I HAVE called this a Memorandum for several reasons. The actual case histories are imperfect, while the ancestry beyond the parents is unobtainable. All that can be said is that the parents have no knowledge of serious defect in their forbears. I may add by way of excuse for imperfections that all the children were seen in the course of a routine school ophthalmic clinic where time and oppor-tunity for investigation and consultation with colleagues are limited. There are two outstanding facts.(1) The mother has eight living children and had two mishaps. All the surviving children were born in abnormal presentations and in each case there was rather severe post-partum haemorrhage. Of the eight living children four are boys and four are girls. Of these the four boys are affected. The four girls are definitely reported to be normal sighted. The only girl examined by me was normal except for low myopia. Had any of the other three girls suffered from defective vision they would, in the ordinary course, have been referred to me by the School Medical Officer. Indeed the mother would have brought them of her own accord, had she observed any defect. She was so positive, however, that they were perfectly normal that she seemed unwilling to have them examined, and the point was not pressed.(2) The second principal fact is that the four boys all had a peculiar macular condition with varying degrees of affection of the opftic nerve, while, in one case (Thomas), chronic retinal disease eventually led to retinal detachment in both eyes and toa cicatrix in or near one macula. In this case the unfortunate position has been reached that while the patient is unfitted for anything except very simple employment he has been refused certification as a blind person" within the meaning of the Act." The three oldest boys have been under observation, more or less, since 1920 when they were seen consecutively. The fourth came to notice rather later (in 1926) and is probably the most typical as regards the macular appearances. In two of the boys (Thomas being one of them) Dr. Forgan, County VD Officer, reported a negative Wassermann reaction. One of the boys (Thomas) is reported to have had" fits" in infancy. Nothing else has been discovered of any importance, but complete scientific investigations have not been possible.