Botany, the study of plants, occupies a peculiar position in the history of human knowledge. For many thousands of years it was the one field of (31) about which humans had anything (32) the vaguest of insights. It is impossible to know today just what our Stone Age ancestors knew about plants, (33) from what we can observe of preindustrial societies that still exist, a (34) of plants and their properties must be extremely ancient. This is logical. Plants are the basis of the food pyramid for all living things, even for other plants. They have always been enormously important to the welfare of people, not only for food, but also for clothing, weapons, tools, dyes, medicines, shelter, and a great many other purposes. Tribes living today in the jungles of the Amazon recognize (35) hundreds of plants and know many properties of each. To them botany, as such, has no name and is probable not even recognized as a special branch of “knowledge” at all.