60 
PEOFESSOE K. PEAESON ON THE INFLUENCE OF NATUEAI 
In the diagram Ave have also drawn the contour line to which the French jiopulation 
must extend if we are to get at least a representative population of 1000 Aino from 
it, and further the contour line to which the Aino population must extend if we are 
to get at least a representative population of 1000 French from it. A consideration of 
