130 The Irish Naturalist. July, 



Barn Owl to be the cause, unless a newly-reared family 

 lived in the immediate neighbourhood ; and their being so 

 frequently seen agrees little with the theory tendered by 

 the Shropshire and Norfolk witnesses that the luminosity 

 is an effect of ill health. Luminous insects, although it is 

 probable that some occur in Ireland, are nearly placed out 

 of court by the December date of so many of the observa- 

 tions ; and it also seems difficult to suggest that any other 

 species of bird, even though it might have been carrying or 

 have come in contact with decaying and phosphorescent 

 substances, is more likely than an owl to have produced 

 the appearance described. 



It is worth inquiring whether the hypothesis of an ignis 

 fatuus is out of the question. This phenomenon is so 

 generally pictured as "dancing" and " flickering " about 

 marshy land that one does not think of it as performing 

 steady journeys over regular beats like those described in 

 the communications before us. These descriptions, however, 

 strongly recalled to the present writer an account given 

 him by Mr. E. C. Barrington of the movements of a 

 " Willy-the-Wisp " which apparently frequents the Dona- 

 bate estuary with some regularity during suitable nights in 

 late autumn. Mr. Barrington has, accordingly, been applied 

 to for a short description of the phenomenon in question, 

 and has written in reply as follows : — 



" During the months of November and December, 

 sometimes in January, while duck-shooting on the mud- 

 flats round Donabate estuary, I have frequently observed 

 Willy-the-Wisp. The light on many occasions was very 

 bright, and would travel at a considerable speed over wet 

 ground, going out and reappearing some little distance off. 

 It would often retrace its steps, and more than once I have 

 seen it patrolling the same beat for upwards of half -an - 

 hour. All the nights I have visited this locality there was 

 a slight moon or full moon with cloudy sky ; I admit it 

 was when the moon retired I saw it most. On one or two 

 occasions I saw it travel over very deep mud and against 

 the wind, when it would come to a certain shape and Hare 

 up and go out, reappearing at intervals, like a liame, and 

 then retire. Many natives round that district have seen 



