I accepted with both reluctance and pleasure the invitation to deliver this the first Gifford Memorial Lecture. You can appreciate how difficult it is to prepare a lecture adequate for this occasion, for Sanford Gifford will always live in our memories through his own contributions to our literature. He wrote with a profound factual knowledge, with the intuition and acumen of a skilled investigator and with a clinical wisdom which comes only from a rare combination of intelligence and common sense—in short, his writings show all the qualities of genius and will themselves constitute a splendid and an enduring memorial. None of us, I am sure, could ever feel competent to add luster to his fame by any of our own works, but all of us would be most grateful for an opportunity to add our tribute, however small, to the memory of one for whom we had such great