1. L. Massart, G. Peeters, J. de Ley, andR. Vercauteren, Exper.3, 119 (1947);3, 154 (1947).
2. Mac Calla: stated byG. B. Wislocki, Physiol. Prev.26, 3 (1946).
3. O. Bank andH. G. Bungenberg de Jong, Protoplasma32, 489 (1939).
4. A. Albert, S. Rubbo, R. Goldaere, andY. Stone, Brit. J. exp. Path.26, 160 (1945).
5. E. Chain, Lecture at the University of Ghent on April 27th, 1947.