78 FISSIROSTRES DIURNI. 



or damp weather perform their evohitions closer to 

 the ground, or they sometimes skim the sm^face of 

 lakes and rivers, in pursuit of their food, which 

 consists entirely of insects. They usually rest and 

 pass the night in a hole in some high building or 

 lofty tree, and in such places they also rear their 

 young. Their nest is composed of straw, and similar 

 materials, cemented together with a glutinous 

 secretion, furnished by certain glands that are 

 peculiar to birds of this sub-family. The eggs are 

 usually two in number. 



The Common Swift {Cypselus* apus) usually arrives 

 in Europe about tlie beginning of May. It leaves us 

 again generally about the middle of August, so that its 

 stay in Britain hardly exceeds three months. On the 

 continent of Africa these birds are seen as far south as 

 the Cape of Good Hope, but their proper whiter residence 

 appears to be between the tropics. Their migratory 

 instincts are truly wonderful. They will often return 

 after an absence of eight or nine months, and a voyage 

 of several thousand miles, to the very same spot where 

 they built their nests and reared their young the year 

 before. On its arrival, the Swift takes up its abode in 

 holes and other sheltered places, in church steeples, 

 towers, ruins, or under the eaves of houses. From these 

 nooks and corners it dashes forth in fine weather to 

 wheel about in the air with amazing rajiidity in pursuit 

 of insects, accompanying its headlong tiiglit with loud 

 screaming cries ; but when the day is unfavourable, and 

 es[)ecially when there is a high wind, the Swifts, not- 

 withstanding their power of wing, usually keep close 

 within their snug retreats. 



The voice of the Swift is not very pleasing. " He 

 has no roundelay ; he neither warbles nor carols, he does 

 not even twitter. His whole melody is a scream, un- 

 musical, but most joyous ; a squeak would be a better 

 name, but that, instead of conveying a notion that it 

 results fi'om jmin, it is full of rollicking delight. Some 

 compare it to the noise made by the sharpeidng of a saw : 

 to me it seems such an expression of pent-up joy as little 



* icvtpt\o(;, kupselos ; the Sand-Mar tin. 



