In the Botanic Garden Balfour obtained the material for the definite contributions he made to natural knowledge which are in the domain of Systematic Botany. No work in which Balfour engaged gave him more genuine pleasure than the administration of the Botanic Garden. Entering on the responsibility of its care when its repute was high, he left it on laying down office in even higher reputation, for in the McNabs--William and James--father and son--he had lieutenants of the first rank in gardening. During his regime the equipment for laboratory teaching to which reference has been made was installed, a museum to which old pupils all over the world contributed was instituted, and the Garden itself trebled in size, the latest addition, made just before his retirement, being an area to be cultivated as an arboretum for students of Forestry--a subject then beginning to claim attention. With Balfour's retirement in 1879 the link of Botany with Medicine in the University was still further weakened. Medicine was left out of the title of the Chair to which Alexander Dickson succeeded. Alexander Dickson of Hartree and Kilbucho was born at Edinburgh, 21st July, 1836. He was the second son of David Dickson of Hartree in Peeblesshire, and the representative of a family for long lairds of the estates of which, by the early death of his elder brother, he became proprietor. Educated privately, he entered the University of Edinburgh as a student of Medicine, graduating in 1860. Before graduation he had studied in Würzburg and in Berlin, particularly under Kölliker and Virchow, and after it he embarked on the stream of medical practice in Edinburgh. But that was convention--a demonstration of brass plate. His means placed him beyond the necessity of such professional work. His instinct lay in the direction of discovery of method more than in its application. During his student days he had shown a keen interest in Botany. Before graduation he had written on botanical subjects, and his thesis on graduation "The development of the flower in Caryophyllaceae" witnesses to his obsession. Whilst waiting for patients, he had continued work on embryogeny in plants, and when in 1862 the ill health of Professor Dickie at Aberdeen required the appointment of a substitute, the selection of Dickson set seal to his claims as a professed Botanist. In 1866 he succeeded Harvey as Professor in Dublin. Thence in 1868 he was translated to Glasgow as successor to Walker-Arnott, and in 1879 became Professor of Botany and Queen's Botanist in Edinburgh on the retirement of Balfour, and, holding these positions, he died in 1887.