x.] DISEASE. 169 



scope was unknown. They were then incompetent to 

 name diseases correctly. 



Mixture of Inheritances. The first thing that struck 

 me after methodically classifying the diseases of each 

 family, in the form shown in the Schedule, was their 

 great intermixture. The Tables A and B in Appendix Gl- 

 are offered as ordinary specimens of what is everywhere 

 to be found. They are actual cases, except that I have 

 given fancy names and initials, and for further conceal- 

 ment, have partially transposed the sexes. Imagine an 

 intermarriage between any two in the lower division of 

 these tables, and then consider the variety of inheritable 

 disease to which their children would be liable ! The 

 problem is rendered yet more complicated by the 

 metamorphoses of disease. The disease A in the parent 

 does not necessarily appear, even when inherited, as A in 

 the children. We know very little indeed about the 

 effect of a mixture of inheritable diseases, how far they 

 are mutually exclusive and how far they blend ; or how 

 far when they blend, they change into a third form. 

 Owing to the habit of free inter-marriage no person can 

 be exempt from the inheritance of a vast variety of 

 diseases or of special tendencies to them. Deaths by 

 mere old age and the accompanying failure of vital 

 powers without any well defined malady, are very 

 common in my collection, but I do not find as a rule, 

 that the children of persons who die of old age have any 

 marked immunity from specific diseases. 



There is a curious double appearance in the Records, 



