[Illustration: _Plate X_ KONRAD GESNER (1516-1565). [Print in the Botany School, Cambridge.]] Among Gesner’s numerous scientific correspondents was Jean Bauhin, a brilliant young man, twenty-five years his junior. Their acquaintance began when Bauhin was only eighteen, but, in spite of his friend’s youth, Gesner consulted him in botanical difficulties, describing him as “eruditissimus et ornatissimus juvenis.” Jean Bauhin was the son of a French doctor, a native of Amiens, who had been converted to protestantism by reading the Latin translation of the New Testament prepared by Erasmus. In consequence of his change of faith, he was subjected to religious persecution, which he avoided by retreating to Switzerland, where his sons Jean and Gaspard were born. The medical tradition seems to have been remarkably strong in the family. Both Jean and Gaspard became doctors—Gaspard, whose sons also entered the profession, being, in fact, the second of six generations of physicians. For two hundred years, an unbroken succession of members of the family were medical men. After Jean Bauhin had studied for a time at the University of Basle, he went to Tübingen, where he learned botany from Leonhard Fuchs. From Tübingen he proceeded to Zurich, and accompanied Gesner on some journeys in the Alps. After further travel on his own account, and a period at the University of Montpelier, he reached Lyons, where he came in contact with d’Aléchamps, who engaged him to assist with the ‘Histoire des plantes.’ Bauhin began to occupy himself with this work, but his protestantism proved a stumbling-block to his life there, and he was obliged to quit France. Jean Bauhin’s chief botanical work, the ‘Histoire universelle des plantes,’ was a most ambitious undertaking, which he did not live to see published. However, his son-in-law Cherler, a physician of Basle, who had helped him in preparing it, brought out a preliminary sketch of it in 1619, and, in 1650 and 1651, the _magnum opus_ itself was published, under the name of ‘Historia plantarum universalis.’ This book is a compilation from all sources, and includes descriptions of 5000 plants. The figures, of which there are more than 3500, are small and badly executed. A large proportion of them are ultimately derived from those of Fuchs. Jean Bauhin’s more famous brother, Gaspard [or Caspar] (Plate XI), was born in 1560, and was thus the younger by nineteen years. Gaspard studied at Basle, Padua, Montpelier, Paris and Tübingen. He also travelled in Italy, making observations upon the flora, and becoming acquainted with scientific men. Unfortunately he missed being a pupil of Leonhard Fuchs, since his sojourn at Tübingen took place some years after the death of the famous herbalist, who had been his brother’s teacher. The illness and death of his father in 1582 made it necessary for him to settle in Basle, where he became Professor of Botany and Anatomy, and eventually of Medicine.