1. 1) c. f. Y. Yokoyama and B. Suzuki: Proc. 8 (1932), 18.
2. 2) Levene & Rolf: J. Biol. Chem. 74 (1927), 713.
3. 3) Levene and Rolf: Ibid. 68 (1926), 285.
4. 4) Fränkel and Neubauer: Biochem. Z. 21 (1902), 321.
5. 1) Machlean: Lecithin etc. (1918), p. 51.