I first met T.C. Hsu in 1948 as he got off a train in Austin, Texas, having just arrived from the West Coast on his way from China. He barely spoke English. But in a year he approached fluency in the language, and in a few years he was more fluent in speaking and writing English than most of his fellow graduate students at the University of Texas. This was typical. He absorbed like a sponge, and comprehended all facets of the new culture he was being exposed to, and quickly learned to express himself with the idiom of the new language needed to further his development as a scientist. Also typical was the fact that he was generally one jump ahead of most in his understanding of biological phenomena, but he never assumed an air of superiority. Neither did he generally assume false humility, but did and still has the bearing of a person who possesses a degree of self-assurance that does not threaten others, and enables him to be at peace with himself. Perhaps this came from the influence of the Confucian and Buddhist intellectual environment that was part of his heritage. He never plays the role of the overbearing scientist who is hypercritical of everyone else's work but his own, which is, by the way, frequently a sign of insecurity.Like many of the experimental biologists of his age group he started out as a naturalist interested in everything that had the properties of life. Being of a questioning nature, it was inevitable that he graduated from merely being a passive observer of nature to a tinkerer. The dictionary says that a tinker is a bungler among other things. That's true of those of us who work in the laboratory. We are tinkers with certain ideas and objectives in mind who sometimes bungle into something quite different from our expectations. When this happens it is important that we stop being bunglers, and question why we have gotten the unexpected result. The pioneer geneticist, William Bateson, admonished us "to treasure our exceptions." As of this writing TC has spent 47 years treasuring exceptions and exercising serendipity resulting in major contribu-