THE DESCENT OR ORIGIN OF MAN 185 



for long periods, so that they canaot freely transmit their 

 bad qualities. Melancholic and insane persons are confined 

 or commit suicide. Violent and quarrelsome men often 

 come to a bloody end. The restless who will not follow 

 any steady occupation — and this relic of barbarism is a great 

 check to civilization" — emigrate to newly settled countries, 

 where they prove useful pioneers. Intemperance is so highly 

 destructive, that the expectation of life of the intemperate, 

 at the age of thirty for instance, is only 13.8 years; while 

 for the rural laborers of England at the same age it is 40.59 

 years." Profligate women bear few children, and profligate 

 men rarely marry ; both suffer from disease. In the breed- 

 ing of domestic animals, the elimination of those individuals, 

 though few in number, which are in any marked manner in- 

 ferior, is by no means an unimportant element toward suc- 

 cess. This especially holds good with injurious characters 

 which tend to reappear through reversion, such as blackness 

 in sheep ; and with mankind some of the worst dispositions, 

 which occasionally without any assignable cause make their 

 appearance in families, may perhaps be reversions to a sav- 

 age state, from which we are not removed by very many 

 generations. This view seems indeed recognized in the 

 common expression that such mea are the black sheep 

 of the family. 



With civilized nations, as far as an advanced standard 

 of morality and an increased number of fairly good men 

 are concerned, natural selection apparently effects but little; 

 though the fundamental social instincts were originally thus 

 gained. But I have already, said enough, while treating of 

 the lower races, on the causes which lead to the advance 

 of morality, namely, the approbation of our fellow-men— 

 the strengthening of our sympathies by habit — example 



" "Hereditary Genius," 1810, p. 34'r. 



'^ B. Eay Lankester, "Comparative Longevity," IStO, p. 115. The labia 

 of the intemperate ia from Neison's "Vital Statistics." In regard to profligacy, 

 see Dr. Farr, "Influence of Marriage on Mortality," "Nat. Assoc, .for the 

 Promotion of Social Science," 1858. 



