2 20 ANIMALS OF LAND AND SEA 



flashing iridescence of the peacock's tail or of certain pheasants' 



plumes. 



The dazzling iridescence of the plumage of many tropical 

 birds such as some of the more brilliant pheasants and the birds 

 of paradise was long thought to indicate that light was given 

 out, and hence that these brilhant creatures were luminous at 



night. 



From the very earliest days in Europe the people have from 

 time to time been frightened by the appearance of night-fly- 

 ing birds which as they passed gave out a steady glowing 

 light. There were very many guesses as to what these lumi- 

 nous birds could be. A common idea was that they were the 

 blue roller, Europe's handsomest bird, which with its glossy 

 plumage looks as if it ought to give forth light at night. But 

 they are really barn-owls with their breast feathers apparently 

 smeared with a luminous fungus rubbed off the decaying wood 

 about the hole which serves as their retreat by day. 



In England this phenomenon has been studied very carefuUy. 

 As a t>pical example of the appearance of such birds I quote 

 the following from the ornithological report for Norfolk for 

 1907, by Mr. J. H. Gurney. 



"February 3rd. — A luminous Barn-Owl, emitting such bril- 

 liancy as to resemble a distant carriage-lamp, was seen at 

 Twyford by Mr. R. J. Purdy and other persons. It was, 

 however, not until December that the existence of a pair of 

 these luminous birds attracted general notice, attention being 

 directed to this phenomenon by Sir T. Digby Pigott in 'The 

 Times.' 



"December ist. — The luminous Barn-Owl which, except for 

 one appearance to Mr. Spencer in October, had not been seen 

 since February, was again observed by Mr. R. J. Purdy, his 

 son, and other persons, shining brightly in the same locaUty as 

 before. 



"December 22nd. — ^Again the luminous Owl showed itself 

 to Mr. Purdy, and between this date and the 29th it was seen 

 by several people, and by many others subsequently. On the 



