From that time forward Balfour devoted himself unremittingly to continuous research in preparation for his systematic treatise on Embryology, the plan of which he had already sketched out, and which was finally completed and published in 1881. Before this appeared, however, he had published numerous papers of great value, covering nearly the whole range of his subject. Many of these will be found in the _Quarterly Journal of Microscopical Science_, of which he was one of the editors. As an original investigator he had no equal. He was skilful in manipulation, and observed rapidly and exactly, so that no point escaped his notice. His mind was calm and wholly free from prejudice, with a singularly broad and original grasp, which enabled him to seize, with readiness and sureness, the principle which lay under a number of apparently discordant facts. At the same time, like every true genius, he was singularly modest and retiring, always ready to depreciate the value of his own work, and to put forward that of others, especially of men younger than himself. We know of many students, now rising to distinction, who owe their first success to his generous encouragement, and, we may add, in some cases to his bountiful assistance, given with a delicacy which doubled the value of the gift. It was this strong desire to encourage others to work at Natural Science that induced him, in 1875, to undertake a class in Animal Morphology, or, as it used to be called, Comparative Anatomy. At first only a few students presented themselves, and one small room at the New Museums was sufficient for their accommodation. The class, however, grew with surprising rapidity; and, after Mr Balfour’s appointment as Natural Science Lecturer to Trinity College, it became necessary to build new rooms for his use. During the year 1881 the numbers had reached an average of nearly sixty in each term; and just before he left England for the excursion which has ended so fatally he had superintended the plans for a yet further extension of the Museum Buildings. His reputation as a successful teacher soon became known far and wide; students came from a distance to work under his direction; and he received tempting offers to go elsewhere. It need no longer be a secret that, after the death of Professor Wyville Thompson, the Chair of Natural History at Edinburgh was offered to him; or that, after the death of Professor Rolleston, he was strongly urged by the leading men in Natural Science at Oxford to accept the Linacre Professorship of Anatomy and Physiology. But he was devoted to Cambridge, and nothing would induce him to leave it. His refusal of posts so honourable induced the University, somewhat tardily perhaps, to recognize his merits, and a new Professorship was established in the course of last term for that especial purpose. We extract a few sentences from the Report in which the Council of the Senate recommended this step[112]: