1. B. Camerino, G. de Caro, R. A. Boissonnas, Ed. Sandrin, andE. Stürmer, Exper.19, 339 (1963).
2. L. Bernardi, G. Bosisio, F. Chillemi, G. de Caro, R. de Castiglione, V. Erspamer, A. Glasser, andO. Goffredo, Exper.20, 306 (1964).
3. E. Schröder andK. Lübke, Exper.20, 19 (1964).
4. Compound 29 of
5. After this work was completed we learnt of a similar study by Prof.Schröder et al.7: our results point to the same conclusions.