TRANSMISSION OF CHARACTERISTICS 89 



mission in a latent form, although the fact may be 

 apt to escape notice. Such complaints as deafness and 

 dumbness may certainly skip a generation or two. Of 

 this there is an example in the records of the lunacy 

 commissioners of Scotland. A deaf mute man mar- 

 ried a woman of normal faculties, and by her had two 

 children, namely, a deaf mute son, who died childless, 

 and an apparently sound daughter, who married a 

 sound man. This woman had two daughters and a 

 son. In the daughters their grandfather's infirmity 

 reappeared. The son escaped it, and married a sound 

 woman. But liis son was a deaf mute, inheriting 

 thus the infirmity of a great-grandfather. 



Transmitted disease is perhaps more liable to 

 break out in the children who most resemble the 

 affected parent, but this is not a universal rule. Sir 

 Thomas Watson says in his King's College Lectures : 

 " I am acquainted with a gentleman who has lost 

 several brothers and sisters by phthisis. The fatal 

 disposition is known to exist on his mother's side, 

 while his father's is believed to be quite free from it. 

 All the children who have hitherto become con- 

 sumptive have resembled the mother in bodily con- 

 figuration and features, except this gentleman, who is 

 like his father's family, but who nevertheless labours 



