22 BIRD LIFE ON ISLAND AND SHORE 
the majority of the nests; the sea happened to 
go down as rapidly as it had risen. Five hundred 
eggs or tiny chicks had nevertheless perished. 
Another hour would have seen the last of at least 
fifteen hundred more, two thousand that is, out 
of twenty-five hundred eggs and chicks in the 
particular Ternery affected. 
The Sea Swallow tribe well exemplify the general 
truth that amongst creatures below man in the 
scale of creation there is that lack of adaptability, 
that powerlessness to deal with any sudden new 
situation, which marks the limit of instinctive 
action. The simplest of experiments with a sit- 
ting Tern showed the bird nonplussed by con- 
ditions outside the range of experience, outside 
that hard-set knowledge of the ages, primarily in 
the bird’s frame, but reinforced and corroborated 
in each successive generation. I found that the 
removal of the egg three inches away from the 
egg-pit left the poor owner helpless before a vast 
insoluble other-world conundrum, a conundrum as 
of Mars or the moon. As it lay smooth and allur- 
ing on the warm sand she did not attempt to sit 
on it, to touch it, to scoop the sand from beneath 
it and thus create a new nest, or to roll it into its 
proper hollow. Watching it always as if fasci- 
nated, she merely ran up and down, circling about 
its vicinity in an agitated manner. I then replaced 
the egg, its owner being allowed to incubate the 
