In his article on The Sickness at Athens Mr. Watson Williams gives strong reasons for identifying the sickness with bubonic plague, and then goes on to say regretfully, ‘Thucydides, it is true, does not mention buboes’. But are we so sure that he does not? What are the ἕλκη which he mentions along with φλύκταιναι (ii. 49.5) as the outward manifestations of the disease? We have had no adequate explanation of these. Liddell and Scott render them as ‘plague-ulcers’, but this is obviously a conventional translation not based on any serious study of the symptoms of the sickness. Professor Page has given us a detailed discussion of Thucydides' medical vocabulary, but has shed no light on the word ἕλκος. He begins by telling us that ‘ἕλκος is a term of general reference, most commonly signifying a lesion of the soft parts of the body (the context must decide whether “sore”, “ulcer”, “wound”, or what else is intended)’; then, without any discussion of its context, we find him translating the word as ‘sores’ and finally he seeks to persuade us that the phrase ϕλυκταίναις μικραῖς καὶ ἕλκεσιν ἐξηνθηκός is equivalent to ‘crimson or dusky red spots covering the greater part of the body’. Sir William MacArthur, arguing persuasively for typhus, and Professor Shrewsbury, pressing the claims of measles, approach the problems from the medical standpoint, without any serious discussion of vocabulary, and neither offers any comment on the meaning of ‘ἕλκος. Other theorists appear to ignore it completely and concentrate on those symptoms which may be made to fit any infectious fever and particularly on those which are sufficiently vaguely described to allow of a little discreet distortion of the evidence. But surely we cannot hope to identify the sickness until we have decided what the ‘ἕλκος are, for, in the absence of laboratory tests, it is after all mainly by the skin eruptions and other external manifestations that we distinguish one infectious fever from another.