The dynamic state of developments within the field of the vasoactive polypeptides is reflected in the continuous series of publications appearing on this topic Thus, the proposal to con- o vene another symposium only two years after the 1969 Fiesole Symposium (Plenum Press, 1970) was received enthusiastically and with high expectation. Enthusiasm was based, undoubtedly, in part on meeting together once again in the very pleasant surroundings of Florence with most gracious and enchanting hosts. The 25th International Congress on Physiological Sciences held in Munich the following week also...