66 THE DISPERSAL OF SHELLS. 



these animals, it seems necessary to inquire as to their 

 flying habitSj and I have tried, but without much 

 success, to ascertain how often they take wing, whether 

 they are in the habit of making long flights, etc. Canon 

 Fowler, of whom I inquired, is inclined to think that 

 Dytiscij as a rule, do not take to flight unless their pools 

 are drying up, his impression being that they simply 

 fly when driven by necessity, and then make for near 

 water ; and if such be the case it is obvious, of course, 

 that the facts concerning them just referred to have 

 but little significance. But on the other hand, Mr. 

 Darwin ^ ventured to observe that " the species of 

 Dytiscus often fly at night," and indeed he had several 

 times heard of their having dashed down upon glass 

 cucumber-frames, mistaking the glittering surface for 

 water, and Mr. Norgate informs me that he has actually 

 seen the insects upon the glass of such frames. A 

 specimen of D, marginalis once flew into a shop in Hull, 

 and from the nature of the locality, it is probable that it 

 had travelled some distance." Mr. Standen states that he 

 has several times caught the creatures on the wing when 

 out moth-hunting after dusk in the evening,^ and Mr. 

 Musson tells me that he has taken large water-beetles 

 at the electric light in the main street of Tamworth, 

 New South Wales, It is unfortunate that more definite 

 information is not forthcoming, but I believe we may 

 conclude that these beetles journey from pond to pond 



' "Nature," xxv. (1882), 529-30. 



' E. Lamplough, '* Science Gossip," xxiii. (1887), 19. 



' R. Standen, " Nat. Hist. Notes," iii. (1883), 39. 



