leukoderma colli of syphilis. This conception is like¬ wise entirely apart from the distinction made by the French authors concerning differences between leuko¬ derma and vitíligo. To them, if no hyperpigmented border is present, the condition should be called leuko¬ derma; but if a zone of hyperpigmentation surrounds the area of displaced pigment, the condition should be designated as vitíligo.On the other hand, the conception of leukoderma colli as clinically essentially different by reason of infil¬ tration, accompanied eruption, consistency and struc¬ ture of the skin has not been maintained.From time to time, both here and abroad, statistical papers have appeared giving the numerical percentages of co-appearance of clinical pigmentary dystrophies of the skin and serologie or historic syphilis, or even clinical syphilis. These are interesting and may be consulted.I have never subscribed, however, to the contention that syphilitic patients are more prone than other per¬ sons to present vitíligo or ordinary leukoderma. It is Fig. 2.-Melanoleukoderma colli: lesions extending to the .shoulders in male patient; the mottling is best seen on the dark patch.far fetched, in my opinion, to designate syphilis as.the etiologic factor in every patient with areas of depigmented skin. From the mass of cases, however, the leukomelanoderma or leukoderma colli, or so-called collar of Venus, stands apart as evidently associated with syphilis, and diagnostic of a syphilitic infection. The history of patients with leukoderma colli differs in no material respect from the history of patients of like age and sex who do not present the manifestation. I have not satisfied myself as to any possible associated etiologic condition either physiologic or pathologic. For the present, I will content myself with this ram¬ bling review of the present state of ignorance of con¬ ditions encountered in syphilitic patients.In passing, I will mention briefly the conditions that may require clinical differentiation from leukoderma colli :Chloasma, which is ordinarily found on the face, is infrequently the site of this type of pigmentary syphilid, and the mottling which is part of the characteristic picture of syphilid is absent. Chloasma is present in the older rather than the younger woman, who most frequently presents the melanoleukoderma of syphilis.Tinea versicolor, or pityriasis versicolor, is a scaly disease, as its name reveals, sometimes pruritic, and the organism described by Eichstedt (Microsporon furfur) may be demonstrated under the microscope.Vitíligo and leukoderma of nonsyphilitic patients is usually not symmetrical, and does not present the inter¬ mingling of the café au lait coloration. The question of the presence of vitíligo and leukoderma in syphilitic patients has been mentioned in the body of this paper.1The majority of authors who have written on the subject of diabetes mellitus agree that, in those cases in which diabetes is coexistent with syphilis, antisyphilitic treatment yields but little improvement of the diabetic condi...