=Evolution of the Disease.=--Ever since the days of Ricord’s writings on the subject it has been customary to group the manifestations of syphilis into three groups or stages: _the primary_, _the secondary_, _and the tertiary_. Less stress is laid upon these stages than previously, yet it is convenient to retain them for descriptive purposes. It should be emphasized, however, that between them there are no arbitrary limits of time or tissue. _Primary_ syphilis under this classification includes the first period of incubation and the symptoms and appearances of the initial lesions. _Secondary_ syphilis may be made to include the earlier constitutional symptoms which involve or at least become apparent upon the more superficial portions of the body, _i. e._, skin, mucous membrane, lymphatics, etc. Later comes the so-called _tertiary_ period, in which the body surfaces are not necessarily spared, but in which also deep lesions of the viscera, the bones, the brain, etc., are noted. Between the first and the second stages comes the so-called second period of incubation. The second and third stages are characterized by frequent neoplastic formations, which assume the type of the infectious granulomas and are commonly spoken of as gummas; these lesions are destructive in their tendency, and will so prove unless dissipated or aborted by suitable treatment. _In the first and second stages of the disease it can be conveyed by inheritance and inoculation_; in the later stage such an occurrence is exceptional. That syphilis is, _per se_, an infection is proved by the constitutional symptoms which accompany its earlier manifestations; the fever, usually mild, though sometimes well marked, which comes early in the course of the disease, the general lymphatic involvement, the malaise and depression, all indicate the systemic disturbances of a true toxemia. The periods of quiescence between successive outbreaks of the disease are, moreover, characteristic, although they sometimes lull the patient and his physician into an inactive state, during which medication is too often suspended, so that when fresh disturbance arises vigorous treatment must be renewed. _The infection of syphilis occurs on the instant of inoculation_, as in the case of tetanus. This is important, as upon it depends the question of early local treatment. While excision of the primary sore, or even of an area which might have become infected during exposure, and before the actual formation of the chancre, has been often practised and urged by some, experience has shown that it has little to commend it, since the general experience is that it does not prevent the development of the disease.