The great weed-army which infests farms and gardens in the British Islands numbers about one hundred and thirty species, and consists mainly of two great classes, namely, annuals (fruitful only once) and perennials (capable of producing flowers and fruit time after time). About a dozen, however, are biennials; four of these are thistles; and the most familiar of the remainder are the foxglove and the hemlock. Some of the most troublesome farm and garden pests are perennials, and among these, the most mischievous in their rapidity of growth and tenacity of life are the greater and lesser bindweeds (_Convolvulacea_) and the couch-grass (_Triticum repens_). Unless the soil be well dug and pulverised and thoroughly sifted, the attempt to eradicate either of these will be useless; every half-inch of the white crinkled roots of the bindweed or bit of couch-grass to which roots are attached will grow. The greater bindweed, perhaps, is the most difficult to get rid of, and is especially troublesome among evergreens. The tender, semi-transparent shoots stand quite erect under evergreens until they touch the lower branches; they then make rapid growth, and quickly cover the whole head of a laurel, bay, laurustinus, or rhododendron with a thick mantle of light-green leaves, twisted stems, and snow-white trumpet-shaped flowers. Beautiful in its way, no doubt; but what of the handsome shrubs it has stifled in its fatal caresses, and what of the weeks of hard labour that must be expended in the attempt to eradicate the pest? In Italy, however, the white, underground stems of couch-grass are carefully gathered by the peasantry, taken to market in bundles, and sold as food for cattle and horses. They contain a considerable amount of starch. A variety of couch called matt grass is extensively used in Holland for binding together the sandy dunes and flats by the sea. Coltsfoot is a very troublesome weed; a variegated form of it, with handsome, bold, cream-edged leaf, is wonderfully persistent in forcing its way to other feeding-grounds. In one case under our own observation, its roots, which are tender and brittle, found their way from a bed, beneath a four feet margin of turf and an eight feet wide gravel path. The only place where one is not likely to find the root is where it was planted! In the case of the weeds hitherto particularised, it is useless to remove the part appearing above ground; and it is also so with several of the thistles; unless cut beneath the crown or collar, the result is simply to force the plant to make a fresh effort by throwing out numerous side-shoots.