158 BRITISH AND EUROPEAN BIRDS. 



Yet at their first advent, on warm fanning- breeze, 

 They repose a long time on the summits of trees : 



The Esculenta, or Esculent Swallow, inhabits China and 

 the Islands of the Indian Ocean; it is only two inches and a 

 quarter long; blackish; beneath white; all the tail feathers 

 with a white spot; builds in caverns of rocks ; nest made of a 

 gelatinous substance, said to be obtained from marine plants, 

 but, most probably, a secretion from some gland in the bird 

 itself; it is eaten by the Asiatics as a luxury. Its chief ingre- 

 dient is doubtless gelatine. See the Introduction. 



The Urbica, Martin, House-Martin, Martlet, Martinet, is 

 bluish black, beneath white, tail feathers without spots; a va- 

 riety with quill and tail feathers tipt with white; five and a half 

 inches long ; builds under the eaves of houses ; the outside of 

 its nest like the common swallow, of clay; eggs white; inhabits 

 Europe and North America ; migrates like the swallow. See 

 the Introduction. 



The Apus, Swift, Black- Martin, Skir- Devil, or Skeer-Devil,* 

 is blackish, chin white ; eight inches long ; feet so small that it 

 rises from the ground, and walks with difficulty; is mostly on 

 the wing, and rests by clinging to some wall ; makes a harsh 

 disagreeable screaming ; builds chiefly in towers and other 

 lofty edifices. Arrives later than the common swallow. Re- 

 tires from England early in autumn. 



The Rufa inhabits Cayenne, is five and a half inches long ; 

 affixes its nest, which is sometimes a foot and a half long, to 

 beams. The Purpurea, or Purple Swallow, is entirely violet, 

 female brown ; inhabits Carolina and Virginia, where it is es- 

 teemed for its use as a warning to poultry of the approach of 

 birds of prey, which it becomes by attacking them furiously. 

 The Cayennensis, or White Collared Swift, is blackish 



* For the meaning of the term skir, see my Observations on 

 the Somerset Dialect, article To Skeer. 



