1. Barth, L. G., 1929, The Effects of Acids and Alkalies on the Viscosity of Protoplasm. Protoplasma vol. 7, p. 505.
2. Conklin, E. G., 1905, Organization and Cell Lineage of the Ascidian Egg. Journ. Acad. Nat. Sci. Phila. vol. 13.
3. Costello, D. P., 1930, The Surface Precipitation Reaction in the Egg of Chaetopterus. Anat. Record vol. 47, p. 305.
4. —, 1931, The Surface Precipitation Reaction in Marine Eggs. Anat. Record vol. 51, p. 33.
5. Heilbrunn, L. V., 1927, The Colloid Chemistry of Protoplasm. V. A Preliminary Study of the Surface Precipitation Reaction of Living Cells. Arch. f. Zellf. vol. 4, p. 246.