From my study of this subject I have been led to form the following conclusions:- (1) That Phlyctenular kerato-conjunctivitis is essentially a disease of children; the greatest incidence occurring between the ages of three and five years. It may occur for the first time in those of adult age, but much more often in adults one finds that an attack is really a recurrence of a condition which has been carried on from childhood or adolescence. (2) That girls are more susceptible to the infection than boys; the proportions being eight girl3 to every five boys. Recurrences in adults are much more prevalent in the female sex. (3) That this form of conjunctival inflammation is not of Tubercular origin. It may, however, coexist with tubercular lesions elsewhere in the body. Results obtained by the ¥on Pirquet Tuberculin test would seem to indicate the presence of Tuberculosis in the vast majority of cases. That such is the case, is not borne out by clinical study. (4) That the patients have inherited a peculiar type Ox constitutional defect, of which perhaps the most obvious symptoms are associated with (a) an inability on the part of the digestion to cope with certain of the constituents of a normal" diet. (b) A certain hyper-sensitiveness of the epiblastic tissues. (5) That in addition to the aforesaid predisposition there is a definite toxin at work, which is probably specific in its action, and is responsible for the production of the phlyctenular inflammatory process. ' From this it may be gathered that the .writer holds the view that the condition is not exogenous in origin. (6) That all children possessed of this particular constitution or diathesis do not of necessity show symptoms of Phlyctenular disease in the eye. There may be an apparent concentration of the predisposition in connexion with the gastrointestinal functions, in which case the eyes may not become the seat of obvious symptoms. In other cases the inherited weakness seems to be concentrated upon the epithelial tissues and in these cases the eyes are very constantly involved. (7) That there is close relationship between the eczematous condition of the skin and the ocular manifestations. It is probable that the etiological factors are the same for both. (8) That there is a considerable variation in the degree of the inherent susceptibility, and this factor together with the effect produced upon the health by environment, dieting and general hygiene, is responsible for the time of onset of the symptoms of Phlyctenular ophthalmia. (9) That very frequently it happens that in large families only one member may develop this form of eye trouble. In those oases it is usually the youngest or one of the younger members who are so affected. (10) That the state of nutrition of the mother during pregnancy and while nursing is of vital importanc in determining the incidence of the diathesis. (11) That little importance is attached to the exanthemata as etiological factors. (12) That not all children who have inherited this lowered immunity to infection possess the grosser facial stigmata (e.g. lack of development of the nasal bones and hyperplasia of the upper lip, etc.) so characteristic of the diathesis. Many children however with typical facies do not suffer from phlyctenular disease. They are of course of the constitution nevertheless. (13) That in a proportion of the children there is a disturbance in the balance between the various glands of the endocrine system. In others there appears to be a generalised hyperplasia of the lymphoid tissue. (14) That in cases where recurrences continue over long periods of time and especially in those which extend into adult life, there is invariably present some obvious co-existing debilitating factor. This may take the form of Pyorrhoea; necrosis of the teeth; refractive errors; chronic inflammation of the Tonsils; in appropriate dieting; bad hygienic conditions; unsuitable occupation, etc. (15) That phlyctenular disease is preventable. (16) That the importance of intensive preventive measures should be brought to the notice of the Public Health, Educational and Municipal Authorities. (17) That treatment with Ultra Violet Light is proving to be of infinite value. It enables children to have the benefit of rays to which they have but little access in the ordinary course of events. As a substitute for exposure to the sun Ultra Violet Light increases the resisting/ resisting powers to infection, mobilising the vitamins present in the body in such a way that use may be obtained from quantities which must otherwise have been too small. (18) That a properly balanced diet, with a sufficiency of vitamin content, and regularity in the observance of meal hours, are essentials in treatment.