28 AMID THE HIGH HILLS 
excepting courtship flight, which is usually of an 
accelerated nature." 
To quote the words of Major C. R. E. Rad- 
clyfFe : ^ " The only possible test we can accept 
is where two birds are matched one against the 
other, and we are certain they are both trying 
their hardest. No better test than this is the case 
of a hawk pursuing its quarry, when it means to 
one of them its food and to the other its life." 
The same writer draws attention to a common 
fallacy : "It is," he says,^ " purely a matter of 
optical illusion to imagine that a smaller-sized bird 
is flying faster than a larger bird of similar shape 
and make ; for example, a snipe on rising ground 
seems to go much faster than a woodcock, simi- 
larly a teal than a duck, and possibly this may be 
so for a short distance, but put up the first two 
together, and also the last two, and let there be a 
peregrine after them — as I have seen many times 
— and the scene is amazing to a man who is not a 
falconer, as the smaller bird is overhauled first 
every time by the falcon, and presumably they 
are all trying their hardest. ... I have dozens of 
times put up a peregrine over ponds and marshes 
where teal and ducks were sitting together, and 
1 Field, February 18, 1922, p. 231.. 
