MINOR MASONS 3 



in his book on the "Ornithology of the Straits of 

 Gibraltar," was 9 in. long, 9 in. thick, and i\ in. 

 high. In this barrier there were no less than 282 

 stones. In the foundation of the nest were 76 more, 

 making 358 in all, of which the total weight was 

 4^ lb., the largest stone weighing 2 oz. It is difficult 

 to imagine how the little wheatear, intermediate in 

 size between a thrush and a robin, managed to carry 

 a stone of this weight. But perhaps it found this 

 particular pebble in situ. Having thus made the 

 foundation and wall of stone, it builds inside the 

 latter a comfortable nest, the upholstering of which 

 is in no way deficient in finish. The reason for this 

 hereditary taste for " overbuilding its position " may 

 perhaps be explained by a wish to improve the site 

 rather than the nest. Some other birds try to make 

 up for deficiencies in the position of the nest some- 

 what in the same way. The nuthatch, if the hole 

 leading to the place where it means to nest in a wall 

 or hollow tree is too large, will plaster the opening 

 up with a special cement, which becomes too hard 

 to be cut with a knife. In one case seen by the 

 writer the cement patch was as large as the hand, 

 though the hole left was no larger than a crown piece. 

 The nuthatch's ideal is a hollow dead branch, into 

 which it can bore just such a round hole. In this 

 case it made an artificial covering to part of the cavity, 

 and so reconstructed what was wanting. 



Sometimes a house-martin, another mason bird, 



instead of making a simple hole at the top of the 



si nest for an entrance, builds a kind of covered way 



