Remarks upon the Theory of Hybridity. 357 



in the beginning of October, about ten o'clock. To an en- 

 quiry whether he thought the motion of the object he saw, 

 especially when it divided, and played about, and then united 

 again, was like anything he had seen before, he replied that he 

 did not know ; but, when afterwards asked if he thought it like 

 the playing of flies or gnats in the sun, he said it was precisely 

 similar. The spot where he saw it was shown to me. The 

 soil is dry, and the situation is slightly elevated above the sur- 

 rounding country : there is no marshy or swampy ground in 

 the neighbourhood. The man's name is William Day. He 

 was brought up in my father's family, and resides there still. 

 I have questioned many persons who have seen the Ignis 

 Fatuus, besides those whom I have mentioned, and they in- 

 variably concur in its having a voluntary motion, flying back- 

 wards and forwards, rising to clear hedges, resting on gates, 

 pales, and other objects that lie in its route. From the facts 

 I have been able to collect, I think we may infer that many 

 more insects are luminous than naturalists have imagined ; 

 and, should these observations not be sufficient to convince 

 naturalists that the supposed Ignes Fatui are really and truly 

 insects, yet I anxiously hope that the remarks I have made 

 may be the means of leading gentlemen, who reside in favour- 

 able situations, to investigate this curious phenomenon. 



[There undoubtedly appear considerable grounds for sup- 

 posing that the history of many cases of Ignes Fatui may be 

 connected with the light emitted by certain insects ; but, at 

 the same time, there is strong evidence opposed to the univer- 

 sal adoption of this explanation. For observations on this 

 subject, see Jameson's Edinburgh Journal for January, 1833, 

 and Entomological Magazine^ vol. i. p. 350. — Ed.} 



Art. IV. Some Remarks upon the Theory of Hybridity, By 

 Thomas C. Eyton, Esq., F.Z.S. 



At the last meeting of the British Association, held at 

 Bristol, I mentioned, during a discussion on the subject, that 

 a hybrid male and female, derived from the Chinese and com- 

 mon goose*, had been productive inter se. 



This fact appeared, at the time, to be doubted by some gen- 



* It has been conjectured that the common goose of our farm-yards 

 may have been derived from the snow goose (A. hyperboreus Li?i.)> chiefly 

 on account of the old males being white. There is also a white variety 

 of the Chinese, with the red eyes of the albino. The bill of the snow 

 goose differs, also, much in form from that of our common sort ; on which 

 account I think this not likely. 



DD 3 



