There is an aphorism to the effect that to know syphilis is to know medicine, and the physician is adjured, when in doubt, to suspect syphilis, since the extension of the disease is colossal. For example, the Wassermann reaction in Bellevue Hospital has yielded strongly positive results in over 25 per cent. of the enormous number of serums examined. This, of course, does not imply that one in every four persons is syphilitic, although in many instances, the reaction was carried out as a routine measure and not necessarily because contamination was suspected. The figure quoted indicates, nevertheless, that syphilis is even more widely distributed than is generally believed, assuming, of course, that the Wassermann reaction, as carried out with the cholesterin antigen, does not justify the skepticism with which it is received in certain quarters. On the other hand, among 4,880 necropsies performed at Bellevue Hospital in the past