292 Heredity. 



the mental life, as, for instance, deaf-muteness, idiocy, and epilepsy. 

 In his view, consanguinity is of itself essentially baneful, and deter- 

 mines, without the concurrence of any other morbific cause, the 

 appearance of many grave diseases and infirmities. 1 



' History,' says Lucas, * witnesses to the disastrous consequences 

 which it brings on man.' * Aristocracies obliged to recruit their 

 numbers from among themselves become extinct,' says Niebuhr ; 

 'in the same way often passing through degeneracy, insanity, 

 dementia and imbecility.' Esquirol and Spurzheim, at least, give 

 this reason for the frequency of mental alienation and of its 

 heredity among the great families of France and England. Deaf- 

 muteness in humbler families appears also to have the same origin. 



It would not perhaps be rash to see an effect of consanguinity 

 in the premature decline of the Lagidse, and of the Seleucidce. 

 The Lagidse from Ptolemy Soter down to Cleopatra and Csesarion 

 ( 3 2 3 till 30) reckon sixteen sovereigns, and the Seleucidse, from 

 Seleucus Nicator to Antiochus Asiaticus ( 311 till 64) reckon 

 twenty. They often married their sisters, their nieces, or their aunts. 

 Moreover, when the marriages were not consanguineous, alliances 

 were formed between these two effete families, the Lagidse nearly 

 always marrying Seleucidae, and the Seleucidse marrying Lagidse. 

 Now, it is certain that these races were in a state of perpetual 

 decay, in proportion as they became more remote from their two 

 or three first founders. 



To these many reasons against consanguineous marriages 

 nothing but exceptional cases seem to be opposed. Burdach 

 attributes good results to consanguinity, but only among animals. 

 Dr. Bourgeois wrote the history of his own family, which was the 



1 Memoir de la Societe <f Anthropologie. According to Dr. Boudin, the danger 

 of consanguineous marriages is shown by the following facts. In Berlin there 

 were 



in 10,000 Catholics 3 deaf-mutes 



in 10,000 Protestants 6 



in 10,000 Jews 27 



In the United States, in 1840, the negro population, who were given to pro- 

 miscuity, showed in Iowa 91 times as many deaf-mutes as the whites. 



These figures, and the inferences drawn from them, have been questioned. 

 See Bulletins de la Soctit'e eP Anthropologie, vols. iii. and iv. 



