It remains for me in the present article to show that hereditary influence is as clearly marked in mental aptitudes as in general intellectual power. I will then enter into some of the considerations which my views on hereditary talent and character naturally suggest. I will first quote a few of those cases in which characteristics have been inherited that clearly depend on peculiarities of organization. It is distinctly shown by him, and agreed to by others, such as Mr G. Lewes, that predisposition to any form of disease, or any malformation, may become an inheritance.
General maladies are equally inheritable, as gout and madness.
Longevity on the one hand, and premature deaths on the other, go by descent. If we consider a class of peculiarities, more recondite in their origin than these, we shall still find the law of inheritance to hold good. A morbid susceptibility to contagious disease, or to the poisonous effects of opium, or of calomel, and an aversion to the taste of meat, are all found to be inherited. So is a craving for drink, or for gambling, strong sexual passion, a proclivity to pauperism, to crimes of violence, and to crimes of fraud. There are certain marked types of character, justly associated with marked types of feature and of temperament.