168 MARRIAGE AND DISEASE. 



offspring of that individual, we are justified in assuming 

 that some tendency to degeneration in the other parent 

 is the exciting cause of its reappearance. Therefore 

 we must suspect the in-coming parents who joined 

 the above family in its second and third genera- 

 tions of bearing some degenerate taint ; for had they 

 been free from taint, the deaf-mutism would have 

 been absent in the third, or certainly in the fourth 

 generation. The disease tendency in these in-coming 

 parents was not necessarily deaf-mutism. It may 

 have been scrofula, epilepsy, insanity, hereditary 

 syphilis, or any other depraved condition. All de- 

 generate characters are allied, and their promiscuous 

 mingling is slightly, if at all, less dangerous to 

 the offspring than the intermarriage of any one of 

 them. 



Sir William Turner says: "There can be little 

 doubt that congenital deaf-mutism, in the great 

 majority of instances, is associated with a defective 

 development ; " * and I think every one who studies 

 the subject will be of this opinion. Every person who 

 has visited an Institution for the deaf and dumb must 

 have been struck with the more or less imbecile aspect 

 of the unfortunate inmates. In the majority of deaf- 

 mutes, the whole economy, mental and bodily, is more 

 or less blighted. Many are scrofulous, and a vast 

 number succumb to phthisis. Physically they are 

 poorly developed ; they have round backs and narrow 



* Sir William Turner's Address at British Association, Newcastle, 

 1889. 



