In the case of botany, the path which was destined to lead furthest in the end was the apparently unpromising one of medicine. Various plants from very early times had been used as healing agents, and it became necessary to study them in detail, simply in order to discriminate the kinds employed for different purposes. It was from this purely utilitarian beginning that systematic botany for the most part originated. As we shall show in later chapters, nearly all the herbalists whose work is discussed in the present volume were medical men. The necessity for some means of recognising accurately the individual species of medicinal plants led in time to a sounder and more exact knowledge of their morphology than had ever been acquired under the influence of thinkers such as Albertus Magnus, who regarded with some contempt the idea of becoming acquainted in detail with the countless forms of plant life. The mass of observations relating to herbs and flowers, accumulated during a period of many centuries, largely for medicinal purposes, is to-day serving as the basis for far-reaching biological theories, which could never have arisen without such a foundation. It is not systematic botany alone that we owe in the first instance to medicine. Nehemiah Grew (1641-1712), one of the founders of the science of plant anatomy, was led to embark upon this subject because his anatomical studies as a physician suggested to him that plants, like animals, probably possessed an internal structure worthy of investigation, since they were the work of the same Creator. In Ancient Greece there was considerable traffic in medicinal plants. The herbalists[2] and druggists[3] who made a regular business of collecting, preparing and selling them, do not appear however to have been held in good repute. Lucian makes Hercules address Æsculapius as “a root-digger and a wandering quack[4].” The herbalists seem to have attempted to keep their business select by fencing it about with all manner of superstitions, most of which have for their moral that herb-collecting is too dangerous an occupation for the uninitiated. Theophrastus draws attention to the absurdity of some of the root-diggers’ directions for gathering medicinal plants. For instance he quotes with ridicule the idea that the Peony should be gathered at night, since, if the fruit is collected in the daytime, and a wood-pecker happens to witness the act, the eyes of the herbalist are endangered. He also points out that it is folly to suppose that an offering of a honey-cake must be made when _Iris fœtidissima_ is rooted up, or to believe that if an eagle comes near when Hellebore is being collected, anyone who is engaged in the work is fated to die within the year.