Gall is apt to be judged, very unjustly, only by his errors; for he was, in truth, the originator of the principle of the localization of the functions of the brain, and gave the first impulse to the scientific study of criminals, though he did not himself make any definite discoveries in this field. His pupil, Lauvergne, prison surgeon at Toulon during a long period of years, examined thousands of criminals, and left interesting plaster-casts of skulls; certain types were admirably described by him. Despine made a thorough study of the psychology of the criminal, and showed that the principal characteristics of the habitual criminal are idleness, irresolution, and lessened sensibility, both mental and physical. Supplementary to Despine’s investigations was the great work of Lucas upon heredity, in which he demonstrated the hereditary transmissibility of the disposition to theft, murder, rape, and arson, and furnished extensive materials regarding the congenital nature of the tendency to crime. Morel’s work lacked thorough analysis, and was also destitute of a firm biological foundation; but it was based upon extensive materials, and was animated by a certain instinct for what was important. His “Traité des Dégénérescences” was published in 1859. Thus originated the catchword “degeneration,” which remains current to-day, without having even yet acquired any definite signification. Now it is used to denote the neuropathic constitution; now, again, to denote the hereditary predisposition to psychoses. According to some this predisposition is latent, and manifests itself only by physical stigmata of degeneration; others regard the degenerate as being mentally as well as physically abnormal, and as suffering, either before the onset of actual insanity or in the entire absence of the latter from mutability of mood and temper, obsessive ideas, moral defects, and one-sided intellectual endowment; yet others use the term “degeneration” to denote a vague diathesis—a mingling of tendencies to disturbances of metabolism and to neuropathies. More recent French investigators distinguish between “higher” and “lower” degenerates, and include in these categories almost the entire province of mental disturbances, severe neuroses, and criminality. German investigators go so far as to explain that most human beings are degenerates, and Moebius held that the repulsiveness of the majority of his fellow-creatures spoke in favour of this view.