514 
pliny's natueal history. 
[Book X, 
soft feathers and wool, to keep the eggs warm, and in order 
that the nest may not be hard and rough to its young when 
hatched. It divides the food among its offspring with the 
most rigid justice, giving it first to one and then to another. 
With a remarkable notion of cleanliness, it throws out of the 
nest the ordure of the young ones, and when they have grown 
a little older, teaches them how to turn round, and let it fall 
outside of the nest. 
There is another kind of swallow, also, that frequents the 
fields and the country ; its nest is of a different shape, though 
of the same materials, but it rarely builds it against houses. 
The nest has its mouth turned straight upwards, and the entrance 
to it is long and narrow, while the body is very capacious. It 
is quite wonderful what skill is displayed in the formation of 
it, for the purpose of concealing the young ones, and of pre- 
senting a soft surface for them to lie upon. At the Heracleotic 
Mouth of the Nile in Egypt, the swallows present an insu- 
perable obstacle to the inroads of that river, in the embank- 
ment which is formed by their nests in one continuous line, 
nearly a stadium in length ; a thing that could not possibly 
have been effected by the agency of man. In Egypt, too, 
near the city of Coptos, there is an island sacred to Isis. In 
the early days of spring, the swallows strengthen the an- 
gular corner of this island with chaff and straw, thus forti- 
fying it in order that the river may not sweep it away. This 
work they persevere in for three days and nights together, with 
such unremitting labour, that it is a well-known fact that 
many of them die with their exertions. This, too, is a toil 
which recurs regularly for them every year. 
There is, again, a third kind^* of swallow, which makes holes 
in the banks of rivers, to serve for its nest. The young of 
these birds, reduced to ashes, are a good specific against mortal 
maladies of the throat, and tend to cure many other diseases of 
the human body. These birds do not build nests, and they take 
care to migrate a good many days before, if it so happens that 
the rise of the river is about to reach their holes. 
^3 The first is the common chimney swallow. This latter one, Cuvier 
says, is either the window swallow, the Hirundo urbica of Linneeus, or else 
the martinet, the Hirnndo apus of Linnaeus. 
The bank swallow, or Hirundo riparia of Linnaeus. 
