THE SEA SWALLOW 21 
that many parents remained in possession of their 
proper offspring. 
There are other occasions, too, greater catas- 
trophes by far, which must entail amongst the 
old birds the keenest of competition for surviving 
nestlings. In these disasters, too, parentage is 
probably settled by Solomon’s law. They are 
consequent on conditions to which littoral species 
are increasingly subject. Almost everywhere sea- 
fowl breeding about river estuaries have been 
ousted by progress of settlement from naturally 
secure sites. In the one particular instance about 
which I write, the harm was done in little more 
than an hour. Although calm and fine locally, 
a gale evidently had been blowing outside. A 
heavy sea began late one afternoon to thunder » 
and pound on the beach, and to force an immense 
weight of water into the lagoon. With the flow 
of the tide it was a miserable sight to watch the 
Ternery. With the advancing flood the lowest 
nests were soon engulfed. As the water still 
continued to rise, first dozens of sitting birds 
and then hundreds were flooded off their nests, 
the egg-pits filled, and the eggs rolled about 
and floated away. In some cases the birds sat 
until actually raised by the water, whilst eggs 
and drowning chicks were everywhere adrift. It 
was a bit of mere good fortune, a sudden lucky 
lull that, together with the turn of the tide, saved 
