94 The Building of the Nest 



into a gimlet for the time, and uses its beak 

 as the point of the tool. This is odd work 

 for a bird that almost lives in the air ; and 

 then think, too, of sitting in a dark cave, 

 sometimes six feet long, until the eggs are 

 hatched. On the other hand, the barn swal- 

 low makes a nest where there is plenty of 

 light and air, and is a mason rather than a 

 carpenter or miner. The mud he uses is 

 not mere earth and water, but is made more 

 adherent by a trace of secretion from the 

 bird's mouth ; at least, my experiments lead 

 me to think so. To build such a nest would 

 be slow work did not the two birds work 

 together and carry their little loads of mortar 

 with great rapidity. They waste no time, 

 and use only good materials, for I have 

 noticed them, when building, go to a quite 

 distant spot for the mud when a pool was 

 direftly outside of the barn in which they 

 were building. To all appearance the nest 

 is of sun-dried mud, but the material has cer- 

 tainly undergone a kind of puddling first that 

 makes it more adherent, bit to bit, and the 

 whole to the rafter or side of the building. 

 Again, these swallows have the knack of 

 carrying a little water on the feathers of 



