The _movements of the eyes_ are interfered with by lesions which pertain, however, rather to the brain and the ocular nerves than to the eye itself. The sixth nerve, lying on the floor of the skull, is affected by syphilitic disease at the base of the bone. As a result of these nerve lesions paralysis is often seen, or at least disturbances of motility from which _diplopia_ results. _Ptosis_ occurs from affection of the third nerve. In lesions situated below the aqueduct of Sylvius, the paralytic condition which Hutchinson has spoken of as _ophthalmoplegia_ is likely to appear. _Optic neuritis_ is also a late manifestation of syphilis, and may be either chronic and mild, with a small disturbance of vision, or acute, with rapid loss of eyesight. =The Ear.=--The ear may suffer in various ways. The external ear may participate in affections of the adjoining skin. The middle ear may be affected as a result of extension of trouble from the nasopharynx, while in the late stages of the disease patients may suffer from labyrinthine disease, with partial or almost total deafness. =The Nose.=--The lesions of syphilis in the nose are numerous and offensive. Ulceration is frequent and followed by perforation through the septum or into the mouth. When the vomer is involved the bridge of the nose falls in. In neglected cases the whole substance of the nose may be involved and subsequently lost. The bone is often exfoliated. These ulcerations of the mucous membrane and periosteum give rise to a characteristic condition known as _ozena_, with its characteristic discharge. =The Oropharynx.=--The tongue may be the site of intermediate and late syphilitic lesions. Men suffer more than women, apparently because of their use of tobacco. Mucous patches, deep ulcers, and even gummas, single or multiple, are seen here. Gummas in the tongue are inclined to undergo superficial ulcerative infection and become abscesses. In these lesions there will be notable involvement of the adjoining lymphatics. The appearance of smooth, bluish-gray patches upon the mucous membrane of the tongue and cheeks is known as _leukoplakia_ or _leukokeratosis_. These lesions do not respond readily to treatment; they give rise to little or no complaint, and are often followed by malignant disease. It is difficult to distinguish between gumma of the tongue and epithelioma. Usually the latter is a single lesion; the former often multiple. In epithelioma the ulcer is superficially painful, with more elevated and indurated edges, while the pain is sometimes intense and radiates toward the ears. _Interstitial glossitis_ is a late manifestation of a sclerosis beginning in the connective tissue and involving the muscle fibers, leading to enlargement of the tongue and later to atrophy and inflexibility.