Note: The patient’s sister, 4 years of age, is attractive and bright, measuring beyond her actual age according to the intelligence tests. However, the girl was found to have a positive W. R. It may be that Robert and his sister illustrate the hypothesis of Mott: that the syphilitic virus becomes less potent as the years go on, and that the younger children in the family are less affected than the older. However, in our series, there are a number of instances in which this hypothesis is not substantiated. 3. What is the share of syphilis in the production of feeblemindedness? The percentage of syphilitic cases found in institutions is not high. A variety of cases have been proved to be congenitally syphilitic in the absence of a positive serum W. R. Fernald[19] has charted a comparison of cases diagnosticated “moron” (that is, feeblemindedness proper, in the narrower English sense) and “imbecile.” Fernald says that the morons have, as a group, many more bad family histories than have the imbeciles, to quote—“Only 70% of the [imbecile] group have bad family histories. This at first seems surprising, but when we consider that more of our syphilitic, traumatic, and sporadic cases tend toward the lower end of the feebleminded group, and when we remember that with such cases there is often a seemingly normal family tree, the drop in the curve appears logical.” The situation with the idiots, of whom only 38 came into Fernald’s study, was similar; 12 out of 38, or 32%, of idiots, had good family histories. On these figures, how unfortunate it would be to dub feeblemindedness hereditary! It is true, however, that 68–70% of the idiots and imbeciles, judging by W. E. Fernald’s intensive study, do have bad family histories. Goddard[20] states that of all the causes of feeblemindedness, there is perhaps none for which there is less evidence than syphilis. Goddard found syphilis in 27 of his intensively charted cases of feeblemindedness, that is, in 9% of all his charts. He finds the majority of the syphilis cases occurring in relatives of the feebleminded to be in the hereditary group; for example, of 164 charts in the hereditary group, 17, or 10%, showed syphilis. In 34 charts in a group termed “probably hereditary” 3, or 9%, showed syphilis. Of 37 charts in the group termed “neuropathic” 4, or 11%, showed syphilis, whereas in 57 “accident” and 8 “no cause” groups, there were but 2 (4%), and one, or 13%, showing syphilis. However, Goddard concedes that much more careful studies are necessary if we are to give an exact evaluation of syphilogenic feeblemindedness.