There is a great difference clinically between the effect of congenital and acquired lesions. When porencephaly (a deformity originally studied by Heschl) dates from infantile or foetal life, imbecility is always present during life; but where it is developed in the matured brain imbecility does not necessarily result. Deficiencies in the cerebral vascular system underlie the pathological phenomena on the basis of infantile cerebral paralysis, and allied hereditary and congenital states. The degenerate conditions in the spinal cord are essentially those described by Spitzka as occurring in the brain. Vascular states, either as to irregularities in the number of vessels or in the vessels themselves, underlie, as in the case of the cerebral palsies, hereditary ataxias and other congenital and hereditary spinal cord disorders.[251] CHAPTER XVII DEGENERACY OF MENTALITY AND MORALITY In the mental and moral degeneracies there is a complete transition from the durencephalic monster through the microcephalus, the idiot, the imbecile, and the feeble-minded to the mentally normal individual. Between the feeble-minded and the normal individual occurs a group whose general characteristics is, as was pointed out by Magnan, a disharmony and lack of equilibrium, not only between the intellectual operations, properly so-called on the one hand, and the emotions and propensities on the other, but even between the intellectual faculties themselves. A degenerate may be a scientist, an able lawyer, a great artist, a poet, a mathematician, a politician, a skilled administrator, and present from a moral standpoint profound defects, strange peculiarities and surprising lapses of conduct. As the moral element--the emotions and propensities--is the base of determination, it follows that these brilliant faculties are at the service of a bad cause, of the instincts and appetites which, thanks to the defects of the will, lead to very extravagant or very dangerous acts. In other cases the opposite occurs. Degenerates of irreproachable character show strange defects in their intellect. They often have a feeble memory in certain directions. Sometimes they cannot understand figures, or music, or drawing. In a word, an otherwise normal individual's intelligence is lacking as regards certain faculties. The centres of perception are unequally impressionable, unequally apt to gather together impressions, only certain impressions are registered and leave durable images; certain relations, certain associations between different centres, are perverted or even entirely destroyed.