4^6 THE WHEAT-FLY. 



shire, which threatened much mischief. Some of 

 the ears were brought to him for examination ; 

 and, on opening those that seemed diseased, he 

 found in many an orange-coloured powder, and in 

 several one or two very minute larvae of a yellow 

 colour. On applying a magnifier, for they were 

 too minute for examination with the naked eye, he 

 supposed them at that time to be the larvae of a 

 small species of Musca; but they have since been 

 discovered to belong to this tribe. They were 

 thicker at one end than the other ; extended and 

 contracted themselves at pleasure j and had, in ad- 

 dition, a leaping motion, frequently springing full 

 half an inch from the paper on which he examined 

 them. The ears were put into water, with gauze 

 tied round them ; but, notwithstanding this care, the 

 flies, escaped, after their developement, without 

 being seen. Mr. Marsham wrote to several friends, 

 requesting their attention to this subject ; in con- 

 sequence of which, an accurate investigation was 

 immediately set on foot. 



It appears that these larvse take their station in 

 the longitudinal furrow of the grain? to the bottom 

 of which they seem attached. Here probably suck- 

 ing the milky juice which swells the grain, and thus 

 depriving it of part, and in some cases, perhaps, of 

 the whole of its moisture, they occasion it to shrink 

 up, and become what the farmers call pungled. 

 They infect several grains in the same ear, and some 

 ears have been observed in which even a fourth of 

 the grain was either destroyed, or very materially 

 injured by them. The late sown wheat always 



