62 THE TREND OF THE RACE 



stances to fall victims to insanity. Not improbably the very 

 large number of cases in which the mating of normal and 

 feeble-minded produce children of the latter class are due not so 

 much to the heterozygous character of the putative normals as to 

 partial blending, or irregular and incomplete dominance. As our 

 previous discussion has shown, where one parent is feeble-minded 

 or insane, and the other normal, it is quite exceptional for all the 

 children to be free from the mental taint of the afflicted parent. 



SYPHILIS AND MENTAL DEFECT 



The role of syphilis in the causation of feeble-mindedness, 

 epilepsy, and other forms of mental defect is still uncertain, 

 despite a considerable amount of investigation devoted to the 

 subject. Formerly syphilis was not considered to be accountable 

 for a large percentage of mental defect, because only a small 

 proportion of defectives were found to manifest any obvious signs 

 of the disease. Since the discovery of the Wassermann and other 

 tests it has been possible to detect syphilitic infection in numerous 

 cases in which the disease was not revealed by any external 

 symptoms. The Wassermann test, however, is apt to give very 

 different results according to the particular way in which it is 

 carried out. It is agreed that the absence of the positive Wasser- 

 mann does not necessarily indicate the absence of syphilis, but a 

 positive test except in the presence of a few other diseases or 

 unusual conditions is held to constitute a strong proof that 

 syphilis is present. Applications of the Wassermann tests to 

 mental defectives have yielded surprisingly discrepant results. 

 Goddard, in his work on feeble-mindedness, states that less than 

 I per cent show syphilitic infection. Thomson, Boas, Hjort 

 and Leschly in studying 2,061 mental defectives found that only 

 1.5 per cent gave a positive Wassermann reaction. Lippmann 

 found 9 per cent of positive reactions in one asylum, and 13 per 

 cent in another. Dean found that out of 330 idiots of various 

 ages in Potsdam 15 per cent were syphilitic. Krober obtained 

 positive results in 21.4 per cent of 262 idiots.^ 



1 Reference may also be made to the work of Atwood and Brofenbrenner who by 



