Present and Prospective 197 



The second aim of preventive treatment — 

 thrown into the background now by the eager 

 quest of the microbe — is to obviate the predisposi- 

 tions or tendencies to disease which lie within the 

 organism. For such predisposition exists, whether 

 or not, disliking the word, we like to speak in- 

 stead of a constitutional soil suiting the microbe ; 

 facts not being changed by being named dif- 

 ferently, though men are very apt to think so. 

 Not to speak of the want of a full and exact study 

 of radically different types of constitution and of 

 their respective qualities and disease-tendencies, 

 of which little note has been taken since the 

 abandonment of the old doctrine of tempera- 

 ments, there is a strange want of any study of the 

 effects of the interbreeding of parental disease - 

 tendencies upon the constitution of the offspring. 



Might not some good come from systematic 

 inquiries into the production and elimination 

 of constitutional disease-tendencies and disease- 

 immunities by the marriage-unions of different 

 tendencies and immunities ? When a person has 

 a disease unlike that which either parent had he 

 may still owe it to them, variations occurring in 

 morbid heredity just as they do physiologically. 

 The case, of course, is not one of the breeding 

 together of actual diseases — no metaphysical con- 

 junction of morbid entities — but of two physical 

 organisms tending to go wrong in their respec- 

 tive ways. What is the morbid outcome of the 

 union of a phthisical and an insane diathesis ? 



