The plumule either pushes out from the same end of the caryopsis as the root (e.g. Wheat, Rye) or drives its way between the coats to the opposite end (e.g. Barley) and appears as a pointed cylinder of rolled leaves (the “spear”) the outermost of which is sheath only, no lamina being developed. As Darwin showed, the pointed apex of such a plumule is hardened, facilitating the piercing of the soil above, and when the blade attains the open air it performs spiral movements during growth, indicating that similar attempts to rock from side to side have aided the plumule in forcing its way through the soil. It has also been shown that the apices of roots and plumules are sensitive to differences of temperature, of light-intensity, moisture and contact, all of which aid the seedling in establishing its position in the soil and in liberating the “spear.” For particulars the student should read Darwin’s _Power of Movement in Plants_. With regard to the established seedlings of grasses, many interesting details of structure are to be found in them. I have not sufficient material to draw up a diagnostic arrangement of grass-seedlings, but it is evident that such could be done. It may be useful to illustrate this by the following tabular view of the characters of the larger seedlings of our common cereals, in part adapted from Vesque and Percival; though I find that some variations may occur, especially in the development of the auricles. SEEDLINGS. I. First expanded aerial leaves broad, bright green, with 18-24 ribs. _Barley._ The blade tends to twist to the left: auricles, when well developed, long, pointed, and claw-like, embracing the glabrous sheath in front. Ligule long, membranous, pointed and irregularly toothed. The plumule emerges at the upper end of the grain, and the embryo has 5-6 secondary roots. II. First aerial leaves narrower, with not more than 11-13 ribs. A. _Ligule long, rounded and toothed._ _Wheat._ The blade tends to twist to the left: auricles filiform and embrace the densely pubescent sheath. Leaves green. Embryo with three roots. B. _Ligule short and toothed. Leaves with a reddish cast._ (_a_) Blade and sheath softly hairy, the latter with scattered long hairs, the former tending to twist to the left. _Rye._ The first leaf-sheath purple. Auricle-claws more triangular and smaller than those of wheat, and the accompanying bristles are fewer and shorter. Embryonic roots four. (_b_) Blade and sheath glabrous or merely ciliate or silky, the former tending to twist to the right. _Oat._ Auricles filiform. The plumule emerges above. The embryo has three roots.