ping the heads and examining the bare rachis. The internodes, or joints, from which the corns spring are thus exposed, and it will be noticed that there are from six to seven internodes in one inch of the rachis of the Chevalier, and in the Goldthorpe from nine to ten.1 Remove the Basal Bristle from a Corn of Goldthorpe Barley and Examine it with a Pocket Lens or a low Microscopic Power. It will be found to be covered with long hairs, a characteristic which all barleys of the Goldthorpe type possess. On the other hand, the basal bristle of a barley of the Chevalier type (H. distichum) may be covered with either very short hairs or long ones. This depends on the variety of the type. The true Chevalier variety possesses very short hairs; on the other hand the Archer variety and some others possess long hairs somewhat resembling those of the Goldthorpe type (H. zeocriton). Compare a Sample of Threshed Goldthorpe Barley with a Sample of Chevalier Barley.-The skin of the Goldthorpe is somewhat "greasy" in appearance, and does not adhere so closely to the corn as in the Chevalier. Examine the Lower Ends of Goldthorpe Corns on the Dorsal Side.-A small dimple or transverse furrow may be noticed in the skin near the ex Samples of threshed barley frequently contain portions of rachis, and these fragments will often assist the observer in determining the nature of the samples. tremity of the lower end of some of the corns. This dimple is characteristic of the Goldthorpe type of barley, but is not always observed owing to fracture of the corn during the threshing process at the point where the dimple is situated. Compare a Head of H. vulgare with H. hexastichum. - Both are six-rowed barleys, but the head of H. vulgare is narrower than that of H. hexastichum. It will be noticed that the internodes from which the corns spring are more widely separated in H. vulgare than in H. hexastichum. Note that the general appearance of the head of H. hexastichum is somewhat square in appearance, hence the name "square-headed barley" sometimes applied to it. (See Figs. 11 and 12.) Remove the side rows of corns from heads of H. vulgare and H. hexastichum, leaving the middle rows undisturbed, thus converting the six-rowed heads into two-rowed heads. Compare the two artificially produced two-rowed heads with heads of Chevalier and Goldthorpe barley. It will be noticed that the general features of the head of H. vulgare are markedly similar to those of the Chevalier, and that the head of H. hexastichum bears a strong resemblance to that of the Goldthorpe. It is believed that these resemblances may indicate a near kinship in species of Chevalier and H. vulgare, and of Goldthorpe and H. hexastichum. (See Munro and Beaven, Journal of the Royal Agricultural Society, 1900, p. 185.) PART II. ANATOMY OF THE BARLEY CORN. Bisect a soaked barley corn longitudinally through the ventral furrow with a knife. Observe that the greater bulk of the grain is composed of a white, starchy mass, called the endosperm, and that at the base of the corn there is a small, yellowish bud. The bud is the embryo, or living germ of the corn, which eventually grows into the young barley plant. Carefully remove the thick outer skin from another well-soaked corn, and note that below the thick false skin there is an extremely thin skin, which completely envelops both the embryo and the endosperm of the grain. This is the true skin of the corn, and consists of several layers, these being the remains of the walls of the ovary and ovule, which contained the embryo-sac from which the corn has developed. (See Figs. 4 and 6.) Note also that at the base, or germ end, of the corn, the two lodicules previously observed in the barley flower at the base of the ovary are now found compressed between the thick paleæ and the thin true skin of the corn, thus further demonstrating the relation of the barley corn to the barley flower. Remove the Thin Skins enveloping the Embryo and Endosperm of a Barley Corn, and Observe that the Embryo may be Easily Detached from the Endosperm without Injury. This indicates that there is no direct connection between the embryo and endosperm, but that they merely adhere together. This observation is of much importance in connection with the germination changes of the barley corn which will be studied later on. HISTOLOGY OF THE BARLEY CORN. Cut thin Longitudinal Sections of a Barley Corn which has been Soaked in Water for about twentyfour hours, in the Plane of the Ventral Furrow of the Corn. This may be done with a sharp razor, |