This paper is based principally on a series of 149 cases of ophthalmia neonatorum under my charge in the contagion wards of the Massachusetts Charitable Eye and Ear Infirmary, between Aug. 1, 1913, and Oct. 1, 1914. It is not presented primarily, however, as a statistical study, or as a consideration of the whole subject of ophthalmia neonatorum, but rather of those aspects of the disease which have appealed especially to me and about some of which there is yet considerable difference of opinion. In addition, attempt has been made to bring the sociological aspect of the disease into close relationship with the clinical side. HOSPITAL OR HOME TREATMENT In the first place, is a baby with a severe ophthalmia neonatorum best treated in the home or in the hospital? The obvious answer is, at the hospital, if we exclude those cases occurring in well-to-do families in which it is