164 HEREDITY IN RELATION TO EUGENICS 



the air. The dry, dusty and often germ laden air is a diffi- 

 culty with which our mucous membranes can hardly grapple; 



little wonder that they, and the 

 whole body, so often succumb. 



Of the diseases of the lungs the 

 most fatal is tuberculosis. We 

 know that it is induced by a germ 

 and that if there is no germ there 

 will be no tuberculosis of the 



Fig. 142.-Pedigree of heart l^^g^. The first Impulse of the 



trouble. The father's father, I, modern sanitarian is to eliminate 



1, died of anguina pectoris at 69 , t> j. j.i • • 



years; and the mother's father, I, the germ. ±5ut thlS IS a SUpra- 



3 died of ossification ofthevalves herculean task: for germs of tu- 



of the heart at 59. Father and . . 



mother are living and said to be berculosis are found in all cities 



d^fd of hea^ileS-J "ntS ^^ ^ *^« ^^^^^ry amongst most 

 and another, III, 2, had tempo- domesticated animals. The 



rary heart trouble. F. R.: All. 1. t,- -x i j_i 



germs are ubiquitous; how then 

 shall any escape? Why do only 10 per cent die from the 

 attacks of this parasite? 



I ta^ hfo 



s. 6^MffiSSif^ 



Fig. 143. — Pedigree of family with heart disease and migraine, I, 2, died 

 of heart disease at 72 years; II, 2, 4, 7, died of "heart disease;" II, 9, died of 

 "heart failure" at 59 years, hardworking physician; III, 1, suffers from mi- 

 graine; her mother is a semi-invalid from migraine. F. R.; Bra, 1. 



The answer is given by autopsies and the experiences of 

 many physicians. Autopsies show that nearly all mature per- 

 sons have the germs of tuberculosis in their lungs, but, for 

 most part encysted and, perhaps, even completely destroyed. 



