The plague of the Antonines seems to have varied in different parts of the Empire and at different times of its devastating career.[18] Occasionally it seems to have taken the appearance of smallpox, sometimes of typhus, and perhaps at times an infusion of bubonic plague may have thrust in its frightful form. It would be much easier for after generations to guess at the truth if only poor Galen had not taken wing and fled; for he was an acute clinician. At its first onset he fled to Campania and, finding no safety there, took ship to Pergamos. Thence, after two years’ absence, he returned at the urgent summons of the emperor, Marcus Aurelius Antoninus, and after a brief stay in Rome rejoined him again at Aquileia. But there was no rest for his weary soul; again pestilence pursued him. The thing would be comic if we could forget the frightful misery of mankind when the foundations of civilisation were crumbling before the assaults of micro-organisms. Man was engaged in one of his greatest battles to the death against the wild; and the rat, the body-louse, and the direct infection of smallpox were apparently leagued in an assault upon his works. It is a dramatic thing to stand before the great statue of Marcus Aurelius at the head of the Capitoline steps in Rome, near the smell of the caged wolves, and to ponder that the real enemy of that somewhat tedious emperor was, not the Quadi or the Marcomanni, but, unknown to himself, if Dr. Crawfurd is right, the ignoble body-louse and the squeaking, fighting, greedy Mus Decumanus.[19] And yet he sits there so proudly upon his wonderful horse, looking every inch an emperor yet unable to cast even a moral maxim at his ignoble foes.