Unfortunately hitherto these two kinds of influence exerted by the genius epidemicus have been only too often confounded, and no adequate distinction drawn between epidemic diseases on the one hand and diseases subject to epidemic influence on the other. This has been especially so with regard to Venereal disease, the epidemic character of which curiously enough enquirers have felt bound to vindicate, as well at the beginning of the XVth. Century as here and there even at the present day. The baselessness of such an opinion is so perfectly obvious to anyone who weighs the matter with any care, that we really do not think it necessary to devote more pains now to proving the point, particularly as we propose to treat it more fully in another place. On the other hand Venereal disease _is_ subject to epidemic influence, in fact it is so perhaps to a greater extent than many other forms of sickness, as will be clearly shown in the course of our historical investigations. Accordingly the only question still wanting an answer is, how far such influence may have been effectual in Antiquity. This question of course presupposes the existence already of a number of diseases appearing in consequence of Venereal excesses; still we possess sufficient proof, as previously stated in the course of our enquiries into the influence of climate, to justify a provisional assumption of their existence for our immediate purpose. For openly admitting as we do our ignorance in relation to the influence of the genius epidemicus on sexual activity generally and on the individual activity of the genital organs in particular, and noting the problem to be one that can only be solved in the future, there is nothing else left us to investigate here but this, viz. _the influence of the genius epidemicus in reference to the forms taken and course followed by diseases occurring in consequence of Venereal excesses_. It may be collected from later experience and observation that there are three clearly marked forms of the genius epidemicus or _epidemic condition_, that exercise a preponderating influence on affections of the genitals and Venereal disease, and condition the frequency of the occurrence of one or the other type of these, viz. _catarrhal_, conditioning blennorrhœal affections, the _exanthematic_, conditioning complaints of the cutaneous glands, and the _typhoïdal_, conditioning various forms of chancre and their malignancy.