The further history of the medical sects which flourished under the Ptolemies and for a short time afterward, when Alexandria became a colony of the Roman Empire, need not detain us long. Daremberg furnishes a chronological chart of the physicians who played a more or less prominent part in the work of these sects, and from this it appears that they numbered thirty-four in all--ten followers of Herophilus, fourteen of Erasistratus, and ten Empirics. Callamachur and Bacchius, who belonged to the first of these groups, deserve to be mentioned because they were its most distinguished members and because they were the first physicians who wrote commentaries on the writings of Hippocrates. In the sect of the Empirics the next in importance after Philinus of Cos is Serapion of Alexandria. Mantias, another disciple of Herophilus, gained considerable reputation from the fact that he was the first to collect together into a single treatise the different pharmaceutical formulae that were then in general use. He was also an authoritative writer on surgical topics. _Certain Branches of Medical Work Begin to Assume more Distinctly the Character of Specialties._--At the time of Hippocrates there were no specialists, or at least none who received any sort of official recognition from the general body of physicians; and yet, there were, even then, a few practitioners who devoted themselves preferably to the treatment of certain maladies, like the affections of the eye and the teeth; and, beside these, there were undoubtedly, in the larger communities, men who were ready and competent to undertake the more serious surgical operations. But even these men, as appears from the language of the so-called Hippocratic oath, could not honorably perform an operation for stone in the bladder; this particular work having been left from time immemorial entirely in the hands of the lithotomists, a class of men who performed no other kind of surgery and who, in fact, were considered outside the pale of the medical profession--merely surgical artisans.