One illustration, and a very striking one, of the influence of degeneracy on the brain is the durencephalous child which so often appears in degenerate families. Here the cerebral hemispheres and everything but the medulla and pons may be absent, while the rest of the body is in a comparatively normal state of development. Starting with such an extreme expression of degeneracy in the brain, a wide but closely linked range of deficiencies may be found in the brain of degenerates, involving even in some almost normal individuals more than simple deficiency. What was pointed out by Spitzka,[245] of New York, twenty years ago concerning the brain of hereditary lunatics, is equally true of the brains of the other degenerate branches of the same tree. The conventional notion associating idiocy and imbecility with quantitative deficiency of the forebrain only is, as Spitzka remarked, a very imperfect one. The researches of numerous observers have shown that qualitative defects (using the term qualitative in its wider sense to cover both morphologic and histologic aberrations) are as common, and are more characteristic features of the degenerate brain. These defects may be enumerated under the following heads: 1. Atypical asymmetry of the cerebral hemispheres as regards bulk. 2. Atypical asymmetry in the gyral development. 3. Persistence of embryonic features in the gyral arrangement. 4. Defective development of the great interhemispherical commisure. 5. Irregular and defective development of the great ganglia and of the conducting tracts. 6. Anomalies in the development of the minute elements or neurons (as the cells and associating of fibres are now generally called) of the brain. 7. Abnormal arrangements of the cerebral vascular channels. All of these conditions, separately or in the combination of several of the features above mentioned, are occasionally found in the brain of paranoiacs, moral imbeciles, criminals, deaf-mutes and other degenerates. Of the first type the brain (Fig. 111), from the practice of Kiernan, is an excellent illustration. This brain came from a paranoiac criminal who died in the Chicago (Cook County) Insane Hospital. A very similar brain was observed by Kiernan in one of the paranoiacs dying in the New York City Insane Hospital. Similar brains have been observed in deaf-mutes[246] whose mental status passed muster because of the allowance made for mental deficiency due to deaf-muteness. A brain showing as great asymmetry was found in the case of a French physician of standing who was a member of a mutual autopsy society. He proved, however, to have had degenerates in his ancestry and had exhibited peculiarities which showed that much of the degeneracy due to this ancestry had been corrected by proper training. The defects enumerated under Spitzka's second head are also observable in the illustration given. The gyres are not only asymmetrical as to their number in the two hemispheres, but also as to their size.