1. Ephrussi, B., Hottinguer, H., and Chiménes, A. M., Ann. Inst. Pasteur, 76, 351 (1949).
2. Slonimski, P. P., Ann. Inst. Pasteur, 76, 510 (1949).
3. Slonimski, P. P., and Ephrusst, B., Ann. Inst. Pasteur, 77, 47 (1949).
4. Ephrussi, B., L'Héritier, Ph., and Hottinguer, H., Ann. Inst. Pasteur, 77, 64 (1949).
5. This compound, kindly given to U9 by Prof. Adrien Albert, has been found to be particularly active (Marcovich, H., unpublished).