Goitre and leprosy are the only endemic diseases; but the natives, being underfed, are prone to diarrhoea and dyspepsia.
Dr Twining, in the British Association Reports for 18 45, p. 79, cites some instances described by Humboldt, who says that the copper-coloured natives of the high plain of Bogoto, and at a lower level on the Magdalena river, were generally free from goitre.
The climate of Siberia, however, cannot be called unhealthy, except in certain localities where goitre is common, as it is on the Lena, in several valleys of Nerchinsk and in the Altai Mountains.
Professor POffig, also cited by Dr Twining, states that on the east side of the Andes in Chile, in some of the races which live there, he did not see a single case of goitre, and yet in the white inhabitants, who live exactly as the natives, it prevails in a great degree.
To-day their descendants are not more subject to goitre and cretinism than those dwelling around them, and are recognized by tradition and not by features or physical degeneracy.