THE EAVES-SWALLOW. 211 



more difficult to build against than the ordinary rough struc- 

 ture. The eaves, too, were at right angles. If we make some 

 diagrams we can see what shape would be best fitted for these 

 conditions and for the old style of barn. Under sloping, 

 unfinished eaves the bottle nest does not tit well ; a pocket is 

 better. But under square-finished eaves the flask-shaped nest, 

 with slight modification, fits perfectly. When we recollect that 

 mud does not stick to smooth paint very well, we shall see that 

 under eaves of this sort the bottle nest gives a greater support- 

 ing surface than the pocket. The nest is stronger for being 

 of that shape. It is more work to make it, but the work pays 

 in the end. Whether these swallows built their nests so 

 because they were wise, or because they did not know any 

 better, we cannot tell; but we shall see that they are still 

 capable of making improvements and of adapting themselves 

 to varying circumstances. 



The bottle-nosed nest is not entirely gone yet. There has 

 been a revival of it in a colony near my home within a few 

 years. When this colony grew so large that it found its favor- 

 ite barn too small, there was a great demand for nesting-places 

 among the swallows, and much ingenuity was shown in building 

 on badly shaped house-lots. This is an old-fashioned barn with 

 sloping rafters, unfinished beneath. The nests not only follow 

 the side of the barn close beneath the eaves, but they extend 

 down both sides of the rafters, and are placed in tiers one 

 below the other, clinging partly to the wall and i)artly to the 

 nests above. The lowest nests, that is, those nearest the edge 

 of the eaves, are most exposed to the weather, and these are 

 often built with bottle necks. The nests built first are not of 

 this type because the birds take the most desirable places and 

 build the nest requiring least work. But, later in the season, 

 the bottle necks ai^pear. 



