Indeed Galen advises the student to dissect apes in any case, in order to prepare himself for intelligent dissection of the human body, should he ever have the opportunity. From lack of such previous experience the doctors with the army of Marcus Aurelius, who dissected the body of a dead German, learned nothing except the position of the entrails. Galen at any rate dissected a great many animals. Tiny animals and insects he let alone, for the microscope was not yet discovered, but besides apes and quadrupeds he cut up many reptiles, mice, weasels, birds, and fish.[647] He also gives an amusing account of the medical men at Rome gathering to observe the dissection of an elephant in order to discover whether the heart had one or two vertices and two or three ventricles. Galen assured them beforehand that it would be found similar to the heart of any other breathing animal. This particular dissection was not, however, performed exclusively in the interests of science, since it was scarcely accomplished when the heart was carried off, not to a scientific museum, but by the imperial cooks to their master’s table.[648] Galen sometimes dissected animals the moment he killed them. Thus he observed that the lungs always sensibly shrank from the diaphragm in a dying animal, whether he killed it by suffocation in water, or strangling with a noose, or severing the spinal medulla near the first vertebrae, or cutting the large arteries or veins.[649] [Sidenote: Surgical operations.] Surgical operations and medical practice were a third way of learning the human anatomy, and Galen complains of the carelessness of those physicians and surgeons who do not take pains to observe it before performing an operation or cure. He himself had had one case where the human heart was laid bare and yet the patient recovered.[650] As a young practitioner before he came to Rome Galen worked out so successful a method of treating wounds of the sinews that the care of the health of the gladiators in his native city of Pergamum was entrusted to him by several successive pontifices[651] and he hardly lost a life. In the same passage he again speaks contemptuously of the doctors in the war with the Germans who were allowed to cut open the bodies of the barbarians but learned no more thereby than a cook would. When Galen came from Pergamum to Rome he found the professions of physicians and surgeons distinct and left cases to the latter which he before had attended to himself.[652] We may note finally that he invented a new form of surgical knife.[653] [Sidenote: Galen’s argument from design.]