BOOK X.] History of Nature. 221 



of Birds more admirable than in this. The Hirundines 

 frame their Nests of Clay, but they strengthen them with 

 Straw. If at any Time there is a scarcity of Clay, they wet 

 their Feathers with a quantity of Water, and sprinkle the 

 Dust with it. They line the Nest itself with soft Feathers 

 or fine Flox, to keep the Eggs warm, and also that it may 

 not be hard to the young Birds. They distribute the Food 

 by turns to the Young with strict Equality. They remove 

 the Excrement of the young ones with remarkable Attention 

 to Cleanness ; but when they are grown something more, 

 they teach them to turn about, and discharge their Fulness 

 beyond it. 



There is another kind of Hirundo, that keeps in the 

 country Villages and Fields, which seldom build their Nests 

 in Houses ; but their Nests are formed of the same Material 

 as the former, although of a different Shape, supine, with the 

 Entrance thrust forward straight and narrow ; but "the Capa- 

 city within is large ; so that it is wonderful how skilful and 

 capable they are in concealing their young ones, and in 

 lining it with soft Materials. In the Heracleotic Mouth of 

 Egypt, there is a mighty Bank raised by a continual Course 

 of Nests for the length almost of one Stadium (half-a-quarter 

 of a Mile) ; which is impregnable against the spreading 

 abroad of the Nile : a piece of Work which could not have 

 been accomplished by human Labour. In the same Egypt, 

 near the Town Coptos, there is an Island sacred to Isis, 

 which, that the same River may not tear to Pieces, these 

 Swallows fortify by their Labour : in the beginning of the 

 Spring, for three Days and Nights, employing their Bill to 

 make it strong with Straw and Chaff; and they continue 

 their Work by Night with so much Labour, that it is 

 known many of them have died with the Labour. This 

 public Work always recurs to them with the return of the 

 Year. 



There is a third sort of these Swallows, which dig Hol- 

 lows in the Banks, and so form Nests within. The young 

 Birds of these, if burnt to Ashes, are a Remedy for the 

 deadly Quinsey, and many other Diseases of the human 



