CHAPTER VI

CONSANGUINITY AND THE SPECIAL SENSES

United States Census Data--The Blind--Consanguinity of Parents--Blind Relatives--Degree of Blindness--Causes of Blindness--Retinitis Pigmentosa--European Data--Probability of Blind Offspring of Consanguineous Marriages--The Deaf--Irish Census--Scotland and Norway--United States Census--Consanguinity of Parents--Deaf Relatives--Causes of Deafness--Degree of Deafness--Direct Inheritance of Deafness--Intensification through Consanguinity--Dr. Fay's Statistics--Personal Data--Probability of Deaf Offspring from Consanguineous Marriages--Opinion of Dr. Bell