Insects, 4199 



Apion seneum, F. Portmavnock. Apion rainiatum, Schbn. Malahide, &c. 



„ Carduorum, Kby. Local. „ subulatum, Kby. Not common. 



„ rufirostre, F. Ditto. „ vorax, Hbst. Ditto. 



„ virens, Hbst. Portmarnock, abun- „ Eivi, Kby. Ditto. 



dant. „ assimile, Ste. Local. 



„ Kirbii, Ste. Phoenix Park. Ramphus flavicornis, Civ. Phoenix Park, 



„ flavipes, F. Local. on hawthorn. 



„ nigritarse, Kby. Ditto. Rhynchites Alliaria?, Pk. Taken by Mr. 



„ apricans, Hbst. Not un frequent. Tardy. 



„ Pisi, F. Local. „ Betulae, L. Ditto. 



(To be continued). 



A. R. Hogan. 



Charlton, Dundrum, near Dublin, 

 January, 1854. 



The Cholera Fly. — Something has been said at the meetings of almost every Na- 

 tural-History Society, on a small fly (Aphis Rumicis), which appeared in vast swarms 

 during the past autumn, in those districts of the North of England which have been 

 stricken with that fearful scourge, the cholera. No notice has, I believe, been previ- 

 ously taken of the occurrence of this fly at the time when the cholera has been raging ; 

 I therefore think that the following may be interesting. In 1833, when this plague 

 was at its height in Exeter, the very same thing happened. As I was then only just 

 out of my long clothes, my own entomological recollections will not carry me so far ; 

 but years and years ago my mother has told me that at that time vast swarms of very 

 minute flies suddenly passed over the city like misty clouds, and darkened the air, even 

 in the brightest sunshine. On these occasions, any meat that might be exposed in the 

 air, became immediately putrid. My mother, on seeing these clouds approach, always 

 ordered the windows to be closed ; and by that means, she believed, kept off the cho- 

 lera from the house. Whether this fly has anything to do with the cause of the dis- 

 ease ; whether it always accompanies the malaria without being the direct cause ; or 

 whether it be simply an accidental circumstance resulting from the favourable state 

 of the atmosphere at the time for their development, are questions which further ob- 

 servation, or, at any rate, heads wiser than mine must decide. At the same time, I 

 will just observe, that if the fly be the cause of the cholera, the diminution of the dis- 

 ease, which has always taken place during the winter months, would in a great mea- 

 sure be accounted for, since the insects would then be destroyed by the cold ; while if, 

 on the contrary, cholera were caused solely by noxious vapours proceeding from insuf- 

 ficient drainage &c, I think that that evil would be rather aggravated than otherwise, 

 at a time when the weight of the atmosphere prevents those gaseous particles from 

 dispersing. Again, can any one say what is the origin of cholera ? Alas ! they can- 

 not ; if they could, we might hope that some remedy would be found. Whatever be 

 its origin, it must be agreed that it is some ingredient of the atmosphere, borne along 

 with greater or less rapidity through whole countries or continents. Wherever cho- 

 lera breaks out, some foreign nucleus has been imported into the district, the develope- 

 ment of which is of greater or less extent, depending on certain secondary conditions, 



