=The Mixed Chancre.=--Chancroid will now be described, and its consideration will include the statement that it may be followed by true syphilitic chancre. Such a lesion is known as _mixed chancre_ or _mixed sore_, and indicates a simultaneous infection by two distinct infecting agencies; it may easily cause confusion, for if seen early it will lack the characteristic induration of syphilis. This latter will only appear about the time that the chancroidal ulcers should be healed, if promptly and properly treated. Supposing this treatment to consist at least in part of caustics, the surgeon may be in doubt as to whether the induration is due to this agency or to developing syphilis. It seems justifiable to imagine causes of this kind while awaiting the further developments of the case, and to postpone vigorous antisyphilitic remedies until the diagnosis is established. It is a serious thing to condemn to a long course of mercurials a patient who perhaps does not need such drastic drugs. Instances arise where the situation is to be carefully considered in view of these possibilities. Should the healing and apparently healthy ulcer, however, take on an indurated base and develop the typical scleroses of chancre, it may be supposed that all doubt has been removed. The possibility of syphilitic infection being implanted upon a chancroidal base by subsequent exposure should also be taken into consideration. This will require an accurate history and a faithful narration of the same by the patient. There are, also, the _extragenital chancres_, which may be met with upon the hands, upon the breasts, in the oropharynx, as well as about the eyelids. Chancres on those surfaces of the body where tissues are loose may attain considerable size and ulcerate early, the discharge drying into scabs or crusts, which mask the underlying ulcer. Around the margins of the nails these lesions show but slight induration. Sometimes suppuration and granulation are profuse. When appearing upon the tonsils there is nearly always ulceration, with considerable swelling and often a false membrane. A patient with this lesion will complain of sore throat, and involvement of the surrounding lymphatics is usually extensive. When _chancre appears upon the lips_ there is usually extensive induration; the lesion attains considerable size, with protrusion, unless recognized and treated, and ulceration takes place early and deeply. It may be confused here with _epithelioma_. The latter occurs during the later period of life, is slower in its evolution, and its involvement of the neighboring lymph nodes. The local changes which often precede cancer, _e. g._, hyperkeratosis and papilloma, will be lacking in chancre of the lip.