1. v. Hausen, Ann. Acad. Sci. Fennicae, A, 46, No. 3 (1936).
2. Cf. Virtanen, v. Hausen and Karström, Biochem. Z., 258, 106 (1933).
3. Virtanen, v. Hausen and Saastamoinen, Biochem. Z., 267, 179 (1938).
4. Hausen, Saubert-v., Physiologia Plantarum, 1, 185 (1948).
5. Virtanen and Linkola, Nature. 158, 515 (1946).