THE BARLEY-STRAW INSECT. 553 



when the grain is harvested. When the barley is threshed, 

 numerous small pieces of diseased straw, too hard to be 

 broken by the flail, will be found among the grain. Some 

 of these may be separated by the winnowing-machine, but 

 many others are too large and heavy to be winnowed out, 

 and remain with the grain, from which they can only be 

 removed by the slow process of picking them out by hand. 



In the winter of 1829, Cheever Newhall, Esq., furnished 

 me with a few pieces of diseased barley-straw, each of which 

 contained several small whitish maggots. Since that time 

 this affection of the barley has only once fallen under my 

 notice, though I have reason to think that it continues to 



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prevail in many parts of Massachusetts. Each maggot was 

 imbedded in the thickened and solid substance of the stem, 

 in a little longitudinal hollow, of the shape of its own body ; 

 and its presence was known by an oblong swelling upon the 

 surface. In some pieces of straw the swellings were so 

 numerous as greatly to disfigure the stem, the circulation 

 in which must have been very much checked, if not de- 

 stroyed. Early in the following spring these maggots en- 

 tered the pupa or chrysalis state, and on the loth of June 

 the perfected insects began to make their escape through 

 minuto perforations in the straw, which they gnawed for 

 this purpose. Seven of these little holes were counted in 

 a piece of straw only half an inch in length. The insects 

 continued to release themselves from their confinement till 

 the 5th of July, after which no more were seen. Much 

 to my surprise, they proved to be minute, four-winged flies, 

 belonging to the genus Eurytoma. Supposing these insects 

 to be parasites, in accordance with the known habits of 

 others of the same family, I described them as such, under 

 the name of Eurytoma Hordei (so called from Hordeum, 

 the Latin for barley), in the " New England Fanner,'' for 

 July 23, 1830,* and in the first edition of this work. It 

 was then my belief that the true culprits, or original cause 



* Vol. IX. p. 2. 

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