PHYSICAL DETERIORATION. 55 



to very consumptive families who escape the disease 

 by living under conditions where the bacillus tuber- 

 culosus is likely to be absent. On the other hand, 

 persons such as nurses are in all probability fre- 

 quently inhaling the microbe, and yet are not 

 attacked by the disease. In the first case immunity 

 is probably due to the absence of the seed, notwith- 

 standing the favourable condition of the soil ; in the 

 second it is due to the barrenness of the soil, not- 

 withstanding the presence of the seed." 



Inasmuch as phthisis is markedly hereditary, we 

 may look upon the type> not the disease, as being 

 transmitted. A phthisical type of person is one who 

 comes of a family liable to fall a prey to this mi- 

 crobe, and he is recognisable by many distinctive 

 characteristics of hair and complexion, and by quali- 

 ties of temperament, feature, and figure. 



Sufferers from phthisis are prone to other diseases, 

 such as pulmonary and bronchial attacks, so that 

 over and above the vulnerability to this one form of 

 microbe they are to be looked upon as unsuited not 

 only for the battle of life, but especially for parentage 

 and for the multiplication of the conditions from 

 which they themselves suffer. 



The phthisical are attractive in personal appear- 

 ance on account of their rich skin and hair colouring 

 and their frequent brightness and vivacity, and their 

 obvious delicacy also elicits a feeling of pity and 



