LUMINOUS BIRDS AND OTHER ANIMALS. 113 



seemed suffused with a dark oily substance. The feathers 

 of the powder-down patches did not burn more readily than 

 feathers from other parts, and the odor was the same. 



These patches are not strictly confined to cranes and 

 herons. The kirumbo (or Leptosmus discolor) of Madagascar 

 has a highly developed patch upon each side of the rump. 

 These birds are related to the rollers, and are remarkable 

 for their games in mid-air. The bitterns have two pairs of 

 powder-down patches, the true herons three, and the curious 

 boatbills (Cochlearius') four pairs, which, if all luminous, 

 must render them the centre of attraction in the South- 

 American swamps. 



The interesting oil-bird Podargus (or Guarcharo), that 

 builds in the island of Trinidad and on various parts of the 

 South-American coast, is a fruit-eating, nocturnal bird allied 

 to the night-hawks. Curiously enough, it has no oil-glands, 

 but two large powder-down patches, one on each side of 

 the rump, composed, according to Dr. Sclater, "who made the 

 discovery, of about forty feathers each. In Plate XXVIL, 

 an ideal view is given of the possible appearance of the 

 light of a large heron (Ardeomega goliath) of Africa. 



Whether these lights are of sufficient brightness to 

 attract fishes is a question ; but, knowing that fishes are 

 readily attracted by light of fire, we may well imagine that 

 a crane or heron, if standing in the water in perfect stillness, 

 with this soft light a short distance above it, might possibly 

 avail itself of such a lure, though such a view is purely con- 

 jectural. Mr. Charles Harris of Pasadena, Cal., informed me 

 that several years ago he entered a heronry in Maine on a 

 dark night, and distinctly observed numbers of lights too 

 large for insects ; and, moreover, they disappeared with the 



