AN ESSA Y ON- LONGEVITY. 97 



ness in parentage, are equally remarkable for short 

 life. It is in this regard (influence of disease) that 

 the question of the average longevity or mortality of 

 groups of men ' to their potential longevity deserves 

 to b6 closely studied. At present, there are no data 

 to solve the question as to the extent or nature of 

 the influence of the one over the cither, and an ex- 

 amination of the various life-tables given below shews 

 that the relation is most inconstant (see p. 109 et seq.). 

 We may almost look upon excessively injurious 

 conditions of existence and their effect on individuals 

 as a definite thing comparable to a disease, being just 

 as abnormal as in contrast with the most healthy state 

 known to us ; and we may say that no man with the 

 disease 'Fuegian,' or 'Esquimaux,' or 'Australian,'^ 

 would have as fair a chance of long life, however 

 favourable his circumstances, with that exception, as 

 -the man who does not labour under the disadvantage 

 of a long ancestry of degraded savagery, and is there- 

 fore free from such disease ; just as we have no hesi- 

 tation in saying that a man with hereditary phthisis, 

 scrofulous, or cancerous tendency, has not so fair a 

 chance of long life as the healthy man. And just as 

 in the course of a few generations the offspring of the 

 latter may become quite healthy, so may the offspring 

 of the former, in so far as his hereditary tendency to 

 short life is concerned.^ 



1 Or we may add, ' English mechanic,' or ' poverty and dirt.' 

 " Mr. Hendriks, of the Universal Life Office, informed the writer that 

 H 



