On the Wheat Fly. 323 



many learned men forbids my speaking positively on this sub- 

 ject, but I cannot agree with your correspondent, that " there 

 can be no doubt that the colouring matter of the famous red 

 snow, brought from the arctic regions by Captain Ross and 

 Captain Parry is a true vegetable." There is still a doubt, 

 and until this doubt is removed, I would suggest that the tri- 

 vial name of the Protococcus nivalis should be changed to that 

 first adopted by Agardh, namely, Protococcus kermesinus. 



I have seen nothing in any work that I have had access to 

 that could subvert the opinion that I have now advanced. If 

 I recollect aright, Wollaston declared that during combustion 

 it emitted the odour of burnt animal substances. The micro- 

 scopic observations of Bauer and Agardh prove nothing since 

 those of Brown have been made known ; and indeed Professor 

 Agardh concludes his Memoir on the subject with a doubt, 

 whether, after all, the colouring matter of the red snow may 

 not be of animal nature; whilst your correspondent mentions 

 that Nees Von Esenbeck was inclined to think that the minute 

 red globules were the vegetable state of bodies that had gone 

 through a prior animal existence. The specimen examined 

 by Dr. Greville was procured from the Island of Lismore, 

 and, of course, may be quite a different thing. 



I shall conclude by hoping that if any of your readers 

 should ever make £^ voyage to Baffin's Bay, that he will not 

 fail to procure a portion of the red snow, and of the dung of the 

 Little Auks, or Cockroaches (as they are called by our Greenland 

 seamen), for further examination. I am, Sir, &c. 



Antigua, May 28. 1829. Thos. Nicholson. 



I 



Art. IV. On ike Wheat Fly. By Mr. Archibald Gorrie, 

 C.M.H.S., &c. 



Sir, 

 In September, 1828, I submitted to your readers a query 

 concerning the wheat fly, which appeared in the Magazine of 

 Natural History (Vol. II. p. 292). At that time I did not know 

 that a yellow fly had deposited the eggs within the glume, 

 which became maggots. Observing numbers of black flies on 

 the ears of wheat, I believed they had been the produce of 

 the caterpillar; and, as will appear by my query, I supposed 

 they deposited their eggs about the grain. I have this season, 

 however, observed the yellow fly (described by the Rev. W. 

 Kirby in Vol. I. p. 227.) deposit its eggs in the wheat ear, 

 and, what is remarkable, in the ear of the Triticum repens, 



