When walking along the sandy bank of a river, you must frequently have trodden under foot a low, almost crawling herb, remarkable for its violet-red spikes, which, three to five in number, are arranged like the fingers of a hand, on the summit of a short curving stem. [Illustration: FIG. 24.--(P. 93.)] This glaucous-leaved herb is the _Panicum dactylon_ (_i.e._, fingered-millet) of Linnæus. The long trailing _rhizomes_, joined to some less prominent characters, have been sufficient for some botanists to create a special genus, _Cynodon_, or _Kynodon_ (a Greek word, signifying literally "Dog's-tooth"), and to change the Linnean denomination of our grass into _Cynodon dactylon_. It is seldom met with in cultivated land; but in such a locality as we have already described, and sometimes on open sandy shores, where the summer sea comes with a gentle ripple and a subdued music, it may frequently be found. Its long, tough runners creep through and over the loose soil for many yards, rooting at every joint, and furnished with flat, rather short leaves, of a glaucous hue. The flowers grow in narrow, linear spikes, arranged at the top of a short leafy stem in the form of an umbel, and give the grass, when in bloom, a very peculiar and characteristic aspect. But if the _Cynodon dactylon_ is rare in cultivated fields, the _Triticum repens_--commonly called couch-grass, but, in our opinion, the true and genuine dog's-tooth--is particularly abundant. (See Fig. 23.) Its long subterranean stems increase with astonishing rapidity, and if the smallest fragment be left in the soil, it will vegetate, and speedily extend itself, until it becomes almost impossible to extirpate it. It is a kind of wild barley, with stiff leaves of a moderate length, and of a bluish tint, and a double spike, composed of clusters of four to six flowers, each crowned by a narrow ridge. We must not confound the _Triticum repens_ with the _Elymus caninus_ of Linnæus, which has no trailing underground roots like the former. It differs also from the latter in the roughness of _each_ side of its leaves,--only one side of the leaf of the _Triticum repens_ being rough,--and in the crests which rise above the flowers. Was the dog's-tooth known to the ancients? Undoubtedly, for the dog's-tooth flourishes in all climates,--is truly cosmopolitan. But it is difficult to decide whether their _Agrostis_ and their _Gramen_ apply to the above-mentioned species. * * * * *