374 THE HUMAN SPECIES 



and that this is undoubtedly proved by the advances made 

 during the last century, and especially during its latter half. 

 During the twentieth century we shall make still further dis- 

 coveries in the heavens and on the earth ; we shall make still 

 more improvements in the construction of our machines and in 

 the conditions of life. But the struggle for existence, which even 

 now is fierce enough, will become still more determined owing 

 to the increase in the population ; whether in the course of 

 future ages it will be possible for the body to keep pace with 

 the feverish activity of the brain is a very open question. 



I am far from asserting, as does R. Arndt, that all genius, 

 and even talent, or superior endowment of any kind, is a sign 

 of degeneration. It cannot, however, be denied that civilisation 

 itself, especially in its most advanced form, carries with it 

 certain risks to the minds and bodies of men. At the present 

 time it is no secret that the increase in cases of neurasthenia, 

 insanity and suicide must be attributed to the struggle for 

 existence, especially when the harassed brain has been spurred 

 on by alcohol, as so frequently happens. In civilised races we 

 often see increase in intellectual power go hand in hand with 

 a narrowing of the jaw and an early loss of the teeth ; in men 

 premature baldness, and in women inability to suckle their 

 children. In both sexes we find imperfect development of the 

 thorax, and consequent predisposition to tuberculous disease of 

 the lungs. In the third part of this work we shall deal with 

 the pathological changes peculiar to man, as well as with those 

 which he exhibits in common with other animals. 



It is impossible to foresee whether hygienic efforts will be 

 able to keep pace with the knowledge of these risks, and so 

 be ever more and more able to ward off degeneration from 

 civilised peoples. Instead of prophesying an unlimited advance 

 for mankind through future ages, it would seem more rational 

 to withhold our judgment, as does Branco, for " when we rashly 

 attempt to explore the future, we find, instead of an answer to 

 our questions, that a bandage is laid across our eyes ". 



