Let me first confess to a certain degree of anxiety at the task that has been set for me. In the face of such a highly informed audience I am wide open to the charge of being a grand-matriarchal oval aspiration instructor, and I am reminded of the story of Hiram B. Goodchild who survived the Johnstown floods in Pennsylvania in 1889, in which some 2300 people were drowned as the result of a reservoir bursting. Hiram never tired of retelling his experiences, and became one of the best known bores in the state. This reputation did not pass unnoticed by St. Peter, for when he in due course arrived at the pearly gates and was asked if he had any special requests, the saint’s face fell when Hiram said that he would like to address a combined meeting of the archangels, cherubim and seraphim. After a moment the saint’s countenance cleared as he recalled that this sort of thing was the concern of the Archangel Gabriel, coming under the heading of “Communication”. Gabriel, too, was a little depressed at the request, but in the end agreed, and in due season the archangels, cherubim and seraphim were assembled in the Great Hall, with Gabriel occupying the chair. Just as Hiram B. Goodchild was about to address the congregation, Gabriel said, “I think it only fair to tell you that Mr and Mrs Noah and their family are seated in the front row”. Obviously I am no expert, and the view that I shall present is that of a generalist. I do not altogether apologise for this, for expertise can in itself present problems, as is well illustrated by what I am assured is the true story of a certain stipendiary magistrate, who regarded himself as something of an expert upon drugs. Before him was a defendant charged with illegally possessing cannabis resin, and the prosecution, being uncertain as to whether this was the genuine article or a mixture of sawdust, treacle, curry powder and glue, were seeking an adjournment to obtain an analyst’s report. The stipendiary would have none of this. “Pass it up here”, he said, “I know cannabis