The prominent facts which show the influence of the psychic state of the mother upon the somatic condition of the foetus explain the action of the imagination of the mother upon the development of the product of conception. The opinion which refers the origin of birth-marks to intense mental impressions on the part of the mother is not without physiological foundation. Concurrently with the motor phenomena, stigmata[81] may become developed by vascular and nutritive troubles produced under the influence of a strong excitation or by the imagination. Spitzka,[82] who approached maternal impressions from an actively sceptical standpoint, had his scepticism shaken by specimens (preserved in the British Museum) of newly hatched chicks, all of which had a curved beak like a parrot, and the toes set back as in that bird. According to the report of the curator the hens in the farmyard where these monstrosities were hatched had been frightened by a parrot which, having escaped, fluttered among them some time before the eggs were laid and greatly frightened those from whom the malformed chicks were received. It is certain that the chief argument of those who deny that maternal impressions are transmitted is defeated by this case. They have usually asserted that the explanation of the nature and cause of a birth-mark was always an after-thought on the part of the mother. But there was no after-thought in this case. The hens did not publish a theory as to the malformation of their chicks. It was their owner, a gentleman of intelligence and culture, who observed the casual occurrence, and who verified the almost photographic truthfulness of the germ monstrosity by depositing it in a museum as a permanent record at which none may cavil. Since then, the singular freaks attributable to maternal impressions of women, seen by Spitzka, have become so numerous that he has been compelled to negative the argument that they were merely accidental coincidences. He has never seen an idiotic, malformed child or one afflicted with morbid impulses derived from healthy parents free from hereditary taint in which a maternal impression could not be traced.