kais. Gesundheitsamte Berlin, xix. 1903.
Faune Rhizopodique du Bassin du Léman, 1902. See also Cash, The British Freshwater Rhizopoda and Heliozoa, vol. i., Ray Society, 1905.
Chapman, The Foraminifera, London, 1902; Lister, "Foraminifera" in Lankester's Treatise on Zoology, pt. i. fasc. 2, 1903.