28 



KAEL PEAESON 



Table Y. Ordinates of Infiltration Curve over straight Boundary. 



n = oo is used to denote the Rayleigh solution. 



This table suggests some interesting points. The curves for n = 6 and n = 7 are 

 fairly close together, but differ sensibly from the Rayleigh solution, perhaps 

 4 or 5 per cent., where the density is at all material. For many practical 

 purposes this might be close enough, and we see that for infiltration as distinct 

 from dispersal curves, the Rayleigh solution — owing to integration over an area 

 — gives fairly close results. The greatest percentage deviations from the Rayleigh 

 solution are to be found in the tail. Now no individual can be found beyond 

 the range nl from the boundary, and cr — J^nl; thus the maximum range is J'Zncr, 

 or, for n = 6 and 7, the maximum range is 3'46o- and 3"74<r respectively. The 

 <u-function expansion brings this out well. For w = 6 at 3 "40- there is not one in 

 100,000 individuals, while the Rayleigh solution gives 34. For n = 7 there are 

 still 4 in the 100,000, because we are a little distance still from the limit of 



