184 PHYSICAL INVESTIGATION. [PART I. 



dren are frequently stunted and deficient in vitality this, at 

 least, is the prevailing belief in that country. 1 



Some of these cases remind us of the axiom of Buffon, that, 

 from the connexion of near relations, morbid affections, idiotcy, 

 blindness, and dumbness arise. It does not yet seem to be 

 ascertained how it stands with regard to domestic animals. In 

 the breeding of blood horses the stallion is made to cover his 

 own descendants. On the other hand, it is asserted that all 

 races of animals are entirely deteriorated in the second and 

 third generation by the coupling of near relations ; and such is 

 also the case with man. 2 We know that in many ancient and mo- 

 dern nations, marriages between brothers and sisters, even be- 

 tween parents and their children, frequently took place without 

 a deterioration of the race. Such alliances were made among 

 the Assyrians, Egyptians, Athenians, Persians, some peoples of 

 India (before, and even after, the introduction of Buddhism), 

 the Druses, Mingrelians, the royal family of the Sandwich 

 Islands. This also appears from some legends of American 

 Indians and other nations. Garcilasso 3 narrates that the chil- 

 dren of Manco Capac intermarried, and that this was the custom 

 in the royal family of Peru, to keep the race pure. They jus- 

 tified the custom, inasmuch as the moon was both the sister 

 and the wife of the sun. The Inca always married his eldest 

 sister. According to Acosta, 4 only the last Incas did so. 

 Among the Coroados marriages between the nearest blood 

 relations occur frequently. 5 As proofs of the destructiveness 

 of such connexions, the Irish in South Carolina are cited, who 

 for a long time have only intermarried between themselves. 6 

 The Dutch colonists at the Cape are in the same condition ; 7 

 Lichtenstein 8 had already noticed the frequent presence among 

 them of deaf and dumb, idiots, etc. Davis 9 says also of the so- 



1 Kohl in Ausland, p. 57, 1859. 



2 Lucas, ii, p. 904. 



3 " Hist, des Yncas," i, pp. 2, 25. 



4 " Hist. nat. e morale delle Indie/' vi, c. 12, Venet., 1596. 



5 Eschwege, " Journal v. Brasil," i, p. 121, 1818. 



6 Nott and Gliddon, p. 408. 



7 Kretschmar, " Siid-Afr. Skizzen," p. 163, 1853. 



8 " Reisen," i, pp. 101, 211, 346. 



9 "El Gringo," p. 146, N. York, 1857. 



