BANK SWALLOW. 599 



The holes are formed at the top of a quarry merely because 

 that is the only place where the materials are soft enough for 

 the purpose. In a shallow sand-pit I have seen some so low as 

 to be reached by the hand, and a few not at a greater height than 

 four feet. In another pit, they were scattered about the middle, 

 where there was less coarse gravel. Frequently, on the other 

 hand, when bored in the soil, they are within two feet or even 

 less of the surface. Now, certainly, had these birds reason, it 

 would be very thoughtless or foolish in them to deposit their 

 nests so frequently in places where they can be so easily reach- 

 ed by boys and others ; but as they have merely the boring 

 instinct, they exercise their propensity without reflection. Mul- 

 titudes of their nests are destroyed every year by workmen who 

 break down the sides of sand-pits, and boys who dig them out. 



The flight of the Bank Swallow is light, graceful, flickering, 

 and rapid. White remarks that it has " a peculiar manner of 

 flying, flitting about with odd jerks and vacillations, not unlike 

 the motions of a butterfly," and doubtless there is some resem- 

 blance ; but the other species exhibit the same motions, although 

 with more freedom as it were, or on a larger scale. It is to be 

 seen flying about chiefly in the vicinity of its nest, but also over 

 meadows, pools, and rivers, and in all varieties of low situations, 

 in which the insects that form its food abound. I have not 

 found sand or gravel in the stomach of this species, more than 

 in that of the others. Its mouth is equally bedewed with a 

 viscid saliva. Some writers, observing this copious secretion 

 in the mouths of swallows, and seeing the mud crusts of their 

 nests pretty firmly compacted, have alleged that they employ it 

 as a cement. Others have even gone so far as to assert that 

 the Java Swallow forms its esculent nests of this viscous mat- 

 ter. I have failed in discovering traces of glutinous or albu- 

 minous matter in the nests of our White-rumped and Red- 

 fronted Swallows ; that of the Sand Swallow can have no pre- 

 tension to any ; and as many birds, such as Goatsuckers and 

 Sylviae, which do not form concrete nests, have an equally 

 abundant saliva, I cannot but consider the notion as totally 

 unfounded. How many theories, generalizations, and alleged 

 facts, in Natural History, have turned out to be baseless, rash, 

 or inauthentic ! 



