The differential diagnosis involves consideration of the characteristics of the insane, defective, and epileptic. We repeat that we agree that the mentally abnormal person may engage in pathological lying quite apart from any expression of delusions, and that during the course of such lying the insanity may not be recognized. This occurred in many of the cases cited in the foreign literature, and if the prior histories of many individuals now in insane hospitals were known undoubtedly such lying would be frequently noted. But once the person is recognized as insane he need not be classified as a pathological liar. This term should be reserved, as we stated previously, for normal individuals who engage in pathological lying. Of course other observers have noted such lying in people who could not be designated as being mentally abnormal, but our material is peculiarly rich in examples of this kind. CORRELATIONS STUDIED FOR CAUSES Heredity. We come now to a very interesting group of facts--showing at once complete corroboration of previous observers' statements that pathological liars are extraordinarily ``erbliche belastet.'' Taking our 19 mentally normal cases we find the following: Insanity in the direct family (four of these being a parent). .6 One or both parents severely alcoholic. . . . . . . . . . . . .6 Criminal or very dissolute parent . . . . . . . . . . . . . . .4 Suicide of parent . . . . . . . . . . . . . . . . . . . . . . .1 Extremely neuropathic parent. . . . . . . . . . . . . . . . . .1 Syphilitic parent . . . . . . . . . . . . . . . . . . . . . . .2 Epileptic parent. . . . . . . . . . . . . . . . . . . . . . . .1 Unsatisfactory data . . . . . . . . . . . . . . . . . . . . . .2 Reliable data showing normal family stock . . . . . . . . . . .2 Thus, out of the 19 cases there are only three or four which do not come of stock showing striking defects. Now, as we go on to show later that unfortunate conditions or experiences were often causal factors, the total findings seem to show clearly that these latter influences generally bore their unfortunate fruition upon inherited instability. The heredity in the border-line cases is, as might be expected, even worse. These facts are easily discerned in their respective case histories.