24 CORN AND GRASS. 



here I immediately found puparia at the lowest part of the shoots, 

 which were plainly stunted by the presence of the infestation. 



The flax-seeds were usually covered by the sheathing leaf, but were 

 easily to be found on careful examination, as, from the stunted and 

 small size of the stems (irrespective of their length), the slight lump 

 caused by the presence of the " flax-seed " was noticeable as bulging 

 out beneath the thin leaf in a way which would not have been 

 observed on a moderately well-developed stem. These stems were so 

 thin that there was very little room for numbers on one stalk, but I 

 found quantities of stalks infested by one or two, and in one case by 

 three, flax-seeds. The infestation was mainly (if not entirely) at the 

 bottom, or near the bottom, of the stems. 



The " flax-seeds " corresponded with our English specimens in 

 size, shape, and colour ; they were just the same tint of brown, and 

 the little pinch-in near one end (as if a rail had been pressed on the 

 chrysalis case) was clearly noticeable. On removing the contents of 

 one " flax-seed" case which was not much advanced, I found that the 

 maggot within was clearly that of a Cecidomyia, by reason of it 

 possessing an "anchor-process," or breast-bone as it is sometimes 

 called, which is one characteristic of Cecidomyideous larvas, and, on 

 further examination, the free extremity of this minute process, which 

 lies beneath the body of the larva at the head end, quite precisely 

 accorded, in its bifid shape, with that of the larva of the Hessian Fly, 

 the Cecidowi/ia destructor. 



I have entered on the description of this unusual form of effects of 

 Hessian Fly on the attacked plants at some length, as (though extra 

 British) a locality about half-way between Paris and Calais is not very 

 far from our own shores, and without careful examination the plants 

 affected, as above mentioned, might so easily be passed by as suffering 

 from some other attack, that it can do no harm to notice this form of 

 neighbouring Continental development. 



We are well acquainted here with the very best methods of pre- 

 vention and remedy, but in the above case, as it was of great importance 

 to stamp out a previously unobserved attack, and also difference in 

 climate might allow different measures to be brought to bear, I 

 suggested that, if possible, it would be desirable to fire the stubbles of 

 the attacked fields, and so stainjj out the infestation without delay.''= 



* By pevtaission of Mr. J. J. Willis, through ^vhose hancts the infested plants 

 were forwarded to me, I gave a description of this attack in the ' Agricultural 

 Gazette ' for Sept. 21st, a portion of which description is repeated above. 



