[85] Quarterly Journal of Microsc. Science, 1853.
[86] Wiegmann’s Archiv., 1840, p. 196.
[87] Ueber die Erzeugung von Schnecken in Holothurier. Berlin, Bericht, 1851. Ann. Nat. Hist. 1852, v. ix. Müller’s Archiv., 1852.
[88] Natürliche Schöpfungsgeschichte, pl. x.
[89] Ann. des Sci. Nat. 1853, p. 89.
[90] Ann. des Sci. Nat. 1857, pl. vi.
[91] Cyclopædia of Anatomy and Physiology. Art. Ovum, p. 4.
[92] Thomson, loc. cit. Article, Ovum, p. 139.