24 PHYSICAL BASIS OF CIVILIZATION 



forced to take food oftener, and cannot uninterrupt- 

 edly sustain efforts for as long a period as his enemies 

 or competitors. This in an enormous disadvantage 

 in the struggle for existence. 



Fourthly, in the matter of multiplication, nature 

 has excessively discriminated against man, for the 

 period of pregnancy in our race is exceptionally long, 

 and the number of offspring born at one birth is as 

 low in our case as in any. 



Besides the above-mentioned deficiencies in nat- 

 ural endowment, man is afflicted with numerous 

 special infirmities, among which may be noticed the 

 absence of valves from the venae-cavas and from 

 the iliac, haemorrhoidal, and portal veins. Quad- 

 rupeds have no need of these valves in these blood- 

 vessels, but the lack of them in man produces fre- 

 quent cases of congestion, strangulation, illness, and 

 death. Many human beings are incapacitated an- 

 nually, or lose health and even life, by femoral and 

 inguinal hernias, appendicitis, varicocele, and vari- 

 cose veins, brought on and aggravated by the up- 

 right attitude. The frontal exposure of man's 

 femoral artery, produced by uprightness, annually 

 demands many victims, even in these days of medical 

 and surgical skill. In the primary ages of brute- 

 man's existence, the sacrifice of life from these causes 

 must have been enormous. 



The disadvantages above recited react with like 

 severity upon all specimens of the race, irrespective 

 of sex or age. Others must now be explained which 



