XXIX. 



THE DEPARTURE OF THE SWIFTS. 



THE earliest among all our summer migrants to leave 

 us for warmer autumn quarters are those large, dark, 

 rapid swallows, known best to country people as black 

 martins or jack-screamers, but to which ornithologists 

 have given the very appropriate name of swifts. They 

 coine in spring a week or ten days later than their con- 

 geners about the 25th of April in an average year and 

 they are all gone again by the first week in August, only 

 a very rare straggler being ever seen in England after the 

 middle of the month. Even in Southern Europe they 

 do not linger into September. No other bird except 

 their ally, the humming-bird is so ceaselessly active on 

 its wings as the swift. Popular science (or what once 

 passed for such) has told the same story about it as about 

 the bird of paradise : that it had no feet, and so was 

 compelled to keep forever on the wing except when 

 in its nest ; and the fable has even been enshrined by 

 more rigid biologists in its systematic name of Cypselus 

 opus. On early summer evenings you may see the 

 swifts skimming the surface of still pools on their broad 

 wings, catching the May -flies and dragon-flies that hover 

 above the edge, and sometimes just dipping below the 

 level in their curved sweep to take a flying sip from the 

 water as they go. Their monotonous shrill scream never 

 ceases for a moment meanwhile ; for the swift appears 

 to be all nerve and muscle a sort of miniature engine 

 for perpetual motion, self-feeding and self-governing, 



