7. The moth that visits granaries (_Tinia granella_) may here be adverted to. The presence of the larvæ of the little grain moth may soon be ascertained in the granary, when one finds several grains of corn united by a web, to which will be attached bunches of small granules, which are the exuviæ of the one or two caterpillars belonging to each group of corns. The best method of preventing this is thorough cleanliness, light, and ventilation in the granary. If, however, the moth has got possession, then we recommend sulphur to be burnt in iron pans—old saucepan lids are as good as anything—stopping up all the crevices. This will be an effectual remedy, not only for the moth, but for the weevils and other insect pests; and if a pound of sulphur be occasionally burnt in the barn, even rats must succumb to the gas which is generated. 8. The _Meal-worm Beetle_ (_Tenebrio molitor_), which generates commonly in the meal-bins of this country, and the _T. obscurus_, which has been introduced in American flour, are two forms of beetle, the larvæ of which are “meal-worms.” These are best prevented by not keeping too large a store of flour, always having this dry and in the best condition, and storing, as far as possible, in a clean, light, and airy position. Indeed, as Curtis remarks, “Cleanliness is the best guard against these insects;” and we cannot better conclude this chapter than by further quoting the following from this excellent author:— In looking back to the variety of insects that feed upon corn, and the multitudes that are often congregated in one heap, there can be no doubt that a very large portion must be occasionally ground up with the corn and consumed by the public. This is not only a disagreeable fact, but it may be the source of very serious consequences, for I think it not improbable that many diseases might be traced to the insects which are converted with the infested flour into bread, amounting to such a large percentage, that if they have the slightest medicinal or deleterious qualities, it is impossible to deny the influence they must exercise upon the human system. I have known bushels of cocoa-nuts, which were every one worm-eaten and full of maggots, with their webs, excrement, cast-off skins, pupæ, and cocoons, all ground down to make chocolate, flavoured, I suppose, with vanilla! CHAPTER XXX. SCIENCE IN THE CULTIVATION OF CORN. The object of the present chapter will be to point out the principles concerned in the more immediate acts connected with the cultivation of corn. In so doing in the present case, as in the discussion of the preceding subjects, it may not be out of place here to state that it has not, nor will it be, our object to enter into the every-day practical details of crop-management, but to dwell more particularly upon those points in cultivation which may be said to belong more especially to the science of the subject.