As to the several phases indicated in the title, there is no surprise at the development of xanthomatous characteristics in a zoster lesion since zoster is only one member of the list of diseases the sequelae of which may be fibrous; almost a dozen cases of "scar xanthomas" have already been described in the literature. Nevertheless, this additional illustration of the notorious propensity for xanthomatous infiltration to involve granulation tissue amplifies the knowledge of the conditions under which the infiltration can take place. It is thoroughly established that hypercholesterosis of itself will not guarantee xanthomatous infiltration even in the presence of pathologic fibrous tissue. There are an additional x and perhaps also y and z factors in the pathogenesis that remain to be sought out. Before one can generalize, one needs more and more data covering both the local and the general conditions under which xanthomas develop in scars, and