These observations upon a human child, two days old, unquestionably acephalous, i. e., absolutely without cerebrum, but as to the rest of its body not in the least abnormal, prove what I have already advanced (vol. i, p. 203), that the cerebrum takes no part at all in the first movements of the newly-born. In this respect the extremely rare case of an acephalous child, living for some days, supplies the place of an experiment of vivisection. Unfortunately, the child died so early that I could not carry on further observations and experiments. The report of the _post-mortem_ examination will be published by itself. Every observer of young children knows the great variety in the rapidity of their development, and will agree with me in general that a slow and steady development of the cerebral functions in the first four years, but especially in the first two years, justifies a more favorable prognosis than does a very hasty and unsteady development; but when during that period of time there occurs a complete and prolonged interruption of the mental development, then the danger is always great that the normal course will not be resumed. So much the more instructive, therefore, are the cases in which the children after such a standstill have come back to the normal condition. Four observations of this kind have been published by R. Demme ("19. Bericht ueber das Jenner'sche Kinderspital in Bern, 1882," S. 31 bis 52). These are of so great interest in their bearing on psychogenesis, and they confirm in so striking a manner some of the propositions laid down by me in this book, that I should like to print them here word for word, especially as the original does not appear to have found a wide circulation; but that would make my book altogether too large. I confine myself, therefore, to this reference, with the request that further cases of partial or total interruption of mental development during the first year of life, with a later progress in it, may be collected and made public. It is only in rare cases that microcephalous children can be observed, while living, for any considerable length of time continuously. In this respect a case described by Aeby is particularly instructive.