The destruction we speak of has been committed by clubs and societies established for the purpose; but, as their members are mostly filled up with all sorts of prejudices—few being naturalists, or even accurate observers—it becomes daily a matter of more pressing importance that middle-class education, if not National-school teaching, should recognise the value of the natural sciences. 2. The _Gout-fly_ (_Chlorops glabra_) and the _Saw-fly_ (_Sirex pygmæus_) both lay their eggs below the first node or knot of the young plant, which, as soon as they hatch, form maggots that eat out the substance of the stems and the nodes, which thus become weakened and ultimately break off, or, if left standing, the ears of corn as they appear will be dried, whitened, and infertile. In these, as in most cases of insect attacks, we have an occasional blight of such extent as to destroy whole crops, against which we are almost powerless, as we know so little of the economy of the creatures by whom the mischief is caused; still, there can be little doubt but that their periodical appearance, to the extent to cause them to be recognised as _blights_, is due to the thinning of their enemies; and we have always observed that a paucity of the _Hirundines_—the swallow tribe of birds, their greatest enemies—is coupled with a great increase of the smaller insects which it is the vocation of swallows, bats, and others of the hawking insectivorous creatures, to take on the wing. 3. The _Wheat-midge_ (_Cecidomyia tritici_), also called the Hessian-fly, is sometimes very destructive to the wheat crop. In 1860 we observed the effects of this creature to a greater extent than we have before known, in not a few instances rendering the crop scarcely worth reaping. Upon this creature we sent the following notice to the _Agricultural Gazette_ for August 30, 1862:— The wheat-midge (_Cecidomyia tritici_) has been so destructive for the last two or three years, that every fact connected with its history ought to be of great interest. Curtis tells us that “in Scotland one-third of the crop was lost, and the farmers suffered severely in 1828 and the three following years;” whilst “in Suffolk the yield[19] of wheat was one-third less in some districts in 1841 than was expected.” [19] We believe this creature to be one of the most common causes of deficient yield, so that a knowledge of its history is all-important in estimating the value of a crop, which, as a rule, we should always put lower in the seasons when this blight abounds. The presence or absence of this insect is so important as affecting the yield, that we now never fail to look for it in every crop upon which we would offer a judgment in this respect.