NATURAL HISTORY OF SELBORNK. 155 



and destroy their nests ; but instances are also remembered 

 where they bred for many years in vast abundance in a hot 

 stifled inn-yard against a wall facing to the south. 



Birds in general are wise in their choice of situation ; but 

 in this neighbourhood every summer is seen a strong proof 

 to the contrary at a house without eaves in an exposed 

 district, where some martins build year by year in the 

 corners of the windows. But, as the corners of these 

 windows (which face to the south-east and south-west) are 

 too shallow, the nests are washed down every hard rain 

 and yet these birds drudge on to no purpose, from summer 

 to summer, without changing their aspect or house. It is 

 a piteous sight to see them labouring when half their nest 

 is washed away and bringing dirt. . . . "generis lapsi 

 sarcire ruinas." Thus is instinct a most wonderful unequal 

 faculty ; in some instances so much above reason, in other 

 respects so far below it ! Martins love to frequent towns, 

 especially if there are great lakes and rivers at hand ; nay, 

 they even affect the close air of London. And I have not 

 only seen them nesting in the borough, but even in the 

 Strand and Fleet Street ; but then it was obvious from the 

 dinginess of their aspect that their feathers partook of the 

 filth of that sooty atmosphere. Martins are by far the 

 least agile of the four species ; their wings and tails are 

 short, and therefore they are not capable of such surprising 

 turns and quick and glancing evolutions as the swallow, 

 Accordingly they make use of a placid easy motion in a 

 middle region of the air, seldom mounting to any great 

 height, and never sweeping long together over the surface 

 of the ground or water. They do not wander far for food, 

 but affect sheltered districts, over some lake, or under some 

 hanging wood, or in some hollow vale, especially in windy 

 weather. They breed the latest of all the swallow kind : 



