240 THE SOCIAL LIFE OF ANIMALS 



people that London or Paris of the Middle Ages 

 afforded? 



A thoughtful and sincere biologist may object that 

 the world is too large an area for a successful co- 

 operative unit; that we need units intermediate in 

 size to allow for human evolution those advantages 

 which Professor Wright has demonstrated for popu- 

 lations intermediate in size. To such objection one 

 must reply that, as to the latter point, the main- 

 tenance of smaller co-operative and competing units 

 within the larger one is part of the scheme as 

 sketched. And to the first, that of the great size of 

 the earth, it needs only to be mentioned that thanks 

 to recent improvements in transportation facilities. 

 New York is in point of time as near the Orient as 

 it was to Los Angeles in 1885; and there are few 

 places on the globe as remote from Washington as 

 was San Francisco before the Union Pacific Railway 

 was built. In transportation and communication, and 

 in community of essential human interests, the world 

 is ripe for a workable international organization. 



From the standpoint of pure biology, disregarding 

 considerations that may seem to smack of the social 

 sciences, the mortal enemies of man are not his fel- 

 lows of another continent or race; they are the aspects 

 of the physical world which limit or challenge his 

 control, the disease germs that attack him and his 



