but on the left arm where vasogen iodine had been rubbed in there was decided improvement, the lesions being pale, less scaly, and there was some clearance as compared with the right side, which had not been treated. I did not see her again until February 7th, 1905, and she then told me that the improvement where the X-rays had been applied had continued, and in a few weeks after I last saw her, in August, 1904, the disease had entirely disappeared from the outer side of the leg below the knee, and the skin when I examined it was quite white and smooth on the part exposed and had been so for four months, while the inner side of the leg where the rays had not reached remained unaltered. She had not continued the vasogen iodine to the arm, and it had become scaly again. General Remarks on the Disease. From the above description and the cases related in support of it, what inference may be drawn as to the nature of the disease and its relation to other skin affections? Frankly, at present I am quite unable to even conjecture its pathology, or to suggest, with one exception, any relation to other dermatoses. In my first cases I supposed that it was an early stage of Mycosis fungoides, though the absence or trifling character of the subjective symptoms did not lend this any support. I clung to this theory, however, _faute de mieux_, for a long time, but it received its _coup de grace_ when I met with a case of over thirty years’ duration without any such malign development. At the Dermatological Society of London, where Mr. George Pernet and myself have shown three cases, among other suggestions, that of a possible seborrhoïde or Urticaria pigmentosa have been made. Against the former, the absence of scaliness in a large proportion of the patches, that the patches are in the skin, not raised above, and that itching is an exceptional feature, together with the unchanging character of the lesions, effectually bar the diagnosis of a seborrhoïde. Neither can I find anything beyond the yellowish tint frequently, but not always, present to support the idea of Urticaria pigmentosa. The absence of itching in nearly all the cases of Urticaria factitia, while the patches are level with the normal skin, and their unchanging character, are all strongly against such a diagnosis, to say nothing of the extreme rarity of adult Urticaria pigmentosa and the improbability of one man meeting with nine cases of it. The histology also negatives this. I can therefore, at present, only regard it as a dermatosis _sui-generis_, of which the pathology must be left an open question, as Mr. George Pernet’s report on the histology of the portion of skin removed from Case 8 does not throw much light upon the pathology. There remains only the affection described by Brocq, to which, certainly, there are closer resemblances than to any other affection. Brocq[1] divides the group which he calls parapsoriasis into three groups: