514 PLINY'S NATUIU.L HISTORY. [BookX. 



soft feathers and wool, to keep the eggs warm, and in order 

 that the nest may not he 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 43 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 en trance 

 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 44 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. 



43 The first is the common chimney swallow. This latter one, Cuvier 

 says, is either the window swallow, the Hirundo urbica of Linnaeus, or else 

 the martinet, the Hirundo apus of Linnaeus. 



44 The bank swallow, or Hirundo riparia of Linnaous. 



