The acquisition of scientific knowledge, like the growth and development of a fruit tree, is both a horizontal and a vertical process. The field must be surveyed and a site chosen before the seed of knowledge is planted. The seed sprouts and begins to grow in length and breadth as it is nourished. In due course the plant matures into a full-grown tree, with a stem, numerous branches and twigs and leaves all connected together. And finally it bears fruits for harvest. Some branches may die and other new shoots spring forth in their place, but with each new shoot comes increasing rich harvest. Even so, a student who chooses to stake his future in solid state physics and material science must start from the modest beginnings of modern solid state physics that followed the discovery of quantum mechanics in 1926; and he must diligently follow the growth of the subject of material science and its technological applications (especially electronic devices) over the past half century up to its present state of maturity as a full-grown tree of knowledge with a stem, numerous branches, and plentiful ripe fruits for harvest.