SWAN UPPING 



197 



(although this is liable, of course, to variation), and 

 the proportion of old to young birds : — 



Here it will be seen that in the lower reaches of 

 the river there were comparatively few swans, that 

 their numbers increased in proportion as they 

 escaped from the traffic of boats and warehouses, 

 and that they were most numerous between Bray 

 and Henley. 



