Spitzka has seen in practice, constitutionally melancholic or mentally defective children in whom no other predisposing cause could be discovered than that the mother was struggling with direct or indirect results of the financial crisis of 1873. In several of these cases the death of the father was a contributory cause of maternal depression. In Berlin the financial crisis of 1875-80 was followed by an increase in the number of idiots born. Lombroso attributes a series of cases of microcephaly to profound mental impressions occurring during pregnancy. To the same class of cases belong the hermaphrodites born by mothers who have been frightened in their first pregnancy and who continue to bear hermaphrodites. The continual and not ill-founded dread that the succeeding children may resemble the first is to be regarded as a contributory cause. Observers who have had a large experience with illegitimate births believe that the mental agony suffered by the unfortunate mother reacts upon the foetus, causing arrest of development, and thus accounting for the frequent occurrence of idiocy in illegitimate children. The influence of maternal diet on the foetus is excellently illustrated in the results of the "fruit diet" advised by certain vegetarians. Here the children[85] become, as Elise Berwig has recently shown, rickety, irritable, peevish, liable to convulsions, morally peculiar, and otherwise defective in contrast with children born of the same parents without "fruit diet" during pregnancy. Kiernan,[86] after citing instances reported by Amabile, Carson, F. B. Earle, Erlenmeyer, F. H. Hubbard, C. H. Hughes, Mattison, and others, of congenital opium habit where opium was needed to preserve the infant during the first months of life, states that inheritance of the opium habit seems at first an isolated phenomenon, but zoologists have pointed out that pigeons whose ancestors were fed on poppies became intractable to opium. Murrell found that the same was relatively true in England of persons descended from Bedfordshire ancestors who used infusions of poppies as a prophylactic against malaria. Nervous diseases were, however, relatively prevalent in these districts. Narcotic habits in the ancestors produces descendants in whom the normal checks on excessive nervous action are removed, so that paranoiacs, periodical lunatics, epileptics, hysterics, congenital criminals, congenital paupers, or other degenerates result. This influence is most strongly exerted when the maternal ancestor is the one affected, for to her is committed the development of the ovum prior to conception and of the child subsequently. If either is interfered with by a habit, a being defective in some respects is the result. The direct inheritance of the opium habit has been shown experimentally by Levenstein, who found by experiments on pregnant dogs and rabbits that the use of opium during pregnancy produced either abortion or still-births, or rapidly dying offspring.